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Source: ucmp.berkeley.edu/help/timeform.php
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Rephotography, translations, and extra text: Don Hitchcock 2015
Source: Display at the Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Earth during the late Precambrian, circa 650 million years ago
This map illustrates the break-up of the supercontinent, Rodinia, which formed 1100 million years ago, and the positions of the resulting continents as at 650 million years ago.
The Precambrian Era comprises all of geologic time prior to 600 million years ago. The Precambrian was originally defined as the era that predated the emergence of life in the Cambrian Period. It is now known, however, that life on Earth began by the early Archean and that fossilised organisms became more and more abundant throughout Precambrian time.
The two major subdivisions of the last part of the Precambrian are the Archean (oldest) and the Proterozoic. Rocks younger than 600 Mya are considered part of the Phanerozoic.
Credit: Plate tectonic maps and Continental drift animations by C. R. Scotese, PALEOMAP Project (www.scotese.com)
Photo: © 2010, C. R. Scotese
Proximal source: www.scotese.com/precambr.htm
Text: Various sources
Banded iron formation
The coloured bands in this rock reveal a dramatic increase in atmospheric oxygen, a critical moment for the evolution of life on Earth.
More than three billion years ago, cyanobacteria in our planet's young oceans began to produce oxygen through photosynthesis. This oxygen combined with dissolved iron in the sea to form insoluble iron oxide, which separated out of the water and sank to the seafloor.
As it settled, bands of red and grey iron oxide developed between layers of silica-rich sediment. The intricate and dramatic layers in this rock signal a turning point in Earth's history: the Great Oxygenation Event, or GOE. This led to an increased diversity of life forms and the appearance of new minerals.
Before the Great Oxygenation Event, the Earth's atmosphere was primarily made up of nitrogen (N2), carbon dioxide (CO2), and trace gases. There was almost no free oxygen, and the only fixed nitrogen made available to the first bacteria was produced by lightning strikes.
As cyanobacteria began producing oxygen, the levels of free O2 in the atmosphere started to increase. However, this oxygen was initially absorbed by various materials on Earth, including dissolved iron in the oceans, forming banded iron formations. Once these sinks were saturated, free oxygen began to accumulate in the atmosphere.
Cyanobacteria also possess the ability to fix atmospheric nitrogen through the enzyme nitrogenase, which catalyses the conversion of nitrogen gas (N2) into ammonia (NH3) or related nitrogen compounds that can be used to form amino acids, nucleotides, and other essential biological molecules.
However, the oxygen levels still remained low for almost 2 billion years after the Great Oxygenation Event. The exact reason for these low oxygen levels is still a mystery.
The oxygen levels eventually increased substantially when plants evolved, and separated nitrogen fixation from photosynthesis. Plants themselves do not have the ability to fix nitrogen directly. They rely instead on diazotrophic bacteria (bacteria that can fix nitrogen) that live in or on their roots. This process is called symbiotic nitrogen fixation.
Source: Western Australia, circa 2.6 billion years old, AQ-PEG-2016-33. This rock was donated by Rio Tinto and came from the traditional lands of the Eastern Guruma People in the Pilbara region of Australia.
Photo: Don Hitchcock 2018
Proximal source: The Natural History Museum, London
Text: The NHM and various other sources
The Ediacarian
The Ediacaran is a geological period of the Neoproterozoic Era that spans 96 million years from the end of the Cryogenian Period at 635 Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last period of the Proterozoic Eon as well as the last of the so-called 'Precambrian supereon', before the beginning of the subsequent Cambrian Period marks the start of the Phanerozoic Eon, where recognisable fossil evidence of life becomes common.
The Ediacaran Period is named after the Ediacara Hills of South Australia, where trace fossils of a diverse community of previously unrecognised lifeforms (later named the Ediacaran biota) were first discovered by geologist Reg Sprigg in 1946. Its status as an official geological period was ratified in 2004 by the International Union of Geological Sciences (IUGS), making it the first new geological period declared in 120 years.
Text above from Wikipedia.
Dickinsonia costata Ediacara, Australia.
Dickinsonia is a genus of extinct organism, most likely an animal, that lived during the late Ediacaran period in what is now Australia, China, Russia, and Ukraine. It is one of the best known members of the Ediacaran biota. The individual Dickinsonia typically resembles a bilaterally symmetrical ribbed oval. Its affinities are presently unknown; its mode of growth has been considered consistent with a stem-group bilaterian affinity, though various other affinities have been proposed. It lived during the late Ediacaran (final part of Precambrian). The discovery of cholesterol molecules in fossils of Dickinsonia lends support to the idea that Dickinsonia was an animal, though these results have been questioned.
Dickinsonia fossils are known only in the form of imprints and casts in sandstone beds. The specimens found range from a few millimetres to about 140 cm in length, and from a fraction of a millimetre to a few millimetres thick. They are nearly bilaterally symmetric, segmented, round or oval in outline, slightly expanded to one end (i.e. an egg-shaped outline). The rib-like segments are radially inclined towards the wide and narrow ends, and the width and length of the segments increases towards the wide end of the fossil. The body is divided into two by a midline ridge or groove, except for a single unpaired segment at one end, dubbed the 'anterior-most unit' suggested to represent the front of the organism. It is disputed whether the segments are offset from each other following glide reflection, and are thus isomers, or whether the segments are symmetric across the midline, and thus follow true bilateral symmetry, as the specimens displaying the offset may be the result of taphonomic distortion. The number of segments/isomer pairs varies from 12 in smaller individuals to 74 in the largest Australian specimens.
The body of Dickinsonia is suggested to have been sack-like, with the outer layer being made of a resistant but unmineralised material. Some specimens from Russia show the presence of branched internal structures. Some authors have suggested that the underside of the body bore cilia, as well as infolded pockets.
Dickinsonia is suggested to have grown by adding a new pair of segments/isomers at the end opposite the unpaired 'anterior-most unit'. Dickinsonia probably exhibited indeterminate growth (having no maximum size), though it is suggested that the addition of new segments slowed down later in growth. Deformed specimens from Russia indicate that individuals of Dickinsonia could regenerate after being damaged.
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Adapted from Wikipedia
Aspidella terranovica Ediacara, Australia.
Aspidella consists of disk-shaped fossils, with concentric rings and/or centripetal rays. The diameter of circular Aspidella varies from 1 to 180 mm. Most individuals are between 4 and 10 mm, but smaller individuals would presumably have decayed before they could fossilise. Other Aspidella take the form of ellipses, 3–8 cm long and 1–4 cm wide. Most have a central pimple. The rim of all specimens is made up by ridge-edged rays and/or concentric rings.
The rarity of large individuals probably indicates that Aspidella were r-strategists, producing numerous offspring of which most died young. It is most common in deep-water sediments, but is a constituent of most Ediacaran fossil assemblages, including those deposited above storm wave-base. The organisms can reach densities of more than 3000 per square metre.
Just like Ediacaria, Aspidella has initially been considered a scyphozoan jellyfish. This initial designation has been refuted; some specimens have been shown to be the holdfast of some organism, the main body of which extended into the open water but broke off before fossilisation (a few specimens bearing stubs of stalks opposed to the central pimple support this); whereas others represent microbial colonies.
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Adapted from Wikipedia
Earth during the Cambrian, circa 510 million years ago
A mollweide (equal-area) projection map of Earth 510 million years ago, overlain by a black outline of present-day countries in their respective locations.
( Note that Avalonia was a microcontinent in the Palaeozoic era. Crustal fragments of this former microcontinent underlie southwest Great Britain, southern Ireland, and the eastern coast of North America. It developed as a volcanic arc on the northern margin of Gondwana. It eventually broke off, becoming a drifting microcontinent - Don )
The Cambrian was the first period of the Palaeozoic Era, lasting from 542 to 488 million years ago. Prior to the Cambrian, the majority of living organisms were small, unicellular and poorly preserved. It was a time of rapid evolution, when the basic body plans of most modern animals were established. This period is known as the 'Cambrian Explosion' because of the relatively short time it took for such a diversity of life to appear.
Animals included invertebrates like trilobites, graptolites, molluscs, brachiopods, echinoderms, corals, and sponges. Vertebrates (animals with back bones) also appear in the Cambrian, and fish-like creatures swam in the oceans for the first time. All these animals lived in water.
The Cambrian was also characterised by a warmer global temperature than the present day.
The Cambrian was a time of greenhouse climate conditions, with high levels of atmospheric carbon dioxide and sometimes low levels of oxygen in the atmosphere and seas. Upwellings of anoxic deep ocean waters into shallow marine environments led to extinction events, whilst periods of raised oxygenation led to increased biodiversity.
Some Cambrian curiosities are still with us today. Animals such as sponges, jellyfish and anemones look fairly similar to their Cambrian ancestors.
The term Cambrian is derived from the Latin version of Cymru, the Welsh name for Wales, where rocks of this age were first studied. It was named by Adam Sedgwick in 1835, who divided it into three groups; the Lower, Middle, and Upper. He defined the boundary between the Cambrian and the overlying Silurian, together with Roderick Murchison, in their joint paper 'On the Silurian and Cambrian Systems, Exhibiting the Order in which the Older Sedimentary Strata Succeed each other in England and Wales'. This early agreement did not last.
Due to the scarcity of fossils, Sedgwick used rock types to identify Cambrian strata. He was also slow in publishing further work. The clear fossil record of the Silurian, however, allowed Murchison to correlate rocks of a similar age across Europe and Russia, and on these he published extensively. As increasing numbers of fossils were identified in older rocks, he extended the base of the Silurian downwards into Sedgwick's 'Upper Cambrian', claiming all fossilised strata for 'his' Silurian series.
Matters were complicated further when, in 1852, fieldwork carried out by Sedgwick and others revealed an unconformity within the Silurian, with a clear difference in fauna between the two. This allowed Sedgwick to now claim a large section of the Silurian for 'his' Cambrian and gave the Cambrian an identifiable fossil record. The dispute between the two geologists and their supporters, over the boundary between the Cambrian and Silurian, would extend beyond the life times of both Sedgwick and Murchison. It was not resolved until 1879, when Charles Lapworth proposed the disputed strata belong to its own system, which he named the Ordovician.
The term Cambrian for the oldest period of the Palaeozoic was officially agreed in 1960, at the 21st International Geological Congress. It only includes Sedgwick's 'Lower Cambrian series', but its base has been extended into much older rocks.
Text: Various sources, including Wikipedia
Image: Scotese, Christopher R.; Vérard, Christian; Burgener, Landon; Elling, Reece P.; Kocsis, Ádám T
Permission: Creative Commons Attribution 4.0 International, via Wikipedia
Text on map added by Don Hitchcock
Life on the platform margin of the Miaolingian sea, North China, during the Cambrian. Based on data from the Linyi Lagerstätte.
Drawing by Dinghua Yang.
Photo: Zhixin Sun, Fangchen Zhao, Han Zeng, Cui Luo, Heyo Van Iten, Maoyan Zhu.
Permission: Creative Commons Attribution 4.0 International
Cephalopods
This image is a reconstruction of Plectronoceras, arguably the earliest known crown-group cephalopod, dating to the Upper Cambrian. Its 14 known specimens come from the basal Fengshan Formation (north-east China) of the earliest Fengshanian stage. None of the fossils are complete, and none show the tip or opening of the shell.
Approximately half of its shell was filled with septa; 7 were recorded in a 2 cm shell. Its shell contains transverse septa separated by about half a millimetre, with a siphuncle on its concave side. Its morphology matches closely to that hypothesised for the last common ancestor of all cephalopods, and the Plectronocerida have been said to be the ancestors of the Ellesmerocerids, the first 'true cephalopods'.
Image: Entelognathus, via Wikipedia
Permission: Creative Commons Attribution-Share Alike 4.0 International licence.
Text: Wikipedia
Chancelloria penctata
Sponge
The Chancelloriids are an extinct family of superficially sponge-like animals common in sediments from the Early Cambrian to the early Late Cambrian.
Their status as true sponges is disputed.
Findspot: Millard County, Utah, USA.
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Wikipedia
Niobella cf. fourneti
Trilobite
From the early Cambrian (circa 500-520 Mya)
Findspot: Landeyran, Hérault, France
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Olenellus chiefensis
Trilobite
The Olenellus genus is restricted to the early Cambrian (540-520 million years ago), making them good index fossils. They have a most distinctive large cephalon containing crescentic eyes, visible in this specimen. This specimen is exceptionally complete, most are only found as a preserved cephalon
( see the major sections of a trilobite in the image below - Don )
Olenellus means small Olenus, and the name Olenus refers to a mythological figure who was turned to stone by the gods.
Findspot: Lincoln County, Utah, USA.
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: www.fossilmuseum.net and Wikipedia
Diagram showing the three major sections of a trilobite.
Photo and text: Ch1902 vector, Sam Gon III raster
Permission: CC0 1.0, Public Domain, via Wikipedia
Megistaspidella triangularis
Trilobite, Cambrian period. It was probably extinct by the end of the Cambrian.
Findspot: Saint Petersburg, Russia.
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Hemimalora_stellaris
Jellyfish
From the early Cambrian (circa 500-520 Mya)
These fossils (sometimes referred to as a mass mortality plate) are almost surely the result of a mass stranding on an ancient Cambrian beach, possibly caused by a storm surge.
( I find it staggering that an animal such as a jellyfish, which is 95% water, could be preserved in such detail after more than 500 million years. Sure, trilobites. Sure, corals and echinoderms. But jellyfish? - Don )
Findspot: Mosinee Wisconsin
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: www.fossilmall.com
Margaritia dorus
Green algae
The first fossils of multicellular green algae appear in the Cambrian strata of the early Palaeozoic Era. Margaritia was a thin, frond-like green, carbonaceous algae resembling modern kelp. Complete Margaritia dorus have also been found in the Burgess shale of Canada and are classified as Chlorophytes, a distinct branch of green algae from the Streptophytes that eventually gave rise to the land plants.
Findspot: Millard County, Utah, USA.
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text adapted from: www.fossilmuseum.net
Circocosmia jinningensis
Circocosmia jinningensis, a burrowing worm, lived buried in the seafloor sediment as animals like Amplectobelua, a group of stem arthropods ( i.e. direct ancestors of modern arthropods - Don ) that mostly lived as free-swimming predators, swam above it.
Circocosmia jinningensis captured prey by turning out the long snout-like pharynx at the front of the animal, and could crawl short distances over the seafloor in search of food.
Findspot: Chengjiang, Yunnan, China
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: www.fossilsoup.com
Gogia spiralis
Gogia is a Cambrian cystoid that is among the earliest and most primitive groups of echinoderms. For this reason they are sometimes called 'dawn crinoids'. They had a vase-shaped body (calyx), covered by plates that were symmetrical and have a bifurcated brachiole, a slender arm-like structure for food-gathering that closely resembled those in cystoids.
Gogia differed from true crinoids in that they had pores along the margins separating the plates, and the type of feeding arms they displayed. The species Gogia spiralis derives its name from its tightly spiraled arms and is only one of three Gogia species to have spiralled arms. Gogia had a vase-shaped body or calyx with irregularly positioned plates. It also had a stalk made up of smaller plates that attached to the sea floor, and food-gathering arm-like structures called brachioles.
Findspot: Richmond, Utah, USA.
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: www.fossilmuseum.net
Earth during the Middle Ordovician, circa 465 million years ago
A mollweide (equal-area) projection map of Earth 465 million years ago, overlain by a black outline of present-day countries in their respective locations.
( Note that Avalonia was a microcontinent in the Palaeozoic era. Crustal fragments of this former microcontinent underlie southwest Great Britain, southern Ireland, and the eastern coast of North America. It developed as a volcanic arc on the northern margin of Gondwana. It is shown here after breaking away from Gondwana, becoming a drifting microcontinent - Don )
Image: Scotese, Christopher R.; Vérard, Christian; Burgener, Landon; Elling, Reece P.; Kocsis, Ádám T
Permission: Creative Commons Attribution 4.0 International, via Wikipedia
Text on map added by Don Hitchcock
Avalonia was a microcontinent in the Paleozoic era. Crustal fragments of this former microcontinent underlie south-west Great Britain, southern Ireland, and the eastern coast of North America. It is the source of many of the older rocks of Western Europe, Atlantic Canada, and parts of the coastal United States. Avalonia is named for the Avalon Peninsula in Newfoundland. (wikipedia)
Life during the Ordovician period (485.4–443.8 million years ago) was diverse and included many different types of marine and land animals and plants:
Marine life
The Ordovician period saw a tripling of marine diversity, with the appearance of many new life forms, including starfish, brittle stars, crinoids, and echinoids. Other marine life included graptolites, trilobites, brachiopods, conodonts, cephalopods, corals, gastropods, red and green algae, and primitive fish.
Graptolites
Graptolites were colonial animals that lived in an interconnected system of tubes. From an initial ’embryonic’, cone-like tube (the sicula), subsequent tubes (thecae) are arranged in branches (stipes) to make up the whole colony (rhabdosome). Each individual animal is called a zooid.
Stomochord: The most distinguishing characteristic of the Hemichordates (which include the graptolites) is a more primitive form of notochord, called a stomochord, that contained a nerve system. The notochord is a cartilaginous skeletal rod supporting the body.
The peduncle is a stalklike part by which an organ is attached to an animal's body, or by which a barnacle or other sedentary animal is attached to a substrate.
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Various sources
Graptolites
Monograptus spiralis
Monograptus is a genus of graptolites in the order Graptoloidea. This particular genus is the last stage of the graptoloid evolution before its extinction in the early Devonian. A characteristic of the genus includes one uniserial stipes (stalk/branch) with very elaborate thecae. This particular genus contains large number of graptolite species and may not be monophyletic.
Taking advantage of the spaces left available at the end of the Cambrian, brachiopods, molluscs, echinoderms (sea stars, crinoids and sea urchins) multiplied and diversified. Thus, some spaces disappeared and new ones continually appeared.
Specimen from the Czech Republic.
Photo: Don Hitchcock 2015
Text and source: Muséum de Toulouse
Additional text: Various sources
Graptolite nomenclature
Didymograptus, a 'tuning fork' graptolid, showing the main parts of the rhabdosome.
The first primitive graptolites, the Dendroidea, appeared in the Lower Ordovician. They were benthic in form, meaning that their colonies were attached to the ocean floor by a root-like base with many branches.
Photo and text: www.bgs.ac.uk, BGS © UKRI
Additional text: https://www.earthsciences.hku.hk
Didymograptus denticulatus
The species Didymograptus denticulatus derives its specific name denticulatus from its toothlike serrations. Graptolites are colonial animals belonging to the hemichordates. The graptolites have a cosmopolitan distribution, and so serve as index fossils in many locations. The Graptoloidea were pelagic, drifting with the currents.
Didymograptus is an extinct genus of graptolites with four rows of cups (thecae). They lived during the Middle to Late Ordovician.
The genus is characterised by its two-branched form, frequently suspended from a circular disk-shaped structure. Didymograptus includes some of the largest known graptolites.
Findspot: Millard County, Utah, USA
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: www.fossilmall.com, www.britannica.com
610
Phyllograptus sp.
Phyllograptus is a graptolite genus of the order Graptoloidea, in the family Phyllograptidae.
Fossils of this genus have been found widely distributed in Early Ordovician sediments (475-473 Mya).
The normal length of a colony of these leaf-shaped animals could reach a length of 35 mm.
They were passively mobile ( i.e. drifting with the current - Don ) planktonic suspension feeders.
Phyllograptus species are excellent index fossils or guide fossils for identifying Ordovician rocks.
Findspot: Millard County, Utah, USA
Photo: Don Hitchcock 2015
Text and source: Muséum de Toulouse
Additional text: Various sources
Echinoderms and Trilobites, identified as Selenopeltis bucci
The Echinoderms are unidentified.
Species in the genus Selenopeltis can reach a length of 115–160 millimetres and a width of 115–130 millimetres. These trilobites show long pleural spines and were a low-level epifaunal detritivore. They lived in the Ordovician period, from the Lower Arenig stage age until the Ashgillian age (478.6-443.7 million years ago).
Epifaunal detritivores refers to organisms that live on the surface of the substrate (the sea floor, rocks, or other surfaces) rather than buried in it. These animals can often be seen moving or living on the ocean floor, but not within it. In addition, these are organisms that feed on detritus, the organic matter that falls to the ocean floor, including dead plants, animal remains, and fecal matter. Detritivores play an important role in breaking down and recycling nutrients back into the ecosystem.
Findspot: Erfoud, Morocco
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Various sources
Asaphus_platyurus
Trilobite.
Coming from the Middle Ordovician deposits of the Wolchow River region near Saint Petersburg, Russia, this is an example of the unusual trilobite Asaphus platyurus. It is known for the dramatically curved genal spines.
Findspot: Saint Petersburg, Russia
Additional text: adapted from www.fossilmall.com/EDCOPE_Enterprises/trilobites/RUT241/RUT241.htm
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Illaenus tauricorniss is a species of trilobites from Russia and Morocco, from the middle Ordovician.
The Latin species name tauricorniss means 'bull-horned', with reference to the shape of the genal spines.
Illaenus tauricorniss can reach a length of about 57 millimetres. These trilobites are without glabella and without articulation of the tail. The cephalon has a high profile and recurved genal spines. Eyes are distant from the axis of the head, situated nearer to the edge. Usually the cephalon is contracted, due to the contraction of the muscles during fossilisation. ( This specimen does not exhibit that contraction - Don )
Findspot: Saint Petersburg, Russia
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Wikipedia
Crinoid
Crinoids are an ancient fossil group that first appeared in the seas of the Middle Cambrian.
Stalked crinoids today live only in the deep ocean, in
quiet water below the lighted zone where it is too dark for
predators to see them. Because they are attached to the
seafloor and can't escape, they would be too vulnerable
to predators in lighted shallow water.
They live and die in such deep water that they are not washed onto beaches by
currents or waves. Living stalked crinoids were originally studied
by dredging in deep water. Now they are also studied by
scientists in deep-sea submersibles. During much of the
Palaeozoic Era (245—5 70 million years ago), stalked
crinoids lived in shallow water where predators could see
them. Apparently they were able to do this because Palaeozoic predators were less efficient than modern predators, the bony fishes.
Text: Wikipedia
Photo: www.fossils-facts-and-finds.com/crinoid.html
Trilobite
Trilobites (meaning three lobes") form one of the earliest known groups of arthropods.
Trilobites existed from the Early Cambrian, and flourished until the Devonian.
By the time trilobites first appeared in the fossil record, they were already highly diversified and geographically dispersed. Because trilobites had wide diversity and an easily fossilised mineralised exoskeleton, they left an extensive fossil record.
Trilobites evolved into many ecological niches. Some moved over the seabed as predators, scavengers, or filter feeders, and some swam, feeding on plankton. Some even crawled onto land. The largest trilobites were more than 70 cm long and may have weighed as much as 4.5 kg.
Text: Wikipedia
Photo: samnoblemuseum.ou.edu
Trilobite Asaphus kowalewskii
This is one of the 35 species of trilobites of the genus Asaphus. Fossils of this species are popular among collectors because of their prominent stalked eyes (termed 'peduncles'), many an inch or more in length.
In the Ordovician period, an inland sea formed in what is now Eastern Europe. The sea contained a remarkably diverse trilobite fauna. Over a dozen species of Asaphus developed in this sea, with many species, including unrelated species, developing long eyestalks in various lengths. That so many species of trilobite developed eyestalks suggests that they were trying to overcome increased turbidity, or there was some sort of massive selective pressure leading these trilobites to bury themselves in the substrate up to their eyes. This species may have lain in wait buried in a benthic layer of loose debris or sediment with only its periscope eyestalks protruding above, looking out for danger or prey.
Findspot: The fossils of this species are found only in the middle Ordovician deposits of the Volkhov River region near Saint Petersburg, Russia.
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Adapted from Wikipedia
Asaphus expansus is one of the older trilobites of the Asaphus series from the Saint Petersburg region of Russia.
Coming from the Lower Ordovician Kunda layer, expansus is believed to be the progenitor of a large majority of the more than 30 Russian Asaphids, including Asaphus kowalewskii, the species with the astonishingly long eye stalks.
Findspot: Saint Petersburg, Russia
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: www.fossilmuseum.net
Trilobite Asaphus cornutus
Asaphus cornutus could grow up to about 6-8 cm in length, though some larger specimens have been found. Its body is somewhat elongate and flattened, with a broad, semi-circular head (cephalon) that has prominent features.
Head (Cephalon): The head of Asaphus cornutus is one of its most distinctive features. It has a pair of large, curved eyestalks that extend outward from either side of the head.
( These eyestalks do not appear to be large in this image because of the angle at which the photo was taken - Don ).
These eyestalks give the species its 'cornuted' (horned) appearance. The head is also equipped with a well-developed glabella (the central lobe of the cephalon), which is slightly raised.
Thorax and Pygidium: The body of Asaphus cornutus is divided into the thorax (the midsection) and the pygidium (the tail part). The thorax consists of several segments that allow for some flexibility, while the pygidium is relatively small, in contrast to the larger head and thorax.
Like many trilobites, Asaphus cornutus had compound eyes, which were made up of numerous individual lenses. These eyes were large and situated on the sides of the head, allowing it to have a wide field of vision.Asaphus cornutus
Asaphus cornutus was probably a benthic organism, meaning it lived on the sea floor. It may have been a scavenger or detritivore, feeding on organic material on the ocean floor, though some suggest it may have been capable of hunting smaller prey.
The characteristic appearance of Asaphus cornutus makes it a favourite among fossil collectors, and its fossils are often found in sedimentary rock deposits that were once part of shallow marine environments, especially in what is now modern-day Europe.
Findspot: Saint Petersburg, Russia.
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Various sources
Cybele bellatula is the fossil of an extinct trilobite from the Lower Ordovician. The genus was named after Cybele, the ancient Oriental and Greco-Roman goddess representing Gaia, the deified Earth Mother. The specific name means 'pretty, little' and is used as a term of endearment.
Cybele bellatula grew to a maximum of about 45 millimetres with an intriguing morphology; it shows deep, thin lateral furrows, long eye-stalks, exceeding the cephalon in length, and a tiny visual surface; its eye-stalks are about 0.5 mm in diameter; its glabella is covered in tubercles. This trilobite fossil occurs in Russia, Sweden and Norway.
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Adapted from Wikipedia
Gomphoceras is a questionable nautiloid cephalopod genus assigned to the Oncocerida. The family to which it might belong is undetermined.
Gomphoceras is generally short but rapidly expanding, straight to slightly stomach-like.
Gomphoceras represents a group of early cephalopods that were part of a diverse and rapidly evolving marine ecosystem. Although they are long extinct, they provide valuable insight into the early stages of cephalopod evolution, which eventually gave rise to more complex forms like squid, octopus, and cuttlefish.
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Adapted from various sources
Trocholites hospes is from the Middle Ordovician, 464 - 461 Mya.
Trocholites is a genus in the class Cephalopoda from the Middle and Late Ordovician with a gradually expanding, weakly ribbed shell. The whorls are in contact.
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Adapted from various sources including www.mindat.org
Pleurocystites squamosus, an Echinoderm from the late Ordovician.
Pleurocystites (meaning rib bag) is a genus of rhombiferan echinoderms from the class Cystoidea. Fossil Pleurocystites sp. are known from Europe and North America.
Pleurocystites squamosus grew to a height of 2 cm to 6 cm, and fed on tiny, floating plankton. The most distinctive feature of cystoids was the presence of a number of pores in the rigid skeleton encasing the body. These were most likely respiratory in nature, allowing fluid to flow in or out of the body.
( Note the drawing of Pleurocystites squamosus below - Don )
Findspot: Simcoe County, Ontario, Canada
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Adapted from various sources, including www.fossilera.com
Group of Cystideans.
A, Caryocrinus ornatus, Upper Silurian, America; B, Pleurocystites squamosus, showing two short 'arms', Lower Silurian, Canada; C, Pseudocrinus bifasciatus, Upper Silurian, England; D, Lepadocrinus Gebhartii, Upper Silurian, America.
Drawing and text: Nicholson (189(?))
Gastropod, Cyclonema humerosum
Diagnostic features include:
• Deeply channeled suture
• Angular shoulder
• Broad ramp
• Whorl profile straight to concave between sutures
• Variable ornament generally consists of three orders of 9-10 spiral lines crossed by growth lirae
Findspot: Hamilton, Ohio, USA
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: www.ordovicianatlas.org
( Click on the thumbnail above to see the original full size image without the lettering identification - Don )
Brachiopods
• A Rafinasquina ponderosa - One of the larger brachiopods. Rectangular in shape with the pedicle valve concave toward the margin and the brachial valve convex. Note the shell pattern of alternating more prominent rays with several less prominent rays in between.
Text: drydredgers.org/brachraf.htm
• B Hebertella sp. - Hebertella is a medium-size, brachiopod found in upper Ordovician strata. It belongs to the brachiopod order Orthida. Hebertella has a subquadrate to subelliptical outline, and a biconvex (usually unequally biconvex), to convexo-concave, lateral profile. The dorsal (brachial) valve is generally somewhat hemispherical, thicker, and more convex than the ventral (pedicle) valve. Sulcus and fold are moderately (but variably) developed. The sulcus is a depression along the midline of the pedicle (ventral) valve, and the fold is a corresponding raised area along the midline of the brachial (dorsal) valve. Valves are ornamented by fine costae or costellae (thin to very thin ribbing). The genus is distinguished by the shape of muscle scars on the inside of its valves.
Text: Walker (1982), Wright & Stigall (2013)
• C Leptaena richmondensis
Diagnostic features include:
• Subrectangular, semicylindrical shape
• 12 or more concentric rugae (ripples) which cross the costae
• Sides are expanded and it is convex
• Hinge line is straight
• Ventral valve is flat
Text: www.ordovicianatlas.org
Findspot: Franklin, Indiana, USA
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Bryozoa (also known as moss animals) are a phylum of simple, aquatic, invertebrate animals, nearly all living in sedentary colonies. Typically about 0.5 millimetres long, they have a special feeding structure called a lophophore, a 'crown' of tentacles used for filter feeding. Most marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters.
Findspot: Morocco
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Wikipedia
Diagram of a portion of a colony of an encrusting bryozoan.
Source: adapted from Hayward & Ryland (1995))
Eldonia berbera
Eldonia is a problematic, soft-bodied animal. This is to say, it does not fit conveniently into any existing phylum. In this specimen, the C-shape digestive tract can be seen as well as the margins of the organism.
( I find this statement above amazing. I am used to scholars of the organisation of phyla knowing exactly where every organism fits in the scheme of things. There is a glitch in the matrix - Don )
Findspot: Erfoud, Morocco
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: www.fossilera.com
Land life
The Ordovician period saw the first colonisation of land by plants and arthropods. Plants likely evolved in the ocean, then moved to freshwater, and finally to land. The first animals to leave the ocean were probably modified arthropods.
Other life
The Ordovician period also saw the evolution of jawless fish, which were the first true vertebrates. These bottom-feeders were covered in armour plates.
Reconstruction of an early jawless fish, Arandaspis, from central Australia.
Arandaspis looked like a tube of bony plates about 15 cm long, with headlamp style forward-facing eyes and a circular mouth. It had no fins, and probably lived on the sandy bottom of the sea eating small animals it sucked out of the sediments.
It lived in the Ordovician period, about 480 to 470 million years ago.
Photo: Nobu Tamura
Permission: Creative Commons Attribution-Share Alike 3.0 Unported
Text: Long (2024)
The Ordovician period ended with a mass extinction that was the second largest in history.
Earth during the Middle Silurian, circa 430 million years ago
A mollweide map of Earth at the middle of the Silurian, 430 million years ago, overlain by a black outline of present-day countries in their respective locations.
The Silurian is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago (Mya), to the beginning of the Devonian Period, 419.2 Mya. The Silurian is the third and shortest period of the Palaeozoic Era, and the third of twelve periods of the Phanerozoic Eon. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out.
One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, and three groups of arthropods (myriapods, arachnids and hexapods) became fully adapted to the land.
Vascular plants are plants that have lignified (woody) tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialised non-lignified tissue (the phloem) to conduct products of photosynthesis. The group includes most land plants other than mosses.
Another significant evolutionary milestone during the Silurian was the diversification of jawed fish, which include placoderms, acanthodians (which gave rise to cartilaginous fish) and osteichthyan (bony fish, further divided into lobe-finned and ray-finned fishes) although this corresponded to sharp decline of jawless fish such as conodonts and ostracoderms.
Image: Scotese, Christopher R.; Vérard, Christian; Burgener, Landon; Elling, Reece P.; Kocsis, Ádám T
Permission: Creative Commons Attribution 4.0 International, via Wikipedia
Text on map added by Don Hitchcock
Gnathostome, reconstruction.
Gnathostomata are the jawed vertebrates. Gnathostome diversity comprises roughly 60 000 species, which accounts for 99% of all living vertebrates, including humans. Most gnathostomes have retained ancestral traits like true teeth, a stomach, and paired appendages (pectoral and pelvic fins, arms, legs, wings, etc.). Other traits are elastin, a horizontal semicircular canal of the inner ear, myelin sheaths of neurons, and an adaptive immune system which has discrete lymphoid organs (spleen and thymus).
It is now assumed that Gnathostomata evolved from ancestors that already possessed a pair of both pectoral and pelvic fins. Until recently these ancestors, known as antiarchs, were thought to have lacked pectoral or pelvic fins. In addition to this, some placoderms (extinct fish with bony plates) were shown to have a third pair of paired appendages, that had been modified to claspers in males and basal plates in females — a pattern not seen in any other vertebrate group.
The Osteostraci (bony armoured jawless fish) are generally considered the sister taxon of Gnathostomata.
Jaw development in vertebrates is likely a product of the supporting gill arches. This development would help push water into the mouth by the movement of the jaw, so that it would pass over the gills for gas exchange. The repetitive use of the newly formed jaw bones would eventually lead to the ability to bite in some gnathostomes.
In Devonian waters, the body of armoured fish was protected by bony plates.
All have a cartilaginous skeleton and fins, which are covered with 'placoderm' plates or protected by an ostracoderm shell.
All Placoderms and Ostracoderms (except for lampreys and hagfish) disappeared at the end of the Devonian period.
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Adapted from Wikipedia
Life reconstruction of Shenacanthus vermiformis
Dawn of Fishes—Early Silurian Jawed Vertebrates Revealed Head to Tail
Editor: LI Yuan | Sep 29, 2022, Nature, Prof. ZHU Min
The Gnathostomata or jawed vertebrates, which include not only almost all the backboned animals you see in zoos and aquariums but humankind as well, have a mysterious origin. The so-called molecular clock, which deduces the age of the most recent common ancestor of two animals by evaluating the difference between the two sets of DNA, suggests that the most recent common ancestor of all modern jawed vertebrates lived 450 million years ago during the Ordovician period. As a result, the origin of jaws cannot be later than that.
However, the fossil record of jawed vertebrates only becomes abundant from the Early Devonian (~419 million years ago), i.e., the beginning of the "Age of Fishes." Only in the past 10 years have scientists found several complete jawed fishes from the Late Silurian (~425 million years ago). Even so, these records are still more than 25 million years later than when jaws should have originated. The dearth of earlier fossils means that jawed vertebrates are a 'ghost lineage' in the early Silurian.
The remarkable discovery of complete early Silurian jawed fishes is the result of 20 years of continuous effort by the authors searching for fossil fishes in all possible Silurian rock strata in China. The breakthrough was finally made in late 2020, when complete early Silurian fishes were found in Xiushan County, Chongqing.
Shenacanthus vermiformis is very small, it is an early shark relative. However, all the sharks we know are covered in tiny scales, or at most small mosaic plates. Shenacanthus instead has prominent 'shoulder armour' made of several large plates that completely encircle its body. This feature, thought to be exclusive to placoderms, provides a strong hint that the first cartilaginous fishes were armoured, similar to placoderms.
'Only 20 years ago it was still believed that sharks are primitive and other jawed fish evolved from a shark-like archetype. Now with the discovery of Shenacanthus, we can finally make certain that the opposite is true' said Prof. ZHU You'an.
Image by ZHANG Heming ( If only all reconstructions were as superbly rendered as this one is. It is a work of art - Don)
Text: english.cas.cn/research/highlight/palaeontology/202209/t20220928_320888.shtml
Editor: LI Yuan | Sep 29, 2022
Long (2024) has a delightful background story to the above:
The oldest early shark known from an almost complete body fossil is Shenacanthus from Chongquing, South China, which lived around 437 Mya. Its discovery was quite serendipitous. Three young Chinese palaeontologists were messing around play-fighting when one kung-fu kicked another into a roadside cliff-face. Some rocks came tumbling down, and one split to reveal a hidden treasure of a spectacular fossil fish inside it. This turned out to be the oldest known complete fossil fish with jaws ever found! They couldn't believe their luck.
With further digging they found a layer rich in complete skeletons of early fishes including Shenacanthus. It was a small fish, about an inch long, with bony plates covering the top of the skull and enveloping its chest area. It has pectoral fins without spines yet bears a stout dorsal fin spine similar to that of the acanthodians.
Jaws with teeth have not been found on the specimen, so teeth might well have been absent. Strange tooth whorls that belong to a stem shark called Qianodus were also found in rock layers of this age in China. They are not the same as shark teeth with sharp-pointed cusps - these would not develop in sharks until the Devonian period.
Shenacanthus might bridge the gap between sharks and another early jawed fish group called placoderms ('plated skin'). Placoderms appear in the Early Silurian at exactly the same time.
I feel compelled to add here that John Long's book, 'The Secret History of Sharks' should have a prominent place on every enthusiast's bookshelf. It is superbly written, the author is a leading researcher and publisher, a world-leading palaeontologist, and for decades has been on the cutting edge of shark research. He is Strategic Professor in Palaeontology at Flinders University in Adelaide, South Australia. I found the book un-put-downable - Don
Platystoma plebium (above) is a fossil gastropod, or snail, that lived in the Silurian period about 400 million years ago. It has been found in the Waldron Shale Formation of St. Paul, Indiana, and is often encrusted with tubeworms.
Gastropods have been around since the Late Cambrian period.
There are 611 known families of gastropods, with 202 families being extinct and only appearing in the fossil record.
The class Gastropoda has the second largest number of named species, after insects.
Photo: Don Hitchcock 2015
Provenance: Indiana
Source: Muséum de Toulouse
Dalmanites Limulurus is a trilobite, a member of the Order Phacopida, Family Dalmanitidae from the Silurian Clinton Group, Rochester Formation deposits, near Rochester, New York.
The species name is derived from perceived similarities in appearance to the modern-day horseshoe crab Limulus.
Size: Circa 50 mm.
Photo: Don Hitchcock 2015
Provenance: New York
Source: Muséum de Toulouse
Text: Adapted from www.fossilmuseum.net
The Tumblagooda Sandstone
The track was possibly made by a eurypterid, which are often called 'sea scorpions', about one metre in length.
This Silurian sandstone exposed in the Murchison River Gorge, Western Australia, is called the Tumblagooda Sandstone. When it was deposited 430 million years ago by fast-flowing rivers and swirling wind, plants like liverworts and mosses had only just started to take root on land. Higher plants, like trees, ferns or grasses, had not evolved.
There was little to calm the powerful and relentless erosive forces of the wind, rain, and Sun. The air would have been filled with swirling, fine dust as sandstorms swept across the bare land. Into such a hostile environment animals left the earliest evidence of their arrival — footprints on the sands of time.
Preserving a footprint for 430 million years As you can imagine, this is not a simple thing to do. The way the tracks are preserved suggests that these giant arthropods were walking on the land after leaving the water. Their footprints were preserved by sandstorms dropping fine, dry sand onto the wet sand surfaces across which the animals had been walking,
Such preservation could only happen on land as the sun blazed down and as the wind spread a gentle cloak of dust over the little footprints, hiding them from the light of day and preserving them for almost half a billion years.
Eventually the wind, water, sun and time conspired to release them from their almost timeless cover. In this specimen different sized arthropods walked along the edge of a pool of water as it dried up. This is shown by the parallel lines which represent strands left as the water receded. Perhaps the animals were feeding on debris left at the water's edge.
Age: Lower Silurian, 430 Mya
Findspot: Murchison River Gorge, Western Australia
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
The eurypterid Eurypterus remipes, a 'sea scorpion'. from Passage Gulf, Herkimer County, New York, USA.
Age: 410 Mya, Upper Silurian
Findspot: Passage Gulf, Herkimer County, New York, USA
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
The euthycarcinoid, Kalbarria brimmellae
Age: Lower Silurian, 430 Mya
Findspot: Murchison River Gorge, Western Australia
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Eurypterus lacustris
Eurypterus is an extinct genus of eurypterid, a group of organisms commonly called 'sea scorpions'. The genus lived during the Silurian period, from around 432 to 418 million years ago. Eurypterus is by far the most well-studied and well-known eurypterid. Eurypterus fossil specimens probably represent more than 95% of all known eurypterid specimens.
There are fifteen species belonging to the genus Eurypterus , the most common of which is Eurypterus remipes, the first eurypterid fossil discovered and the state fossil of New York.
Members of Eurypterus averaged at about 13 to 23 cm in length, but the largest individual discovered was estimated to be 60 cm long. They all possessed spine-bearing appendages and a large paddle they used for swimming. They were generalist species, equally likely to engage in predation or scavenging.
Photo: Don Hitchcock 2015
Provenance: Buffalo, New York
Source: Muséum de Toulouse
Text: Adapted from Wikipedia
Cyathophyllum caespitosum
Cyathophyllum caespitosum is a species of extinct coral from the order Tabulata, which existed primarily in the Silurian and Devonian periods.
The species is found as a fossil in marine sedimentary rocks, with notable fossils located in regions of what are now Europe, North America, and parts of Asia.
Cyathophyllum caespitosum typically formed bushy or mound-like colonies, often encrusting the seabed or forming dense clumps. These colonies would have a characteristic irregular, branching structure. The corallites, which are the skeletal cups that house the polyps, were generally small but distinct, with a well-developed septal arrangement (radial partitions inside the corallite). The polyps within these corallites were likely small and colonial.
The skeleton of this species is composed of calcium carbonate (CaCO3), forming a rigid structure typical of tabulate corals. The surface of the coral often showed growth in a lamellar or layered fashion.
Cyathophyllum caespitosum lived in shallow marine environments, likely forming part of the reef ecosystem. As a colonial coral, it would have been a filter feeder, relying on plankton and organic matter suspended in the water column. Like many corals, it may have had symbiotic relationships with photosynthetic organisms, such as zooxanthellae, in clearer, shallow waters with adequate sunlight.
The fossilised remains of Cyathophyllum caespitosum provide valuable insights into the marine environments and ecological systems of the Silurian and Devonian periods.
Its fossil form, particularly the structure of the colonies and corallites, is used in the study of ancient coral communities and can help palaeontologists understand the diversity and distribution of ancient reef-building organisms.
In summary,Cyathophyllum caespitosum is an extinct, tabulate coral species that formed bushy or mound-like colonies in shallow marine environments. It played a role in reef ecosystems during the Silurian and Devonian periods, and its fossil remains are important for understanding ancient coral communities and marine life of the Palaeozoic.
Photo: Don Hitchcock 2015
Provenance: Huccorgne, Liege, Belgium
Source: Muséum de Toulouse
Text: Various sources
Scyphocrinites elegans is a crinoid that lived from the late Silurian to early Devonian (430 - 415 million years ago). Its fossils have been found in Asia, North America, Europe, and Africa.
Scyphocrinites elegans is an extinct type of echinoderm related to sea stars and sea urchins. Crinoids like Scyphocrinites elegans are often referred to as 'sea lilies' due to their plant-like appearance, though they are marine animals.
Like most crinoids, Scyphocrinites elegans had a long, stalk-like structure that anchored it to the seafloor. The body was composed of a cup-shaped 'calyx' at the top of the stalk, which housed the mouth and digestive organs. From the calyx, the animal would have extended feathery, branched arms that were used to capture food from the water column, typically plankton and small particles. The size of Scyphocrinites elegans could vary, but crinoids in general range from a few centimetres to several metres in height, depending on the species.
One of the key features of Scyphocrinites elegans was its elegant and elaborate arrangement of arms, which were often finely branched. The individual 'plates' that made up its calyx were well-defined, and it had a relatively ornate appearance, hence the species name 'elegans'. The arms and calyx would have been adapted for filter feeding in the currents.
Scyphocrinites elegans would have lived in shallow marine environments, where it anchored itself to the substrate and relied on the movement of water to bring it food. Its filter-feeding behaviour would have been typical for crinoids, as they trap microscopic organisms suspended in the water using their arms, which are lined with tube-like structures called pinnules.
Text: Various sources
Upper photo:
Photo: Don Hitchcock 2015
Provenance: Near Merzouga, a small village in southeastern Morocco.
Source: Muséum de Toulouse
Lower photo:
Silurian, 416 million years old
Origin: Morocco, Erfoud. Exhibited at the Musée des Confluences, in Lyon
Photo: Vassil
Permission: Creative Commons CC0 1.0 Universal Public Domain Dedication
A mollweide map of Earth 390 million years ago, during the middle Devonian, overlaid by a black outline of present-day countries in their respective locations.
The Devonian was a geologic period that lasted from 419.2 to 358.9 million years ago, and was part of the Paleozoic era. It was a time of significant evolutionary advancements for fish, and is known as the 'Age of Fishes'.
Other notable events during the Devonian include:
The appearance of seed plants and terrestrial tetrapods
The onset of the Late Palaeozoic Ice Age
The first vertebrates moved onto land
The collision of the continents of Laurentia and Baltica, which formed the Caledonian Mountains
Much of the Northern Hemisphere was covered by Panthalassa, a huge 'world ocean'. Much of the land was covered by shallow seas, where tropical reef organisms lived.
Large areas of shallow sea in North America, central Asia, and Australia became basins where rock salt, gypsum, and other minerals precipitated.
A mass extinction event caused by lack of oxygen occurred near the end of the Devonian.
This lack of oxygen prohibited decay and allowed the preservation of organic matter. This, combined with the ability of porous reef rocks to hold oil, has led to Devonian rocks being an important source of oil, especially in Canada and the United States.
The Devonian period is named for the red-coloured sediments generated when North America collided with Europe. These rocks were first studied in Devon, England.
Text above: Various sources
Image: Scotese, Christopher R.; Vérard, Christian; Burgener, Landon; Elling, Reece P.; Kocsis, Ádám T
Permission: Creative Commons Attribution 4.0 International, via Wikipedia
Text on map added by Don Hitchcock
Urasterella asperula, Devonian Age, Hunsrück Slate, Bundenbach, Germany.
This exceptional specimen appears to be pyritised, which enhances its natural beauty, and leads to very detailed fossils.
Hunsrück is one of the few marine Devonian Lagerstätte having soft tissue preservation, and in many cases fossils are coated by a pyritic surface layer. Preservation of soft tissues as fossils normally requires rapid burial in an anoxic (i.e., with little or no oxygen) sedimentary layer where the decomposition of the organic matter is significantly slowed. The pyritisation found in Bundenbach fossils facilitated preservation and enhanced the inherent beauty of the fossils.
Pyritisation is rare in the fossil record, and is believed to require not only rapid burial, but burial in sediments both low in organic matter, and high in concentrations of sulphur and iron. Such pyritisation is also prevalent in the lower Cambrian fossils from the Maotianshan shales of Chengjiang, China, the oldest Konservat Lagerstätte of Cambrian time.
The best localities for exceptionally preserved fossils are in the communities of Bundenbach and Gemünden. The slates were widely quarried in the past, mainly for roofing tiles from small pits, of which over 600 are known. Today, only a single quarry remains open in the main fossiliferous region of Bundenbach. There are also areas of the Hunsrück Slates where fossils are neither well preserved, nor pyritised, indicating that there also existed environments with shallow and fully oxygenated water.
( Note also the extreme care and ultimate professionalism of the curators of the museum in presenting the fossil in the best possible way. This is what dedication, artistry, and a deep knowledge of difficult procedures can produce - Don )
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Adapted from Wikipedia
Dicranurus monstrosus, Lower Devonian
Dicranurus (Greek, 'dikranon', a pitchfork, and 'oura', tail) is a genus of Lower to Middle Devonian odontopleurid trilobites that lived in a shallow sea that lay between Euramerica and Gondwana, corresponding to modern-day Oklahoma and New York, and Morocco, respectively. Their bodies averaged about 25 mm or so, in length, though their large spines made them at least 51 mm in total length. It is speculated that such tremendous spines hampered the ability of predators, such as arthrodire placoderms (armoured, jawed fishes), to attack them, as well as to help prevent them from sinking into the soft mud of their environment. Dicranurus trilobites are distinguished from other odontopleurids by the pair of large, curled, horn-like spines that emanate from behind the glabellum. The genus name refers to these distinctive horns.
Findspot: Djebel Oufaten, Morocco
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Adapted from Wikipedia
Ceratarges armatus, Middle Devonian.
Ceratarges armatus is an extremely ornamented member of the trilobites' Lichid family. These trilobites have adapted for extreme defensiveness. Their long genal appendages afford them controlled escape from the water column, and they used them to sink to the ocean floor mimicking falling organic debris to escape predators. The stalked eyes, which evolved several separate times in the trilobite lineage, afforded greater lookout ability through they still maintain their compound lenses.
( The eyestalks are quite thick in relation to their length in this specimen - Don )
Findspot: Djebel Marrachib, Morocco
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Adapted from astrogallery.com
Generalised anatomy of a brachiopod dissected down the symmetrical plane.
Source and text: Baird (2012)
Brachiopods, Devonian.
See key above for identification numbers.
• 18 and 30 Rhynxhonella sp., Rhines, Belgium
• 19 Uncites gryphus, Paffrath, Germany
• 20 Atrypa angulosa, Gerolstein, Germany
• 21 Atrypa reticularis, Gerolstein, Germany
• 22 and 31 Cyrtospirifer Verneuilli, Feluy, Belgium
• 23 Atrypa spinosa, Namur, Belgium
• 24 and 29 Hypothyridina Cuboides, Visé, Belgium
• 25 and 27 Schizophoria striulatus, Visé, Belgium
• 26 Brachiopoda sp., Eifel, Germany
• 28 and 33 Stringocephalus burtini, Paffrath, Germany
• 32 Spirifer aperturatus, Paffrath, Germany
• 34 Spirifer lonsdalii, Haute-Garonne, France
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Brachiopods, Devonian.
See key at left for identification numbers.
• 7 and 8 Rhynchonella pleurodon, Visé, Belgium
• 9 and 14 Spirifer striatus (sic), Belgium
• 10 Choristites mosquensis, Miatchkowa, Russia
• 11 Terebratula sacculus, Germany
• 12 Spirifer rotundatus, Germany
• 13 Pugnax pugnus, Witten, Germany
Brachiopods
See image above for identification.
Photo and rephotography: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Archaeocidaris brownwoodensis
Archaeocidaris is an extinct genus of echinoid that lived from the Late Devonian to the Late Permian. Its remains have been found in Africa, Europe, and North America.
Findspot: Texas USA
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Wikipedia
Hapalocrinus frechi
Devonian period
Palm Tree Crinoid
370 - 360 million years ago
Like most crinoids, Hapalocrinus frechi had a stalk that anchored it to the seafloor, from which branched a cup-shaped body known as the calyx. The calyx housed the mouth and digestive organs. Extending from the calyx were the arms, which were equipped with feathery structures used for feeding and capturing plankton.
Hapalocrinus frechi was relatively large for a crinoid, with the stalk typically reaching a length of several metres.
The arms of Hapalocrinus frechi were long and branched, characteristic of crinoids, and equipped with pinnules (smaller feathery structures) for filtering food from the water.
The stalk was composed of calcareous ossicles (small calcium carbonate plates) that helped provide rigidity and stability. The structure of the stalk allowed the animal to stay anchored while it extended its arms to feed on plankton.
Hapalocrinus frechi lived in shallow to moderately deep marine environments, often in areas with strong currents where plankton and other food sources were abundant. The crinoid was probably a filter feeder, using its arms to capture microscopic organisms from the water.
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Various sources
The most severe of the Late Devonian ocean anoxia events was the Kellwasser Event.
The Late Devonian extinction consisted of several extinction events in the Late Devonian Epoch, which collectively represent one of the five largest mass extinction events in the history of life on Earth. The term primarily refers to a major extinction, the Kellwasser event, also known as the Frasnian-Famennian extinction, which occurred around 372 million years ago, at the boundary between the Frasnian age and the Famennian age, the last age in the Devonian Period.
Image: Sarah K. Carmichael, Johnny A. Waters, Peter Königshof, Thomas J. Suttner, Erika Kido.
Source: www.sciencedirect.com/science/article/abs/pii/S0921818118306258
Cladoselache
A modern restoration of the Devonian Chondrichthyan Cladoselache fyleri
Photo and text: EvolutionIncarnate
Permission: Creative Commons Attribution-Share Alike 4.0 International licence
Cladoselache is an extinct genus of shark-like chondrichthyan (cartilaginous fish) from the Late Devonian (Famennian) of North America. It was similar in body shape to modern lamnid sharks (such as mako sharks and the great white shark), but was not closely related to lamnids or to any other modern (selachian) shark. As an early chondrichthyan, it had yet to evolve traits of modern sharks such as accelerated tooth replacement, a loose jaw suspension, enameloid teeth, and possibly claspers.
Some 20th century studies considered Cladoselache to be a basal (early-diverging) member of Elasmobranchii, the fork of cartilaginous fish which leads to modern sharks and rays.[1] More recent studies have identified distinctive traits of the chondrocranium (cartilaginous braincase), dorsal fin spines, and pectoral fin bases.[2][3][4] These newly identified features support a close relationship to symmoriiforms, a small group of bizarre chondrichthyans such as the bristle-spined Stethacanthus. Cladoselache and symmoriiforms may be more closely related to chimaeras (a modern group of unusual deep-sea fish) than to true sharks and rays.
Growing to several metres in length, Cladoselache is considered to have been a fast-moving and fairly agile marine predator due to its streamlined body and deeply forked tail. From both an anatomical and historical perspective, is one of the best known of the early chondrichthyans in part due to an abundance of well-preserved fossils, discovered in the Cleveland Shale on the south shore of Lake Erie. In addition to the cartilaginous skeleton, the fossils were so well preserved that they included traces of skin, muscle fibres, and internal organs, such as the kidneys.
The anatomy of Cladoselache shows a mixture of derived and ancestral characteristics. The skeleton is composed of tessellated cartilage, a complex tissue unique to chondrichthyans. Tessellated cartilage combines flexible cartilage fibers with a loose mosaic of irregular calcified plates, known as tesserae.
The head shape of Cladoselache shares some similarities with modern frilled sharks, while its overall streamlined body shape is reminiscent of mackerel sharks in the family Lamnidae, which likely had a similar ecology. The largest undisputed skeleton of Cladoselache was about 2.0 metres in length, though many specimens were much smaller.
Photo: Don Hitchcock 2015
Source: Facsimile, resin cast, Muséum de Toulouse
Provenance: Cleveland, Ohio
Text: Wikipedia
Skeletal diagram of Cladoselache fyleri in top-down view (top) side on (centre) and from below (bottom).
Photo and text: EvolutionIncarnate
Permission: Creative Commons Attribution-Share Alike 4.0 International licence
Dunkleostus terrelli was one of the largest species of placoderm and also one of the largest predators of the Devonian, growing to the size of modern Great White Sharks (6 m). It has become famous for its impressive set of jaws that also sported an equally impressive bite.
The bite force of a fully grown Dunkleostus terrelli is estimated to be between 4400 N and 7400 N. This is one of the strongest bites among all fish, both living and extinct. It even rivals the modern record holders, the crocodilians.
Dunkleostus could also quickly open and close its jaws, creating suction, like modern-day suction feeders.
Photo: Don Hitchcock 2015
Source: Natural History Museum of Vienna
Text: Wikipedia and commondescentpodcast.com/2018/02/25/episode-29-placoderms-the-armored-fish/
A good rendering of Dunkleostus terrelli on the prowl.
Photo: https://thedaily.case.edu/tag/devonian-period/
Latimeria chalumnae, a Coelacanth, often called a living fossil.
The oldest known Coelacanth fossils date back more than 410 million years, in the Devonian. Coelacanths were thought to have become extinct in the Late Cretaceous, around 66 million years ago, but were discovered living off the coast of South Africa in 1938.
Note that no date was given by the museum for this specimen, but the three dimensionality and the detail is of such high quality that it appears to be a modern catch.
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Earth during the Carboniferous, circa 330 million years ago
A mollweide (equal-area) projection map of Earth 330 million years ago, overlain by a black outline of present-day countries in their respective locations.
Image: Scotese, Christopher R.; Vérard, Christian; Burgener, Landon; Elling, Reece P.; Kocsis, Ádám T
Permission: Creative Commons Attribution 4.0 International, via Wikipedia
Text on map added by Don Hitchcock
Hadronector donbairdi
A thickset Coelacanth from the lower Carboniferous. The small gape to the mouth and tiny teeth show that Hadronector donbairdi preyed upon small food items.
The Bear Gulch Limestone in Montana from which this specimen comes is a deposit of some 70 square km in extent and 30 m in depth that has been a source of one of the most diverse assemblages of fossil fish ever found, with some 110 species having been described over the past 30 years. Most were new to science, and provided a unique view of the marine Coelacanth environment of Mississippian times. Fine preservation of both fish and invertebrates is a hallmark of these deposits, presumably due to an anoxic depositional environment.
Findspot: Montana USA
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: www.fossilmall.com
Platycrinites brevinodus (above) and Macrocrinus mundulus with anal tube preserved (below)
These are listed as being from Crawfordsville, and thus are probably from the famous Witherspoon crinoid quarry near Crawfordsville, Indiana.
Crinoids from the Carboniferous Ramp Creek Limestone were likely buried in sediment from nearby deltas during storms. The resulting siltstone deposits are soft enough that fossils can be extracted in exquisite, three-dimensional relief.
Findspot: Crawfordsville, Indiana, USA
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: www.fossilera.com
Michelinia favosa
A colonial coral from the Carboniferous.
Michelinia favosa formed large, interconnected colonies composed of multiple polyps. These polyps were small, but the colonies could grow quite large. Favosa means honeycomb-like.
The colony's structure of calcium carbonate displays a pattern of small, hexagonal or round pits. These pits, or 'favosites', are the individual living chambers of the polyps. They were typically arranged in regular, honeycomb-like patterns.
The skeletal structure of M. favosa was made of calcium carbonate, a common feature of coral skeletons.
Findspot: Tournai, Belgium
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Various sources
Cockroach, Blattoptera
Blattoptera, or proto-cockroaches is a group of 'roachid' fossil insects that are related to termites, mantises and cockroaches.
Insects reached their largest sizes during the Carboniferous Period, when some of the earliest flying insects grew as large as present-day hawks.
The air was hot and humid during the Carboniferous Period, with vast swampy rainforests covering much of the land. This made it the perfect environment for early insects to grow and thrive. Despite the presence of predators, arthropods were able to colonise the land in many different forms, including large proto-cockroaches.
Findspot: Ceará, Araripe, Brazil
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Adapted from Wikipedia and owlcation.com
Apparent mistaken identity
This life size model is displayed at the NHMV and identified as the world's largest spider, Megarachne servinei, and as being from the Carboniferous period, 320 Mya.
The museum card reads, in part:
The body length of Megarachne servinei is more than 35 cm and its total length is 50 cm. It lived 320 million years ago in the Carboniferous Tropical swamps of today's Argentina. The extraordinary size resulted from the high oxygen content of the atmosphere during the Carboniferous. Megarachne preyed on smaller arthropods and on the many amphibians of the swamps.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
This is one of the fossils associated with the reconstruction of the model above.
Photo: Don Hitchcock 2015
Source: Natural History Museum of Vienna
However, Seldon et al. (2005) present evidence that the fossils associated with this model are actually members of the Eurypterida or sea scorpions group.
Sea scorpions include the largest marine predators to have ever arisen in the fossil record, including one species thought to have been more than 2.5 metres long, Jaekelopterus rhenaniae. Some have four pairs of walking legs, one pair of paddles, and one pair of claws.
Seldon et al. (2005) write:
The original interpretation of Megarachne as a spider was based on the general shape of the carapace and position of the eye tubercle, interpretation of the anteromedian protrusion of the carapace with its median ridge as a pair of spatulate chelicerae, and the circular structure posterior to the first tergite as the abdomen.
Curved lines on the X-radiographs were interpreted as structures hidden in the matrix, for example, cheliceral fangs, sternum, labium and coxae. Some difficulties with the spider interpretation were noted by Hünicken: the unusual cuticular ornamentation, the suture dividing the carapace into anterior and posterior areas, and the spatulate chelicerae are all unknown in any other spider.
In this new study, these morphological features are interpreted differently and in comparison with other giant chelicerates of the Carboniferous Period. Megarachne is not a spider, but a giant eurypterid akin to Woodwardopterus, as in Kjellesvig-Waering (1959).
Image at left: Pterygotus abelov hunting the early fish Birkenia, from the middle Silurian.
Artwork: ABelov2014
Permission: Creative Commons Attribution-Share Alike 3.0 Unported licence
Hypothetical reconstruction of Megarachne based on features of the holotype and second specimen together with Woodwardopterus - metasoma (posterior), telson (sting) - and comparison with Cyrtoctenus (metasoma, telson).
Dashed lines show anatomy reconstructed without direct evidence; chelicerae and palps not known.
Total length circa 54 cm.
Photo and text: Seldon et al. (2005)
Earth during the Permian, circa 275 million years ago
A mollweide (equal-area) projection map of Earth 275 million years ago, overlain by a black outline of present-day countries in their respective locations.
Image: Scotese, Christopher R.; Vérard, Christian; Burgener, Landon; Elling, Reece P.; Kocsis, Ádám T
Permission: Creative Commons Attribution 4.0 International, via Wikipedia
Text on map added by Don Hitchcock
The supercontinent Pangaea and the Permian period, 299-252 million years ago
The position of the continents and oceans is constantly changing - violent earthquakes and volcanoes on the edges of the tectonic plates prove that continental drift is still reshaping the earth today. In the Permian period, almost all continents were united into one, the supercontinent Pangaea. This led to extreme climate changes. Inland, the balancing influence of the seas was missing. Deserts with a very dry seasonal climate formed there. The ancestors of mammals were particularly rich in species during this time.
Sclerocephalus haeuseri, from the Lower Permian.
In the Permian period, the ancestors of today's salamanders and frogs developed. Most species reached their maximum size. A typical example is this armoured amphibian Sclerocephalus, which can reach up to two metres in length and lived in numerous lakes in the former Variscan Mountains, now represented by parts of the Massif Central, the Eifel Mountains, the Cantabrian Mountains and the Bohemian Massif. The animal, covered with bony scales, is at the end of a relatively short feeding sac. Stomach contents show that it mostly fed on the bony fish Paramblypterus. There is also unmistakable evidence of cannibalism.
Skeleton (above) and model (below).
Findspot: Jeckenbach, Rheinland-Pfalz, Germany
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Additional text: Other sources
Sclerocephalus sp.
Sclerocephalus was a salamander-like amphibian that inhabited swamps in present-day Southwest Germany in the Permian.
Findspot: Germany
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Wikipedia
Jimbacrinus bostocki
A crinoid from the Lower Permian.
( clicking on the thumbnail above will give access to a high definition image, 5399 x 5033 pixels - Don )
Abstract from Willink & Kapitany (2024):
Invertebrate macrofossils are superbly preserved in slabs of calcareous silty sandstone exposed in the bed of the Gascoyne River just west of Gascoyne Junction, Western Australia. Based on regional mapping, these rocks have been assigned to the shallow marine Cundlego Formation, which has been dated to the Early Permian. Many of the slabs have preserved the cladid, inadunate crinoid Jimbacrinus bostocki in large numbers, with densities of 150 individuals or more per square metre. Articulated crowns with complete or partial stems attached are often haphazardly aggregated in pods. Details on the morphology of Jimbacrinus bostocki are provided, particularly on juveniles which have cirriferous stems.
Adult stems lack any obvious holdfast and are acutely geniculate below the calyx before being preferentially directed linearly in the homocrinid (E–BC) symmetry plane in the E ray direction. Crowns are commonly preserved with their arms arranged in a protective manner, also referred to as the ‘trauma’ posture. It is inferred that such individuals were likely transported alive by storm induced turbidity currents from a feeding position on a marine shelf to deeper, possibly more anoxic, waters, often accumulating en masse in syndepositional lows such as swales.
They were subsequently smothered by sediment and rapidly buried. These fossiliferous deposits are interpreted as an 'obrution' Lagerstätte. Using taphonomic and functional morphology analysis, possible options for the feeding posture of J. bostocki are proposed. Because of its advanced arm morphology comprising mainly oblique muscular articulations between brachials, the question whether adults were motile, rather than sessile, is addressed.
Findspot: Gascoyne River just west of Gascoyne Junction, Western Australia
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Willink & Kapitany (2024)
Morphological attributes of Jimbacrinus bostocki. A, WAM 2023.53. B–D, WAM 2023.54: anterior, posterior, oral and aboral views of calyx with prox- imal arm segments and anal pyramid attached.
Photo and text: Willink & Kapitany (2024)
Sclerocephalus haeuseri, from the Lower Permian.
Life size model.
Findspot: Jeckenbach, Rheinland-Pfalz, Germany
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
A life restoration of a male Diictodon feliceps, which translates as 'Cat-faced burrower with two weasel teeth'.
Diictodon is an extinct genus of pylaecephalid dicynodont that lived during the Late Permian period, approximately 255 million years ago. Roughly half of all Permian vertebrate specimens found in South Africa are those of Diictodon. This small herbivorous Diictodon feliceps, about the size of a groundhog, was one of the most successful synapsids in the Permian period.
Diictodon had disproportionally large heads that ended in a horny beak. There is a clear distinction between specimens having canine tusks and those lacking them, as tusked specimens are generally larger and more likely to develop a pineal boss. This probably reflects sexual dimorphism, with the tusked sex almost certainly being the male.
In many specimens the rim of the pineal foramen, normally formed by the preparietal
and parietal bones, is swollen into a bony boss. This boss, when present, varies in degree
of development from a thin elevated collar around the foramen to a large mound of bone
that may laterally contact the Ranges formed by the parietals.
The pineal gland is a small endocrine gland in the brain of most vertebrates.
Diictodon had strong arms and legs, as well as 5 sharp claws on each hand, and may have had keen senses of smell and sight. Their gait was similar to the 'high walk' of crocodiles. Their jaws were also simplified, with some of the bones dedicated instead to hearing, considered a key sign of mammalian adaptation. Diictodon also had many adaptations for digging, such as highly developed muscles, a cylindrical body, and wide hands.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Additional text: Sullivan (2000), Wikipedia
Mesosaur, Brazilosaurus sanpauloensis, Upper Permian, 253 Mya. Probably a facsimile.
Fossils of this freshwater reptile have been found in Africa and South America.
Photo: Don Hitchcock 2010
Source and text: Australian Museum Sydney
This is what the 'prehistoric dachshund' Procynosuchus delaharpae might have looked like.
At the end of the Permian around 252 million years ago, the earth's living environment experienced its worst mass extinction. Within a few tens of thousands of years, almost three quarters of land creatures and 90 percent of marine life fell victim to a fatal cascade of volcanic eruptions, greenhouse gases and unstable seas.
But shortly before this geological catastrophe, evolution took another decisive step forward: the ancestors of mammals emerged - amazingly mammal-like reptiles. These therapsids already had fur and, unlike their more primitive relatives, were probably already warm-blooded. You can get up close and personal with these ancestors of mammals in the Korbacher Spalt, a 20-meter-deep and four-meter-high fissure in the limestone of this northern Hessian region filled with fine-grained sediment.
This fissure, which was formed at the end of the Permian period, contains a particularly large number of fossil remains of the globally rare therapsids. Particularly famous is Procynosuchus, which is also nicknamed the 'primeval dachshund' because of its stocky build and short legs. In terms of evolutionary history, it forms a bridge between the reptiles of the Permian period and the mammals that first appeared in the Triassic period. This makes Procynosuchus a real 'missing link' in evolution. The find in the Korbacher Spalt is also the only evidence of this species in the northern hemisphere to date.
Procynosuchus (Greek for 'pre-dog crocodile') is a genus of primitive therapsids within the Cynodontia. Fossils of this 'mammal-like reptile' were found in the Middle and Upper Permian (270 to 251 mya) in South Africa, Zambia and in the Korbach fissure in northern Hesse. The Procynosuchus is sometimes jokingly called the 'Korbach dachshund' because its short legs are reminiscent of a dachshund.
Procynosuchus was about 60 centimetres long and, unlike other therapsids, had adaptations to life in the water, in particular an exceptionally mobile hind body with a laterally flattened tail, which probably allowed swimming similar to that of crocodiles or otters. It is therefore assumed that Procynosuchus lived semi-aquatically, similar to these animals, and fed on fish or other aquatic animals.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Additional text: ww.scinexx.de/dossierartikel/die-korbacher-spalte/ and Wikipedia
Eryops megacephalus, terror of the Permian swamps. This amphibian with an elongated head and a well-built skeleton was a formidable hunter. Submerged, its flat skull revealed only its nostrils and eyes. Its mouth, filled with numerous sharp teeth, seized both “fish” and amphibians passing nearby. Unlike its current descendants with smooth, bare skin, its body was covered in scales.
( Note that although only one eye socket can be clearly seen in this image, there is another in the specimen, nearly hidden by the convexity of the skull - Don )
Some structures in Eryops megacephalus are unlike those in modern forms. The pineal eye, which was much larger than in modern lizards, lay in a distinct socket, while its stalk was housed in a groove in the skull vault. See: Dempster (1934)
Eryops (from the Greek eryein, 'drawn-out' ops, 'face', because most of its skull was in front of its eyes) is a genus of extinct, amphibious temnospondyls. It contains the single species Eryops megacephalus, the fossils of which are found mainly in early Permian (about 295 million years ago) rocks of the Texas Red Beds, located in Archer County, Texas. Fossils have also been found in late Carboniferous period rocks from New Mexico. Several complete skeletons of Eryops have been found in lower Permian rocks, but skull bones and teeth are its most common fossils.
Eryops averaged a little over 1.5 to 2.0 m long and could grow up to 3 m, making them among the largest land animals of their time. Adults weighed between 102 and 222 kg. The skull was proportionately large, being broad and flat and reaching lengths of 60 cm. It had an enormous mouth with many curved teeth, like those of frogs. Its teeth had enamel with a folded pattern, leading to its early classification as a 'labyrinthodont' ('maze toothed'). The shape and cross section of Eryops teeth made them exceptionally strong and resistant to stresses. The palate, or roof of the mouth, contained three pairs of backward-curved fangs, and was covered in backward-pointing bony projections which would have been used to trap slippery prey once caught. This, coupled with the wide gape, suggest an inertial method of feeding, in which the animal would grasp its prey and thrust forward, forcing the prey further back into its mouth.
Eryops was much more strongly built and sturdy than its relatives, and had the most massive and heavily ossified skeleton of all known temnospondyls. The limbs were especially large and strong.
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Wikipedia
Pygopterus humboldti, Permian.
When the tide goes out.....
About 250 million years ago, at the end of the Permian, life almost ended on Earth. About 90 percent of the planet's animal species died out. Nearly all the trees disappeared. This catastrophe is known as the Permian extinction.
The organisms living in Permian seas had already gone through a difficult period. The different continents were coming together into a single large mass, Pangea. This changed the shallow coastal areas, so favourable to the flourishing of Life. Then a major biological crisis marked the end of the period and considerably reduced the diversity of living beings.
Pygopterus is an extinct genus of prehistoric bony fish that lived during the Wuchiapingian to Olenekian ages (late Permian to Early Triassic epochs) in what is now England, Germany (Baden-Württemberg, Saxony-Anhalt), Greenland and Svalbard (Spitsbergen). It is one of the few genera of ray-finned fish known to survive, and cross the Permian-Triassic boundary, despite the effects of the Permian extinction.
Findspot: Thüringen, Germany
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Wikipedia and education.nationalgeographic.org
Earth during the Triassic, circa 225 million years ago
A mollweide (equal-area) projection map of Earth 225 million years ago, overlain by a black outline of present-day countries in their respective locations.
Image: Scotese, Christopher R.; Vérard, Christian; Burgener, Landon; Elling, Reece P.; Kocsis, Ádám T
Permission: Creative Commons Attribution 4.0 International, via Wikipedia
Text on map added by Don Hitchcock
Animal bones let alone entire skeletons are rarely found in the layers of the Bunter sandstone. Nevertheless, the animals from this period have left us traces of life, as was the case in Rotfelden near Calw. This site is one of the richest in fossils in the Bunter sandstone and was the scene of a 'dinosaur meeting' 250 million years ago, in the Lower Triassic.
A river had flooded a large area, which then dried up again. Numerous animals left their footprints in the wet mud, which soon dried out and became rock-hard under the scorching power of the sun. The next flood then filled the footprints with sediment. The five-fingered track of the hand-held animal has long been known, but the animal itself has only recently been discovered: it is a rauisuchier, a relative of the crocodiles - probably Arizonasaurus.
In the coarse-grained Bunter sandstone, bones normally dissolve completely when water seeps in. This makes the fossil find from 1967 in the quarry near Rotfelden all the more fascinating: a wonderful skull of the armored amphibian Eocyclotosateus, coloured violet by the mineral vivianite.
Vivianite (Fe 3(PO4)2 .8H2O) is a hydrated iron(II) phosphate mineral found in a number of geological environments. Small amounts of manganese Mn2+, magnesium Mg2+, and calcium Ca2+ may substitute for iron Fe2+ in its structure. Pure vivianite is colourless, but the mineral oxidises very easily, changing the colour, and it is usually found as deep blue to deep bluish green prismatic to flattened crystals. Vivianite crystals are often found inside fossil shells, such as those of bivalves and gastropods, or attached to fossil bone. Vivianite can also appear on the iron coffins or on the corpses of humans as a result of a chemical reaction of the decomposing body with the iron enclosure.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Additional text: Various sources, including Wikipedia
Land vertebrates
Remains of land vertebrates are very rare in the Bunter Sandstone, the Lower Triassic. Usually they are just individual bones that have been embedded in river deposits. The individual bones have usually been worn down by long transport in rivers. More robust bones such as vertebrae or parts of skulls have less 'transport damage' than fine bones, which are often completely destroyed. The purple colour of the fossils is due to the mineral vivianite, which was formed after deposition.
Proto-Frog, Triadobatrachus massinoti, facsimile, 251 Mya - 245 Mya, Lower Triassic
Triadobatrachus is an extinct genus of salientian frog-like amphibians, including only one known species, Triadobatrachus massinoti. It is the oldest member of the frog lineage known, and an excellent example of a transitional fossil. It lived during the Lower Triassic about 250 million years ago, in what is now Madagascar.
Triadobatrachus was 10 cm long, and still retained many primitive characteristics, such as possessing at least 26 vertebrae, where modern frogs have only four to nine. At least 10 of these vertebrae formed a short tail, which the animal may have retained as an adult. It probably swam by kicking its hind legs, although it could not jump, as most modern frogs can. Its skull resembled that of modern frogs, consisting of a latticework of thin bones separated by large openings.
This creature, or a relative, evolved eventually into modern frogs, the earliest example of which is Prosalirus, millions of years later in the Early Jurassic.
Findspot: Madagascar
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Additional text: Wikipedia
Disintegrated skeleton of the Giraffe-necked lizard Tanystropheus antiquus
Upper Buntsandstein Rotfelden near Nagold, the Lower Triassic.
Tanystropheus antiquus is a European species from the latest part of the Early Triassic (late Olenekian stage). Tanystropheus antiquus had a proportionally shorter neck than other Tanystropheus species, so some palaeontologists consider that Tanystropheus antiquus deserves a separate genus, Protanystropheus.
Numerous complete skeletons of small giraffe-necked lizards were found in Rotfelden. These animals, which were barely a metre long, did not yet have a 'giraffe neck'; one such species only developed in late-living relatives such as the giant Tanystropheus conspicuus, which you can see in the 'Fliorama Sea'. The giraffe-necked lizards of the Buntsandstein period probably lived on the banks of small rivers. There are numerous tracks there that are attributed to them.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Additional text: Wikipedia
Vegetation
Towards the end of the Palaeozoic era, the face of the Earth changed dramatically. Tectonic fermentation caused parts of what is now Europe to enter subtropical climate zones. At the same time, intense volcanism caused the carbon dioxide content of the atmosphere to rise. The result was a natural greenhouse effect. Both tectonics and climate change caused many plants to gradually die out. During the Bunter Sandstone period, the Lower Triassic, which marks the beginning of the Mesozoic era (Triassic-Jurassic-Cretaceous), a 'new' plant world emerged.
Neuropteridium - Suggested fern structure: a) Whole plant Neuropteridium elegans, b) Neuropteridium elegans -single pinnula (PIZ 516), c) Neuropteridium voltzii - single pinnula (PIZ 156), d) Scolopendrites sp. fertile frond, e) Neuropteridium voltzii - entire frond, f) Neuropteridium elegans entire frond, Scolopendrites entire fertile organ.
Photo and text: Wachtler (2011), p 76
Bunter Sandstone
The Buntsandstein predominantly consists of sandstone layers of the Lower Triassic series. Sulzbad (Soultz-les-Bains) in Alsace (France) This fern had a short trunk and simply feathered leaves. The feathering and the course of the leaf veins are clearly visible on the fossil on display.
Fern Anomopteris mougeotii
From the Upper Bunter Sandstone (Buntsandstein), Lower Triassic.
The feathered leaves of this fern are often found together with the club mosses Pleuromeia. This indicates that both plants thrived under similar living conditions.
Findspot: Pforzheim-Brötzingen
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Additional text:
Anomopteris mougeotii – Suggested fern structure: a) Whole plant, b) Single bipinnate frond, c) Rachis and aphlebia, d) Fertile pinnae, d) Sterile pinnae.
Photo and text: Wachtler (2011), p 68
Fern Anomopteris mougeotii
From the Upper Bunter Sandstone (Buntsandstein), Lower Triassic.
The feathered leaves of this fern are often found together with the club mosses Pleuromeia. This indicates that both plants thrived under similar living conditions.
Findspot: Pforzheim-Brötzingen
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Pleuromeia sternbergii, a club moss.
Left, complete specimen. Right, close up.
The specimen consists of a longitudinal break through the trunk
Upper Bunter Sandstone (Buntsandstein), Lower Triassic.
Club mosses are now usually low evergreen herbs with needlelike or scalelike leaves. Many species have conelike clusters of small leaves (strobili), each with a kidney-shaped spore capsule at its base. The plants are homosporous, meaning that they produce just one kind of spore. They have terrestrial or subterranean gametophytes that vary in size and shape depending on the genera. In some species, including nearly all those of the north temperate zone, the subterranean gametophyte is dependent upon an associated fungus for continued growth. This sexual phase alternates in the life cycle with the spore-producing plant, the sporophyte, which is aboveground and is formed following fertilisation.
However, in ancient times, clubmosses were particularly diverse in form: the spectrum ranged from small herbaceous species that resembled today's clubmosses to 40 metre high trees with richly branched, lush crowns. In addition to typical spore-dispersing forms, there were also those whose spores remained on the mother plant and formed a few cells there, including an egg cell that was then fertilised, almost like real seed plants.
Pleuromeia is a typical plant of the Bunter Sandstone, which probably grew near water as a pioneer plant. At the tip of the unbranched shoot was a single spore cone. The small leaves are an adaptation to the dry, hot climate. They reduce evaporation.
Spore plants: Spores are cells with an extremely resistant cell wall. They facilitate plant dispersal by wind. During the transition from water to land life, the development of spores played a major role, as they enabled early land plants to spread quickly. The great era of spore plants - these include mosses, club mosses, horsetails and ferns - was the Palaeozoic period.
The dominance of seed plants began during the Mesozoic era. At the same time, 'modern' families emerged among the spore plants, some of which have survived to this day.
Pleuromeia is an extinct genus of lycophytes related to modern quillworts (Isoetes). Pleuromeia dominated vegetation during the Early Triassic all over Eurasia and elsewhere, in the aftermath of the Permian – Triassic extinction event. During this period it often occurred in monospecific assemblages. Its sedimentary context in monospecific assemblages on immature paleosols, is evidence that it was an opportunistic pioneer plant that grew on mineral soils with little competition. It spread to high latitudes with greenhouse climatic conditions.
Findspot: Dietersweiter near Freudenstadt
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
A pachypleurosaur, Keichousaurus hui, facsimile.
Middle Triassic, 240 Mya, and went extinct at the close of the Triassic.
Keichousaurus (meaning 'Kweichow lizard') is an extinct genus of pachypleurosaurian marine reptile from the Chialingchiang and Falang Formations of China with two known species attributed to the genus: Keichousaurus hui and Keichousaurus yuananensis.
Keichousaurus is among the most common sauropterygian fossils recovered and are often found as nearly complete, articulated skeletons, making them popular among collectors.
Findspot: Guizhou Province, China
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Additional text: Adapted from Wikipedia
Placodus gigas skeleton (cast) from the Upper Muschelkalk (shell-bearing limestone), Steinsfurt near Sinsheim.
Middle Triassic, 240 - 230 Mya.
Among the marine iguanas there were not only fast hunters. The Placodus-toothed lizards were clumsy animals with a rigid torso and weak arms and legs. The round teeth of the common species Placodus are regularly found in the Muschelkalk. With its large, flat teeth it cracked open mussels that it had previously picked out of the sand or rocks with its longer front teeth. This marine iguana had a series of thick bones on its back. In other flat-toothed lizards these bone plates were even more numerous and covered large parts of the torso and belly. This created a turtle-like shell. It is not yet known whether flat-toothed lizards had to go on land to lay their eggs like sea turtles or whether they gave birth to live offspring like many other podded lizards.
Placodus lizards were clumsy animals with a rigid torso and weak arms and legs. The round teeth of the common species Placodus are regularly found in the Muschelkalk limestone. This marine iguana had a series of thick bones on its back. In other Placodus lizards these bone plates were even more numerous and covered large parts of the torso and belly. This created a turtle-like shell. It is not yet known whether Placodus lizards had to go on land to lay their eggs like sea turtles or whether they gave birth to live offspring like many other podded lizards.
The Muschelkalk (shell-bearing limestone) is a sequence of sedimentary rock strata consisting of a sequence of limestone and dolomite beds in the geology of central and western Europe. It has a Middle Triassic (240 to 230 million years) age and forms the middle part of the three-part Germanic Trias (that gives the Triassic its name) lying above the older Buntsandstein and below the younger Keuper.
Findspot: Steinsfurt near Sinsheim
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Skeletal restoration of Tanystropheus antiquus (now referred to its own genus Protanystropheus) from the Middle Triassic of Central Europe, based on Wild (1973: pl. 1) and specimens from the Upper Buntsandstein of the Black Forest, i.e. the Lower Triassic.
Photo: Rupert Wild & Henk Oosterink
Permission: This image was published in an article by Grondboor en Hamer. Made available under the license CC BY 3.0 NL.
Source: commons.wikimedia.org/wiki/File:Tanystropheus_antiquus_skeletal_restoration.jpg
Armoured amphibian Eocyclotosaurus woschmidti skull
Middle Triassic, circa 247 - 242 Mya.
The name Eocyclotosaurus means 'dawn round-eared lizard'. It is characterised as a capitosauroid with a long and slender snout, closed otic fenestra, and small orbits.
Armoured amphibians were usually significantly larger than salamanders and frogs, their modern relatives. Their skulls were armoured all around with thick bone plates. Many also had bony scales on their belly. Most armoured amphibians lived in fresh water and fed on fish, as evidenced by fossil stomach contents. The Eocyclotosaurus, one of the numerous armoured amphibians of the Buntsandstein period, which was up to three metres long, was widespread. It is known not only from the Black Forest, but also from the Vosges of eastern France, England, and western North America.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Additional text: adapted from Wikipedia
Thrinaxodon sp.,
245 - 228 Mya
Thrinaxodon is an extinct genus of cynodonts, including the species T. liorhinus which lived in what are now South Africa and Antarctica during the Late Permian - Early Triassic. Thrinaxodon lived just after the Permian–Triassic mass extinction event, its survival during the extinction may have been due to its burrowing habits.
Similar to other therapsids, Thrinaxodon adopted a semi-sprawling posture, an intermediary form between the sprawling position of basal tetrapods and the more upright posture present in current mammals. Thrinaxodon is prevalent in the fossil record in part because it was one of the few carnivores of its time, and was of a larger size than similar cynodont carnivores.
Thrinaxodon was a small synapsid roughly the size of a fox and possibly covered in hair. The dentition suggests that it was a carnivore, focusing its diet mostly on insects, small herbivores and invertebrates. Their unique secondary palate successfully separated the nasal passages from the rest of the mouth, allowing the Thrinaxodon to continue mastication without interrupting to breathe, an adaptation important for digestion.
Cast in patinated resin.
Findspot: South Africa
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Horseshoe Crab
Tachypleus gigas Syn. Limulus mollucanus
250 Mya/Present, Lower Triassic.
( Note that it is not clear from the Museum's documentatioin whether this is a fossil or a modern example, but given its condition, it is likely a modern example - Don )
For modern horseshoe crabs, their earliest appearance was approximately 250 million years ago during the Early Triassic. Because they have seen little morphological change since then, extant (surviving) forms have been described as 'living fossils'.
Horseshoe crabs are arthropods of the family Limulidae and the only surviving xiphosurans. Despite their name, they are not true crabs or even crustaceans; they are chelicerates, more closely related to arachnids like spiders, ticks, and scorpions. The body of a horseshoe crab is divided into three main parts: the cephalothorax, abdomen, and telson. The largest of these, the cephalothorax, houses most of the animal's eyes, limbs, and internal organs. It is also where the animal gets its name, as its shape somewhat resembles that of a horseshoe.
Only four species of horseshoe crab are extant today. Most are marine, though the mangrove horseshoe crab is often found in brackish water. Additionally, certain extinct species transitioned to living in freshwater. Horseshoe crabs primarily live at the water's bottom but they can swim if needed. In the modern day, their distribution is limited, only found along the east coasts of North America and South Asia.
Merostamata comprises two groups of animals of marine ecosystems, i.e. sea scorpions (Euripterida) and horseshoe crabs (Xiphosura). The sea scorpions are an extinct group of animals, and thus the Merostamata are represented by only the living horseshoe crabs of Xiphosura in the present era. The merostomata is characterised with respiration by book gills, excretion by coxal glands, a prosoma with 6 pairs of appendages of which the first one with chelicerae (to help in capturing food), with the next four appendages used as walking legs, and the last one as a pusher leg. The first pair of ophisthosomal appendages are fused with the genital operculum, and the next five ophisthosomal appendages are modified into booklungs. This group of organisms are much closer to the sea spiders (extinct) and arachnids (Spiders and scorpions) rather than other aquatic crustaceans.
Findspot: Ile de Poulo-Condore, Vietnam
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Adapted from Wikipedia
Additional text: Mohapatra (2020), Miquel (1838)
Phytosaur, Nicrosaurus kapffi
221 - 205 Mya.
Nicrosaurus is an extinct genus of phytosaur reptile existing during the Late Triassic period. Although it looked like a crocodile (and probably lived like the more terrestrial crocodylomorphs), it was not closely related to these creatures, instead being an example of parallel evolution. The main difference between Nicrosaurus (and all other phytosaurs) and modern crocodiles is the position of the nostrils – Nicrosaurus's nostrils, or external nares, were placed directly in front of the forehead, whereas in crocodiles, the nostrils are positioned on the end of the snout.
The genus was named by German paleontologist, Dr. Eberhard Fraas, in 1866, possibly after the Neckar river of southwestern Germany, near which it was found.
Photo: Don Hitchcock 2015
Source: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Text: adapted from Wikipedia
Phytosaur, Nicrosaurus kapffi, as in the above image.
This image shows clearly the position of the nostrils or external nares, in front of the forehead.
The animal was 4m to 6m long.
Photo: Don Hitchcock 2015
Source: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Text: adapted from Wikipedia
Eggs - the road to success
Amphibians - for example, frogs, newts and salamanders - were the first vertebrates to conquer the continents. They laid gelatinous eggs into the water and spent their early life swimming. Even today, this mode of reproduction still makes amphibians dependent on water. Reptiles already solved this problem 300 million years ago. They developed eggs with a protective cover in which embryos were supplied with nutrients. 250 million years ago the climate became arid and the moist environments of the amphibians disappeared. This marked the dawn of the Age of the Reptiles. Already during the Palaeozoic Era, 280 million years ago, a group of 'mammal-like reptiles' split off from the egg-laying reptiles. These were the ancestors of modern mammals. The early mammals were probably oviparous - they laid eggs - as well.
The most beautiful find from Baden-Württemberg is this skeleton of the previously unknown species Nothosaurus jagisteus, which was only discovered in 1992 after blasting in the Berlichingen quarry.
Nothosaurus is the most common marine lizard in the southern German Muschelkalk. However, usually only individual teeth, vertebrae or ribs are found, sometimes entire skulls. The greatest rarities, on the other hand, are connected skeletons, as above.
Findspot: Berlichingen quarry, Baden-Württemberg.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Additional text: Various sources, including Wikipedia
Nothosaurus mirabilis
Skull, the Upper Muschelkalk
Findspot: Crailsheim, Baden-Württemberg.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Nothosaurus mirabilis
Model in life size (about 3 m) based on fossils from the Middle Triassic, Southwest-Germany; Staatliches Museum für Naturkunde Karlsruhe, Germany.
Typical lizards of the Muschelkalk sea are the nothosaurs, to which Nothosaurus mirabilis belongs. They had a long, very flexible neck and clawed front fins. Their teeth with numerous sharp teeth indicate that they are fish eaters.
Source: Model created by Adam Procházka, Baden-Baden, Germany for Staatliches Museum für Naturkunde Karlsruhe, Germany
Photo: H. Zell
Permission: GNU Free Documentation License, Version 1.2 or any later version.
Nothosaurus giganteus
Nothosaurus giganteus lived during the early Triassic period. It was part of the Nothosauria group, which are known for being semi-aquatic creatures with adaptations that suggest they could live in both water and on land.
Nothosaurus giganteus was one of the larger species within its genus, with some estimates suggesting it could reach lengths of up to 6 metres. It had a streamlined body with a long, narrow skull, sharp teeth, and a long tail, features that made it well-suited for an aquatic lifestyle. The long, sharp teeth suggest it may have hunted fish, squid, and other marine animals.
One interesting aspect of Nothosaurus is its limbs. Although its overall body structure suggests it was mostly aquatic, its limbs were adapted for both swimming and moving on land. The forelimbs were paddle-like, ideal for propelling itself through water, while the hind limbs were more suited for walking on land, showing that Nothosaurus was likely able to move between the two environments, much like modern-day seals or sea lions.
It is thought that Nothosaurus lived in coastal environments, where it could dive and hunt in shallow waters, while still being capable of coming onto land to bask in the sun or perhaps lay eggs. Their fossil remains have been found in what is now Europe, with the most significant finds coming from the German Triassic deposits.
Despite their adaptability, Nothosaurus and other similar reptiles went extinct by the late Triassic, probably due to changes in climate and marine environments that affected their prey and overall ecosystems.
Findspot: Heimsheim, Baden-Württemberg, Germany
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Additional text: Various sources
Simosaurus gaillardoti Facsimile
In addition to the slender Nothosaurus, another pinniped lizard lived in the southern German Muschelkalk Sea, the more powerfully built Simosaurus, an animal with a broad skull and thickened teeth that could break open harder shells (crabs or ammonites).
Unlike the paddles of Nothosaurus, it is still very similar to those of land lizards.
Findspot: Middle Triassic, Upper Muschelkalk, Crailsheim, a densely packed, crinoid shell limestone.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Additional text: Various sources, including Wikipedia
Trochite (disc segments) limestone
The stems of sea lilies, some of which are several metres long, are made up of hundreds of individual segments called trochites (from the Greek trochos = wheel or disc)
The decayed remains of the sea lily Encrinus were washed together on the floor of the shallow shell limestone sea during storms. When the turbulent sea calmed down, fine lime mud settled. Some rock banks of the Upper Muschelkalk consist predominantly of trochites ('trochite banks'), popularly known as 'Boniface pennies', or 'Witch money'.
Encrinus liliiformis
If embedded quickly, complete crowns of sea lilies can be preserved.
Upper Muschelkalk, Middle Triassic
Findspot: Zwingelhausen near Backnang
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Trochite limestone
Upper Muschelkalk, Middle Triassic
When viewed from above, each stem segment shows the pattern of a folded star. The ribs and depressions of the stars interlock like 'joints' so that even metre-long stems are stable.
( Note that all of these stem segments shown here in a close up of the image above have been 'rolled' so much before final deposition that their fine detail has been abraded and lost. See the image below for a sense of what they would originally have looked like - Don )
Findspot: Mistlau near Crailsheim.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
This is an excellent plate to demonstrate the patterns of typical stem segments in a star shape, interlocking to create a stable and strong joint between each segment.
1. Metacrinus angulatus(Haeckel) = Saracrinus angulatus (Carpenter, 1884), habitus
2. Pentacrinus Maclearanus (Haeckel) = Endoxocrinus maclearanus (Thomson, 1872), habitus
3. Pentacrinus Wyville-Thomsonii (Haeckel) = Endoxocrinus wyvillethomsoni (Huxley, 1859), habitus
4. Pentacrinus Wyville-Thomsonii (Haeckel) = Endoxocrinus wyvillethomsoni (Jeffreys, 1870), stem ossicle
5. Pentacrinus Wyville-Thomsonii (Haeckel) = Endoxocrinus wyvillethomsoni (Jeffreys, 1870), stem ossicle
6. Pentacrinus Wyville-Thomsonii (Haeckel) = Endoxocrinus wyvillethomsoni (Jeffreys, 1870), stem ossicle
7. Metacrinus angulatus (Haeckel) = Saracrinus angulatus (Carpenter, 1884), stem ossicle
8. Metacrinus angulatus (Haeckel) = Saracrinus angulatus (Carpenter, 1884), stem ossicle
Artwork: Kunstformen der Natur (1904), plate 20: Crinoidea
Permission: Public Domain
Proximal source: Wikipedia
Simosaurus gaillardoti skull.
Upper Muschhelkalk, Middle Triassic.
Rüblingen, Kupferzell, Baden-Württemberg, Germany.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Keichousaurus hui
Middle Triassic
Location: Xingyi, Guizhou Province, China
Keichousaurus is an extinct genus of pachypleurosaurian marine reptile from the Chialingchiang and Falang Formations of China with two known species attributed to the genus: Keichousaurus hui and Keichousaurus yuananensis
The Pachypleurosaurian clade had small heads, long necks, paddle-like limbs, and long, deep tails. The limb girdles are greatly reduced, so it is unlikely these animals could move about on land. The widely spaced peg-like teeth project at the front of the jaws, indicating that these animals fed on fish.
Keichousaurus is among the most common sauropterygian fossils recovered and are often found as nearly complete, articulated skeletons, making them popular among collectors.
Like the fish lizards, the pinnipeds (Sauropterygians) also developed from small land reptiles into swimmers who did not even have to leave the water to lay their eggs: finds of embryos in the womb prove that pinnipeds were viviparous.
On the rigid torso were strong arms and legs that had been transformed into paddles, which were moved up and down in a rowing motion, similar to sea turtles. Pinniped lizards probably preyed on fish. Pinniped lizards include the pachypleurosaurs, which are barely 20 cm long, the nothosaurs, which are up to seven metres long, and the plesiosaurs, which are 25 metres long.
Reptiles usually hatch from eggs. The fact that marine dinosaurs give birth to live animals is an adaptation to their habitat. Reptile young look very similar to their parents. Unlike with amphibians, there is no larval stage.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Additional text: Wikipedia
Barracudasauroides panxianensis
Middle Triassic
Stage : Anisian from 247.2 million years ago until ~242 million years ago
Size and weight : 118 x 62 x 545 cm – 79.4 Kg
Barracudasauroides is a genus of mixosaurid ichthyosaur which lived during the Middle Triassic. Fossils of this genus have been found in Guizhou Province, China. It is known from GMPKU-P-1033, a partial skeleton recovered from the Upper Member of the Guanling Formation of Yangjuan village, Xinmin area; this rock unit dates to the Pelsonian substage of the Anisian stage. It was named by Michael W. Maisch in 2010, and the type species is Barracudasauroides panxianensis.
Findspot: China, Guizhou Province - Guanling Formation
Accession Number: MHNT.PAL.2006.80.6
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Barracudasauroides panxianensis
Middle Triassic
This is a larger image of the above, 8133 x 3145 pixels, stitched together from four individual images.
Findspot: China, Guizhou Province - Guanling Formation
Accession Number: MHNT.PAL.2006.80.6
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Dinosaurs in Swabia - The Middle/Upper Keuper, 233 - 200 Mya, the Upper Triassic. A herd of plateosaurs.
The river is a hive of activity. In the thickets under tall conifers, small mammals seek refuge not only from the heat, but also from nimble predators such as Saltoposuchus. The sturdy, heavily armoured eagle-headed lizards, on the other hand, can search for food in the undergrowth relatively undisturbed. A herd of plateosaurs has also gathered on the bank. Hardly anyone can pose a threat to these large dinosaurs. Perhaps Liliensternus, when he goes on the prowl with his own kind. The nutritious plateosaur eggs, on the other hand, have many interested parties. That is why the parents keep a close eye on them.
Plateosaurus was a bipedal herbivore with a small skull on a long, flexible neck, sharp but plump plant-crushing teeth, powerful hind limbs, short but muscular arms and grasping hands with large claws on three fingers, possibly used for defence and feeding. Unusually for a dinosaur, Plateosaurus showed strong developmental plasticity: instead of having a fairly uniform adult size, fully grown individuals were between 4.8 and 10 metres long and weighed between 600 and 4 000 kilograms. Commonly, the animals lived for at least 12 to 20 years, but the maximum life span is not known.
Photo: Don Hitchcock 2015
Source: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Taeniopteris 228 Mya - 217 Mya, Upper Triassic, is an extinct genus of Mesozoic vascular plant leaves, perhaps representing those of cycads, bennettitaleans, or marattialean ferns.
The form genus is almost certainly a polyphyletic category for infertile leaves of a certain shape ('taeniopterids') which cannot be assigned to specific groups due to a lack of information on cuticle or spore structures.
The leaves are simple, with a strong central vein (rhachis) and an unbroken margin. The central vein leads to nearly perpendicular lateral veins, which may be slightly divided or undivided. The shape of the leaf is variable, but often elongated and smooth-edged.
Taeniopterus leaves are characterised by an entire margin and a midrib with secondary veins that may or may not bifurcate. This artificial group contains leaves that belong to ferns or, mainly, cycadophyte, gymnosperms.
Findspot: Lunz, Austria
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Additional text: Various sources including Wikipedia
Plagiosuchus pustuliferus
Skull, Lower Keuper, Upper Triassic.
Plagiosuchus is an extinct genus of plagiosaurid temnospondyl. It is known from several collections from the Middle Triassic of Germany.
Plagiosuchus has a relatively long skull for a plagiosaurid, approximately as long as it is wide. However, its most defining feature is its greatly enlarged orbit, which forms a massive orbitotemporal fenestra with the loss of several post-orbital bones, including the postfrontal and the postorbital, and the reduction of several others.
Findspot: Eschenau near Veliberg
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Plagiosternum granulosum
Armored amphibian, Plagiosaurian.
Photo of the Skull, Lower Keuper, Upper Triassic.
( Note that much of this specimen has had to be restored from several pieces - Don )
Armoured amphibians were primitive amphibians that were already widespread in the Bunter Sandstone period. In the Keuper period, some of them reached truly gigantic proportions. Despite all the diversity that we now know from the Keuper swamps, externally, most armoured amphibians resembled 'giant newts', elongated, with short legs and a strong tail. However, they were heavily armoured. The large skulls were closed except for the eye and nose openings, the belly side was usually protected by bony scales. Their young (larvae) lived in the water and breathed with gills, the adult amphibians were lung breathers.
The plagiosaurs, which were one to three metres long, were purely aquatic amphibians. With their extremely flattened bodies covered all around with armour plates, they probably lay on the bottom of bodies of water like flatfish. Plagiosaurs were lifelong larvae that breathed with gills throughout their lives, something that also occasionally occurs in modern amphibians. Single bones and skeletons of Gerrothorax and Plagiosuchus were found in large numbers near the motorway near Kupferzell, Baden-Württemberg. Both were found in brackish swamps, while Plagiosternum, very unusual for an amphibian, lived in the shallow sea.
Findspot: Ummenhofen near Obersontheim
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Artwork: ДиБгд
Permission: Creative Commons Attribution-Share Alike 4.0 International license.
Plagiosaurus is an extinct genus of temnospondyl amphibian.
The type and only species is Plagiosaurus depressus, first described by Otto Jaekel in 1914.
Artwork: ДиБгд
Permission: This work has been released into the public domain by its author.
CC0 1.0 Public Domain
Gerrothorax pustuloglomeratus
Armoured amphibian: Plagiosaurian
Skeleton
Lower Keuper, Upper Triassic.
This find is the only complete plagiosaurian skeleton in the world. In ancient times in this region the carcasses often decayed so quickly that only individual bones were deposited.
Findspot: Bauersbach near Kupferzell
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Gerrothorax pustuloglorneratus
Rephotography: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Evolution in Isolation
The shallow Muschelkalk sea in the Germanic Basin had hardly any connections to the neighbouring seas. After the evaporation phase in the Middle Muschelkalk, in which large amounts of rock salt were formed, had passed, an as yet unknown ammonoid species migrated into the Germanic Basin from the southwest.
Cut off from the ocean, a dynamic evolution of the ceratites began, limited to the Muschelkalk sea, with species splits that are evident in noticeable changes to the shells. The ceratites of the Upper Muschelkalk have simplified chamber septa compared to their presumed ancestors. The layers of the Upper Muschelkalk can be finely subdivided based on the evolution of the ceratites.
The Gamma clay horizon in the Upper Muschelkalk contains typical freshwater animals such as leaf-footed crustaceans (Estheria) - a clear expression of an ecological crisis (from the point of view of the marine inhabitants) caused by a period of wetter climate and the resulting increased inflow of fresh water. Marine animals such as the ceratites were on the brink of extinction. The break in the evolutionary process symbolises this crisis in the evolution of the ceratites, which was followed by a renewed development.
The Muschelkalk represents the marine part of the Middle Triassic, when vast areas of Central Europe were flooded for seven million years by a shallow sea. While the global sea level was rising, the Tethys Ocean was transgressing through various gateways over Central Europe.
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Earth during the Jurassic, circa 170 million years ago
A mollweide (equal-area) projection map of Earth 170 million years ago, overlain by a black outline of present-day countries in their respective locations.
Image: Scotese, Christopher R.; Vérard, Christian; Burgener, Landon; Elling, Reece P.; Kocsis, Ádám T
Permission: Creative Commons Attribution 4.0 International, via Wikipedia
Text on map added by Don Hitchcock
Ichthyosaurus communis
183 - 175.6 Mya
Early Jurassic
During the Early Triassic epoch, ichthyosaurs and other ichthyosauromorphs evolved from a group of unidentified land reptiles that returned to the sea, in a development similar to how the mammalian land-dwelling ancestors of modern-day dolphins and whales returned to the sea millions of years later, which they gradually came to resemble in a case of convergent evolution.
Ichthyosaurians were particularly abundant in the Late Triassic and Early Jurassic periods, until they were replaced as the top aquatic predators by another marine reptilian group, the Plesiosauria, in the later Jurassic and Early Cretaceous, though previous views of ichthyosaur decline during this period are probably overstated. Ichthyosaurians diversity declined due to environmental volatility caused by climatic upheavals in the early Late Cretaceous, becoming extinct around the Cenomanian-Turonian boundary approximately 90 million years ago.
Text: Wikipedia
Findspot: Holzmaden Germany
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Stenopterygius quadriscissus , an Ichthyosaur, shown here with a single young.
( clicking on the thumbnail above will give access to a high definition image, 10463 x 3581 pixels - Don )
This ichthyosaur probably died before giving birth. Any remaining foetuses were pressed out from the corpse by gas development as the corpse decayed.
Jurassic, 180 Mya, Holzmaden, Germany.
The Posidonia shale around Holzmaden is famous for its fossils from the Lower Jurassic. One of the first fossil collectors was Duke Carl Eugen of Württemberg in 1749. When Bernhard Hauff uncovered fine, coal-black remnants while preparing an ichthyosaur in 1892, it was the first time that fossil remnants of soft tissue were detected, as a result of the anoxic conditions which obtained at this time in this deposit.
After death this ichthyosaur sank to the sea floor, where anoxic conditions prevented its decay by bacteria and scavengers.
Stenopterygius quadriscissus is a type of ichthyosaur, an extinct marine reptile, that lived in the Lower Jurassic period. The Natural History Museum in Vienna has a well-preserved fossil of a female Stenopterygius quadriscissus giving birth to live young, as shown in the image above.
The body shape was dolphin-like with a small head and narrow flippers.The limbs were fin-like structures. The tail was large and semicircular, with a leathery caudal fin. The dorsal fin was triangular. The skull extended into a beak with large teety. It lived in the open seam hunting fish, cephalopods, and other animals.
It swam in shallow oceans that covered large parts of Europe. It gave birth to live young, which developed internally. Infants were born tail-first to prevent drowning.
Some fossils have been found with the remains of juveniles inside, showing that mothers died in childbirth. Well-preserved fossils have been found in Germany.
The somewhat different saurian Ichthyosaurs were viviparous reptiles - they were no longer able to crawl onto the beaches to lay their eggs in the sand. This required a switch to vivipary, live birth. The female had up to 11 embryos, which were born tail first. Many pregnant ichthyosaurs have been found at the German town Holzmaden. Perhaps this was an area where ichthyosaurs came to give birth. The adaptation to vivipary was probably not perfect, and many females apparently died during pregnancy. Such a high mortality was not an evolutionary drawback as long as the population was maintained with ample offspring.
Ichthyosaurs were deep sea predators, and special features for this role are their huge eyes. These allowed them to see their prey even in the gloominess of deep waters. The animals were exposed to large changes in water pressure during diving. Their eyes were therefore protected by a bony scleral ring. The eye of a 12 metre long ichthyosaur attained a diameter of more than 25 cm, making it the largest eye of all vertebrates. When hunting for prey, they reached speeds of up to 40 km/h, but had to surface for breathing.
The dolphin-like ichthyosaurs were marine reptiles that evolved 245 million years ago and already went extinct before the dinosaurs, about 90 million years ago. The largest reptiles that ever lived in the sea are ichthyosaurs; some species attained a body length of 21 metres. Like whales and dolphins, they evolved from land-dwelling vertebrates. They became perfectly adapted to life in the sea. The ichthyosaur diet consisted mainly of the squid-like belemnites, whose rostra (a bullet-shaped, well preserved diagnostic feature of belemnites) are abundant in the stomach and fossil excrements. Some ichthyosaurs specialised in hard-shelled prey such as ammonites and bivalves. Very large-sized species even preyed on turtles and birds.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Additional text: Various sources
Stenopterygius quadriscissus
Jurassic, 180 Mya.
( clicking on the thumbnail above will give access to a high definition image, 10003 x 4109 pixels - Don )
After death, this ichthyosaur sank to the sea floor, where anoxic conditions prevented its decay by bacteria and scavengers.
Findspot: Holzmaden, Germany
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Dorygnathus banthensis
Jurassic, 180 Mya, Holzmaden, Germany
The teeth reveal this pterosaur with a one metre wingspan to be a fish predator. This specimen is known as the Vienna Exemplar.
Flying pterosaurs were the first vertebrate animals perfectly adapted for flight. They lived between 225 and 65 million years ago, at the same time as the dinosaurs. These reptiles became excellent flyers, predating birds by almost 75 million years. The wing membrane stretched from the highly extended fourth finger down to the thigh. The wide wings were perfect for gliding for long distances on ascending air currents. Some pterosaurs might have undertaken seasonal migrations between continents like modern migratory birds. The largest pterosaur was Quetzalcoatlus from North America with a wing span of 12 metres.
The only known species of the genus Dorygnathus ('Spear Jaw') was of moderate size, measuring up to 1.7 metres in wingspan and weighing about 3 kg. It had an elongated, pointed head, up to 16 cm long, with large eyes, a straight forehead, and a beak armed with enormous, curved, very fine, needle-like teeth that projected far from the closed jaws, alternating with the teeth of the opposite jaw. These were the largest teeth in proportion to the head of any known pterosaur. Four of these large teeth were arranged on each side of the anterior half of the upper jaw, and three on each anterior half of the lower jaw (the tip of which was toothless); the posterior half of the upper jaw was occupied by similar but considerably smaller teeth, and the posterior half of the lower jaw had very small, regular teeth (eight or more per hemijad), which contrasted sharply with the enormous anterior teeth. The total number of teeth was at least 44. Its neck was short, although longer than that of other basal pterosaurs, and it had eight long, robust cervical vertebrae. The body was covered with hair. The sternum was small and triangular. The wings were short and narrow, with a short, robust pteroid bone at the wrist, pointing towards the neck. This bone supported the propatagium, that is, the part of the wing membrane located in front of the arm bones. The first three fingers of the wing were small, with short, very curved claws, the fourth finger joined the fifth finger, which as in all pterosaurs formed the front edge of most of the wing, supporting the main flight membrane. The legs had a tibia shorter than the femur, and had a very elongated fifth finger, oriented to the side, making it quite plausible that this finger supported a flight membrane located between the legs and the tail. The tail was long, rigid except at the more flexible base, and was made up of twenty-seven or twenty-eight vertebrae. It is not known whether the tail ended in a leaf-like extension, as in its close relatives in the genus Rhamphorhynchus.
It lived in the archipelago of Europe at the beginning of the Jurassic, between one hundred and eighty-three and one hundred and eighty-two million years ago. It was an animal which specialised in catching fish, which it caught at the surface of the water while flying low, holding its slippery prey with its needle-like teeth. The young grew very quickly, and when they reached sexual maturity, their growth slowed noticeably. The smallest specimen found of this species already measured a considerable sixty cm of wingspan, which may indicate that the smallest young did not venture into the sea, where the adult specimens whose fossils have been found died. This is a possible indication that adults may have cared for their young and brought them food in a nest until they were able to become independent. Its short existence as a species, of only one million years, may have been due to a poorly developed anatomy, since its small sternum prevented it from having a very agile and powerful flight, and its claws were not the most suitable for climbing cliffs. Its fossils, corresponding to about fifty specimens (about thirty of them relatively complete, the rest being isolated bones), have almost all been found in Germany, except one in France, and many of them are deposited in the State Museum of Natural History in Stuttgart.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Additional text: tubiologia.forosactivos.net/t16744-dorygnathus-banthensis
Dorygnathus banthensis
Artwork: Dmitry Bogdanov
Permission: GNU Free Documentation License, Version 1.2 or any later version
Source: Via Wikipedia
Nautilus toarcensis
Lower Jurassic
Nautilus toarcensis is a species of nautilus that was described by d'Orbigny in 1850. It belongs to the Nautilidae family and the genus Cenoceras.
Findspot: Cruéjouls, Aveyron, France
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Arieten pflaster or ammonite pavement of the Lower Black Jurassic, Bodelshausen near Hechingen. 'Snail pavement' is what people call these layers with closely packed Arieten or ammonites.
The Black Jurassic or Black Jura (German: Schwarzer Jura) in earth history refers to the lowest of the three lithostratigraphic units of the South German Jurassic, the latter being understood not as a geographical, but a geological term in the sense of a lithostratigraphic super group.
The ammonites, which were up to the size of a wagon wheel - not snails, but cephalopods - were washed together before being embedded and deposited mixed with nautilids, mussels and driftwood.
Arietites is a genus of massive, giant evolute, psiloceratacean (Any ammonoid cephalopod of the superfamily Psilocerataceae) ammonites in the family Arietitidae in which whorls are subquadrate and transversely ribbed and with low keels in triplicate, separated by a pair of longitudinal grooves, running along the venter.
( The venter is the lower or ventral side of the ammonite's shell, which is the part that faces toward the organism's belly (as opposed to the dorsal side, which would be on top - Don ). In most ammonites, the venter is the side where the shell is more rounded and smooth. Fossils are known world wide from the lower Sinemurian stage of the Lower Jurassic.
Photo: Don Hitchcock 2015
Source: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Archaeodontosaurus descouensi, mandible.
Holotype of Archaeodontosaurus descouensi, Right mandible.
Archaeodontosaurus ('ancient-toothed lizard') is a genus of sauropod dinosaur from the Middle Jurassic. Its fossils were found in the Isalo III Formation of Madagascar. The type species, Archaeodontosaurus descouensi, was described in September 2005. The specific name honours the collector, Didier Descouens. It is a probable sauropod, with prosauropod-like teeth. It may be a basal member of Gravisauria.
Upper Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Lower Photo: Didier Descouens 2015
Source: Muséum de Toulouse
Permission: Creative Commons Attribution-Share Alike 4.0 International licence.
Araucaria mirabilis
164.7 - 161.2 Mya.
Araucaria mirabilis is an extinct species of coniferous tree from Patagonia, Argentina. It belongs to the genus Araucaria.
Araucaria mirabilis are known from large amounts of very well preserved silicified wood and cones from the Cerro Cuadrado Petrified Forest, including tree trunks that reached 100 m in height in life. The site was buried by a volcanic eruption during the Middle Jurassic, approximately 160 million years ago.
Araucaria forests were distributed globally and formed a major part of the woody flora of the Mesozoic era.
Middle Jurassic
Findspot: Argentina ( probably Cerro Cuadrado Petrified Forest - Don )
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Nautilus belauensis
Having survived relatively unchanged for hundreds of millions of years, nautiluses represent the only living members of the subclass Nautiloidea, and are often considered 'living fossils'.
Fossil records indicate that nautiloids have experienced minimal morphological changes over the past 500 million years. Many were initially straight-shelled, as in the extinct genus Lituites. They developed in the Late Cambrian period and became a significant group of sea predators during the Ordovician period. Certain species reached over 2.5 m in size. The other cephalopod subclass, Coleoidea, diverged from the nautiloids long ago and the nautilus has remained relatively unchanged since.
Age: This specimen is from the present day.
Findspot: Present day, Indo-Pacific Ocean
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Pterodactylus Kochi, viewed at one time as an immature form of Pterodactylus antiquus, but the matter is disputed.
Age: 155.7 - 150.8 Mya, Upper Jurassic
Provenance: Eichstätt, Germany
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Pterodactylus kochi
Probably the original, it is often referred to in the literature as the 'Vienna specimen'.
Dated at around 150 million years old
Pterodactylus kochi was a carnivore, probably preying upon fish and other small animals. Like all pterosaurs, the wing was formed by a skin and muscle membrane, stretching from its elongated fourth finger to its hind limbs. The membrane would have been strong and flexible, but as thick as a postcard.
Though historically considered distinct from Pterodactylus antiquus, most modern analyses of kochi anatomy strongly suggest it represents a juvenile Pterodactylus antiquus. Pterosaur expert Christopher Bennett noted that some allegedly diagnostic kochi anatomy actually reflected measurement errors of the kochi holotype, and that once corrected the two species cannot be adequately distinguished from one another.
Fossils are often excellently preserved in finely layered limestones that can be split into thin plates. The reason is that when the limestones were deposited, the conditions were hostile to life, for example due to a lack of oxygen.
No scavengers, no worms burrowing into the deposit disturbed the embedding of the sunken animal corpses. This meant that they were perfectly preserved. The slab limestones of Solnhofen and Nusplingen are deposits of this type.
Age: Upper Jurassic
Photo: Don Hitchcock 2015
Source: limestone formations in Solnhofen, Germany.
Proximal source and text: Natural History Museum of Vienna
Additional text: Wikipedia, Google Arts and Culture, Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Pterodactylus kochi
This is the corresponding member of the fossil above, one of a pair of fossils, found when the slab was split in two. Such pairs are very important and useful for detailed analysis.
It is a fully grown specimen, with imprints of wing membranes.
Age: Upper Jurassic
Photo: Don Hitchcock 2015
Source: limestone formations in Solnhofen, Germany.
Proximal source and text: Natural History Museum of Vienna
Fossils from the Solnhofen Limestone
About 150 million years ago, towards the end of what we now call the Jurassic Period, much of Europe was covered by the sea. The shoreline ran close to the course of the present day Altmuhl River, near the towns of Solnhofen and Eichstatt, in southern Germany.
The shallow, quiet lagoons that fringed the shore were separated from the ocean by massive sponge mounds and coral reefs. Little could live in these stagnant, very salty lagoons. Around the shore coniferous shrubs grew. Fluttering between them was Archaeopteryx - no longer a dinosaur, but not quite a true bird - it still had teeth, and it had claws on its wings. The air was filled with the whirr and buzz of dragonflies and other insects. Ripples appeared on the lagoon as the wind stirred it. The sky darkened. And in the blink of an eye a storm roared in from the sea. Waves crashed over the reefs and water poured into the lagoons. With it came unsuspecting creatures from the sea -fishes, prawns, lobsters, brittlestars, jellyfish and cuttlefish. Pterosaurs, the flying reptiles, got caught up in the storm and joined them in the turbulent lagoon. None of the animals lived long in the very salty water of lagoon, and as the storm abated dead bodies drifted down into the very fine mud. Nothing could live down there. There was no oxygen and nothing disturbed the corpses as they slowly become entombed in the mud, settling after the storm died away.
150 million years later quarries were dug into limestone that formed from these lime-rich muds. People have quarried and split the fine rock since Roman times, using it as building stone, or, because it is so fine, as lithographic stone, for printing. And every so often, when the quarrymen's chisel splits the rock, it open like the pages of a book on which is written the story of the fossilised remains of the animals that had been caught in the storms. The fossils displayed here form a small part of a large collection provided to the W.A. Museum by Mr Mark Creasy.
Text above from a poster at the Western Australian Museum, 2011.
Further Reading: Frickhinger (1994a, English translation), (1994b, original German), Barthel et al. (1990)
The shrimp or prawn Aeger tipularis.
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Shrimp or prawn, Antrimpos sp.
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source: Western Australian Museum
The cuttlefish Plesioteuthis prisca
Impressions of the soft tissues of some of the arms are preserved.
Squids are cephalopods that have both arms and tentacles. The arms are shorter limbs covered with suction cups. The two tentacles are longer with suction cups only at the ends.
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Additional text: www.scienceandthesea.org
The cuttlefish Plesioteuthis prisca
In some specimens the ink sac is still preserved and the ink, when dissolved in water, can still be used for drawing.
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Coelacanth, Holophagus penicillatus.
The species Holophagus penicillata/penicillatus is now assigned to the genus Undina.
The black, fern-like growths around the fish are called dendrites, and are formed of manganese dioxide. Many Solnhofen fossils show dendrite growth. Bacterial decay might have played a role in their formation.
Coelacanths have existed for over 400 million years. It was once believed to be the link between fish and land animals, because of its two pairs of lobed fins. Evolutionists believed that these lobed fins evolved into legs, allowing the transition to amphibians and then to land dwelling reptiles. Studies to date show that the Coelacanth has changed very little over this vast number of years.
It was thought to have been extinct for about 70 million years, until a live specimen was caught, in 1938, off the coast of Africa, in the Indian Ocean, and has since also been found in Indonesia. It is possible that all of the Coelacanths that lived in the shallow waters died when the meteor hit at the end of the Cretaceous. Those species that lived at great depths survived the impact and are still alive today.
Age: Upper Jurassic
Findspot: Eichstätt, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Fish, Leptolepis knorri.
The genus is one of the earliest recognised teleost genera.
Leptolepis knorri was an extinct species of ray-finned fish.
It was a relatively small fish, estimated to have been about 20 cm - 30 cm long. It had an elongated, streamlined body typical of many fish from this period, with a forked tail and a smooth, tapering shape designed for efficient swimming. The fish had prominent dorsal and anal fins. The pectoral and pelvic fins were well developed and positioned to help with stabilisation and manoeuvering in the water. It was probably a carnivorous predator, feeding on smaller fish and possibly invertebrates.
Age: Upper Jurassic
Findspot: Eichstätt, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Additional text: Various sources
The brittlestar Geocoma planata
Brittle stars are echinoderms closely related to starfish, but they have long, slender arms and a more flexible structure. Geocoma planata lived during the Jurassic period, specifically the Upper Jurassic, and its fossils are often found in marine deposits.
Geocoma planata is characterised by a small, flat, and disk-shaped central body (the discoidal disk) and long, slender arms that radiate from the center. The arms are typically delicate and can be several times the length of the central disk. The species is thought to have had a relatively small size, with the arms extending outwards in a fan-like arrangement.
The arms of Geocoma planata are slender, flexible, and composed of a series of small joints. They are equipped with spines or scales that help in movement and may have provided protection. The arms were likely used for locomotion and feeding. Brittle stars like Geocoma planata are known for their ability to move quickly by flexing their arms, which is why they are often seen as highly mobile creatures.
The surface of the disk and arms was likely covered in tiny, hard, calcareous structures, such as ossicles. These ossicles give the brittle star its rigidity and help with protection against predators. The outer surface could have a smooth or slightly textured appearance, with fine details visible in some fossil specimens.
Like modern brittle stars, Geocoma planata would have lived on the seafloor, likely in shallow marine environments. These creatures are typically found in sedimentary rocks, often from regions that were once marine environments during the Jurassic period.
Brittle stars are generally detritivores or filter feeders, using their arms to capture food particles from the water. Some species are known to feed on plankton or small organic matter that settles on the ocean floor.
Age: Upper Jurassic
Findspot: Weltenburg/Kelheim, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Additional text: Various sources
Three specimens of Geocoma planata, and one of Ophiopetra kelheimensis
Note that Ophiopetra kelheimensis is now classified as Geocoma schoentalensis
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Tharsus dubius
This fish was relatively small (circa 10 to 20 cm) and part of the order Leptolepididae, which were early ray-finned fishes, and which moved in shoals to reduce depradation. These fish had elongated bodies with slender forms, and they were active swimmers. Fossils of Tharsus dubius often show fine details, such as the arrangement of scales, fin structures, and the outline of the body, which have provided important insights into fish evolution during the Jurassic period.
Age: Upper Jurassic
Findspot: Eichstätt, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Additional text: Various sources
Tharsus dubius
This fish became tied in a knot as it dehydrated in the very salty lagoon water.
Age: Upper Jurassic
Findspot: Eichstätt, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Additional text: Various sources
A 'seaweed', Phyllothallus
Phyllothallus are described as 'seaweed - like brown algae' by www.solnhofen-fossilienatlas.de and by hoopermuseum.earthsci.carleton.ca
This plant could only have been transported very quickly to the lagoon sediments in which it was found, since it would normally have been destroyed in only a few hours after death, and would not have been transported very far, or disturbed after transportation.
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Additional text: Various sources
A conifer, Brachyphyllum
It was found in the Mörnsheim Formation near Daiting, Germany, from which specimens of Archaeopteryx were also retrieved.
Age: Upper Jurassic
Findspot: Daiting, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Additional text: Various sources
A Cypress, Palaeocyparis_princeps
This was also found in the Mörnsheim Formation near Daiting, Germany.
Age: Upper Jurassic
Findspot: Daiting, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Additional text: Various sources
Fish, Caturus cyprinoides
Caturids are among the most common and best known predatory ray finned fishes of the Late Jurassic.
Findspot: Eichstätt, Germany
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Additional text: Various sources
A lobster, Eryon arctiformis.
Eryon is an extinct genus of decapod crustaceans from the Upper Jurassic of Germany. Its remains are known from the Solnhofen limestone. It reached a length of around 10 cm, and may have fed on particulate matter on the sea bed.
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Wood wasp, Myrmicium (Pseudosirex) schroeteri
Myrmicium (Pseudosirex) schroeteri is a fossil wasp from the Upper Jurassic period that was found in the Solnhofen Limestone in Germany. It is a type of sawfly, which is part of the Hymenoptera order, which also includes ants, bees, and wasps.
Myrmicium (Pseudosirex) schroeteri was found in the Solnhofen Plattenkalk Formation in Heinheim, Eichstatt, Bavaria, Germany. The fossils are estimated to be around 140 million years old.
Myrmicium is a relatively common fossil insect from the Solnhofen Limestone. It is thought to have been similar to horntails, a group of modern sawflies.
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source: Western Australian Museum
A cockroach, Lithoblatta lithophila
A fossil cockroach from the Upper Jurassic period, that was found in the Solnhofen Limestone in Germany.
Fossils indicate that the species had long wings, like modern examples of cockroaches, which extended to the end or past the end of their abdomens, but with slight differences in wing venation and body structure that are useful for classification.
These cockroaches were relatively small in size, with estimates suggesting a length around 1.5 to 3 cm. Fossil evidence suggests that, like modern cockroaches, Lithoblatta lithophila likely played a role as a detritivore, feeding on decaying organic matter in its environment. It would have contributed to the breakdown of plant and animal material, just as modern cockroaches do today.
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Text: Various sources
A dragonfly, Aeschnidium densum
A fossil dragonfly from the Upper Jurassic period, that was found in the Solnhofen Limestone in Germany.
This places it among some of the earliest dragonfly species, providing key evidence of the evolution of odonates during the Mesozoic Era.
(Odonata is an order of predatory flying insects that includes the dragonflies and damselflies)
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Text: Adapted from Wikipedia
A water scorpion insect, Mesonepa primordialis from the Upper Jurassic period, that was found in the Solnhofen Limestone in Germany.
Mesonepa is from the Nepoidea, a superfamily of hemipteran insects (true bugs) in the subdivision Hydrocorisae. It had swimming legs.
( The common name of 'water scorpion' for this insect is not to be confused with the common name of 'sea scorpion' for the quite different genus Eurypterus from the Silurian period - Don )
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Text: Adapted from Wikipedia
Tarsophlebia major from the Upper Jurassic period, that was found in the Solnhofen Limestone in Germany.
The Tarsophlebiidae is an extinct family of medium-sized fossil odonates from the Upper Jurassic and Lower Cretaceous period of Eurasia. They are either the most basal member of the damsel-dragonfly grade ('anisozygopteres') within the stem group of Anisoptera, or the sister group of all recent odonates. They are characterised by the basally open discoidal cell in both pairs of wings, very long legs, paddle-shaped male cerci, and a hypertrophied ovipositor in females.
(Odonata is an order of predatory flying insects that includes the dragonflies and damselflies)
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Text: Adapted from Wikipedia
Stenophlebia latreillei from the Upper Jurassic period, that was found in the Solnhofen Limestone in Germany.
There are two other members of the genus: Stenophlebia aequalis is somewhat larger, while Stenophlebia casta has a more delicate appearance.
The wings stretched towards the rear are a diagnostic features of this taxon. Notice the fine venation preserved in the wings.
Age: Upper Jurassic
Findspot: Solnhofen, Germany
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Text: Adapted from www.fossilmuseum.net
Ammonite
Longitudinal section to show the chambered shell.
Age: Upper Jurassic
Findspot: Petersbuch, near Eichstätt, Germany
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Mecochirus longimanu is a fossil lobster from the Solnhofen Limestone in Germany, from the Upper Jurassic period.
The species name means 'long arm'. The lobster has an elongated first pair of walking legs that are much longer than the body.
Age: Upper Jurassic
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Text: Various sources
Eryma modestiformis is a fossil lobster from the Solnhofen Limestone, Eichstatt, Germany, from the Upper Jurassic period.
Circa 6 cm long.
Age: Upper Jurassic
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Text: Various sources
Pterodactylus kochi
Upper Jurassic, Solnhofen layers (Lower Tithonian),
Altmühl-Alb, Bavaria. Skeleton in the found position with depiction of soft tissue and flight membrane impressions. Vienna specimen,
NHMW, No. 1975/1756.
Drawing: Wellnhofer (1986), page 152
Source: limestone formations in Solnhofen, Germany.
Sordes pilosus was a small pterosaur from the Upper Jurassic (Oxfordian/Kimmeridgian) Karabastau Svita of Kazakhstan.
A small non-pterodactyloid pterosaur, Sordes pilosus has a rather unfortunate name, given to it in 1971 by Sharov on the basis of a remarkably complete holotype specimen.
The genus name roughly translates as filth or scum while pilosus means hairy, and in general it gives out an air of disgust and loathing, almost like hair caught in a shower drain. However, it is this so-called hair that makes the discovery so interesting.
The animal is from the Kimmeridgian Stage of the Upper Jurassic, circa 155 Mya.
It shared its home with a small anurognathid named Batracognathus, and a few other small vertebrates and insects, which probably made up much of their diets.
Sordes is the first pterosaur to preserve direct evidence of so-called ‘pterofuzz’ or to be more specific, pycnofibres. Pycnofibres were certainly unrelated to the fur coats of syanpsids like mammals. These are filaments that form fur-like integument on the bodies of every pterosaur genus known, even extending down parts of their wing (as in Jeholopterus and Sordes itself), faces (as in Tupandactylus, while not covering the front of the jaws) and tails.
Both pterosaurs and all dinosaurs are part of the group Avemetatarsalia. It is thought that filaments were basal to the group, meaning that they were present in their most ancient common ancestor.
However, from skin impressions of non-avian dinosaurs, we know that some families experienced a secondary loss of such filaments over much of their bodies, including many large herbivores from numerous families and carnivores like Carnotaurus and Ceratosaurus. And of course maniraptorans, which includes birds. Basal coelurosaurs like tyrannosaurs and compsognathids definitely had at least primitive fur-like feathers.
It remains to be seen if even the ornithopod dinosaurs Kulindadromeus and Tianyulong were properly ‘feathered’ or if they just had a fluffy coat by means of convergence with the feathered theropods.
Adding to the confusion, a possible ancestral avemetatarsalian named Scleromochlus, shows signs of at least parts of its body being scaly. No remains of fluffy integument have been found with its fossils. Perhaps it did have them and they were not preserved, or perhaps it did not.
But by now it is almost clear that pterosaurs were warm-blooded and so were dinosaurs. Sordes itself was a small animal with a short wingspan of 60 cm.
Its head was large, and its back teeth were quite strong, adapted for crushing prey while its front teeth were for gripping. No bony or keratinous crests have been found, an unusual factor for most non-pterodactyloids and most pterosaurs in general.
Age: Upper Jurassic
Findspot: Kazakhstan
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Text: A very useful, knowledgeable and extremely well written description from www.pteros.com, possibly by the lead writer Pete Buchholz
Rhamphorhynchus intermedius (Koh, 1937) †
Rhamphorhynchus intermedius is one of the species of the Rhamphorhynchus, an extinct genus of pterosaurs that lived during the Upper Jurassic period, around 150 to 148 million years ago. This genus is well known for its long, toothy jaws and relatively small size compared to other, more massive pterosaurs like Pteranodon or Quetzalcoatlus.
The species was discovered in fossils found in the Solnhofen Limestone of Bavaria, Germany, a famous Lagerstätte (exceptionally well-preserved fossil site) that also preserved other famous Jurassic organisms, such as Archaeopteryx.
Rhamphorhynchus intermedius had a wingspan of approximately 1.5 metres, making it a relatively small pterosaur. The genus is characterised by a long, slender body and a long tail that often ends in a diamond-shaped fin, which is a key feature used to identify species within Rhamphorhynchus. Its long, narrow snout was lined with sharp teeth, which likely allowed it to capture fish or other small prey.
The long tail with a fin-like structure is characteristic of the species and was likely used for stability and manoeuverability in flight.
It had a relatively long and narrow wing structure, with a high aspect ratio, which would have been suited for gliding and long-distance flight.
Rhamphorhynchus intermedius would probably have hunted in coastal or freshwater environments, feeding primarily on fish and possibly other small marine or freshwater organisms. The long tail and wing morphology suggest that it was a highly manoeuvrable flyer, possibly hunting near the water's surface or along coastal cliffs. The well developed teeth and jaw structure suggest it may have used a 'skimming' method of hunting, where it flew low over the water and snapped up fish.
Given the fossil evidence from the Solnhofen Limestone, it is believed that Rhamphorhynchus lived in an environment similar to that of modern seabirds, where open water and shallow coastlines provided both the resources for food and the necessary conditions for flight.
Rhamphorhynchus fossils have been predominantly found in the Solnhofen Limestone, which is part of the Late Jurassic period. This suggests that Rhamphorhynchus intermedius was part of a relatively rich and diverse ecosystem in what is now Germany. The Solnhofen Lagerstätte is known for its high preservation quality, including the preservation of soft tissues, and many species coexisted here, from fish and other marine reptiles to early birds and other pterosaurs.
Age: Upper Jurassic
Photo: Don Hitchcock 2015
Source: Limestone formations in Solnhofen, Germany.
Proximal source: Natural History Museum of Vienna
Text: Various sources
Cresmoda obscura, Water strider.
155.7 - 150.8 Mya (Jurassic)
Age: Upper Jurassic
Provenance: Solnhofen, Germany
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Archaeopteryx lithographica, Syn. Archaeopteryx siemensii (the assessment as a synonym is now disputed) specimen displayed at the Natural History Museum, London. (This image shows the original fossil - not a cast.)
Circa 150 Mya, the Upper Jurassic.
This is the type specimen of the species, the one to which all others are compared. The NHM ranks it as the most valuable specimen in the Museum's collection.
Archaeopteryx was not like modern birds. It had feathers like a bird, but teeth, claws and a bony tail like a dinosaur.
The first skeleton of Archaeopteryx, known as the London Specimen (BMNH 37001), was unearthed in 1861 near Langenaltheim, Germany and perhaps given to a local physician Karl Häberlein in return for medical services. He then sold it for £700 to the Natural History Museum in London, where it remains.
Missing most of its head and neck, it was described in 1863 by Richard Owen as Archaeopteryx macrura, allowing for the possibility it did not belong to the same species as the first feather found.
In the subsequent 4th edition of his On the Origin of Species, Charles Darwin described how some authors had maintained 'that the whole class of birds came suddenly into existence during the eocene period; but now we know, on the authority of Professor Owen, that a bird certainly lived during the deposition of the upper greensand; and still more recently, that strange bird, the Archaeopteryx, with a long lizard-like tail, bearing a pair of feathers on each joint, and with its wings furnished with two free claws, has been discovered in the oolitic slates of Solnhofen. Hardly any recent discovery shows more forcibly than this how little we as yet know of the former inhabitants of the world.'
Age: Upper Jurassic
Photo: Don Hitchcock 2018
Proximal source: The Natural History Museum, London
Text: The NHM and various other sources including Wikipedia
Archaeopteryx lithographica
Circa 150 Mya, the Upper Jurassic.
Fossils of this type often have two matching halves, where the original slab has been split apart, and this is the case here.
This is the 'other half' of the fossil above. The outlines do not completely match, since exploratory work was conducted before it was realised that there was a fossil in the particular bed being investigated.
At this point, the slab was split into two, often a difficult and stressful operation requiring great expertise.
These matching fossils of the same object can be very important for understanding and further research.
Age: Upper Jurassic
Photo: Don Hitchcock 2018
Proximal source: The Natural History Museum, London
Text: The NHM and various other sources including Wikipedia
Reconstruction of Archaeopteryx on display at the NHM.
We are still learning about bird evolution from this fossil. The shape and arrangement of the wing feathers show similar adaptations for flight to modern birds.
Rephotography: Don Hitchcock 2018
Artist: Not listed
Proximal source and text: The Natural History Museum, London
Life size models of a male and female Archaeopteryx. The colours and pattern of the coats are hypothetical.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Natural History Museum scientist Angela Milner led an international team that found further evidence that Archaeopteryx could fly by studying casts of its brain.
The diagram above shows the results of this ground breaking work.
Rephotography: Don Hitchcock 2018
Artist: Not listed
Proximal source and text: The Natural History Museum, London
Archaeopteryx lithographica Syn. Archaeopteryx siemensii (the assessment as a synonym is now disputed) specimen displayed at the Museum für Naturkunde in Berlin. (This image shows the original fossil - not a cast.)
Age: Circa 150 Mya, the Upper Jurassic.
Findspot: Solnhofen Limestone, near Eichstätt in Germany
Photo: H. Raab (User: Vesta)
Permission: Creative Commons Attribution-Share Alike 3.0 Unported licence
Source: Museum für Naturkunde, Berlin, via Wikipedia
Aeschnogomphus intermedius, a dragonfly.
Upper White Jura, Upper Jurassic.
Dragonflies develop in freshwater, but later often cover long distances in flight.
This dragonfly, which had an accident on the high seas and sank to the sea floor, was soon covered by a layer of bacteria and a thin film of lime, a prerequisite for detailed preservation.
Age: Upper Jurassic
Findspot: Eichstalt, Bavaria
Photo: Don Hitchcock 2015
Source and text: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Marine crocodile Dakosaurus maximus lower jaw
Upper White Jura Painten, Franconian Alb
This lower jaw comes from the Franconian Jura. Individual teeth prove that Dakosaurus also lived where the Swabian Alb now stands.
The ancestors of crocodiles separated from the other dominant lizards (archosaurs) over 250 million years ago. The real crocodiles, however, only emerged much later, towards the end of the Triassic period.
Age: Upper Jurassic, 161 - 150 Mya
Photo: Don Hitchcock 2015
Source: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Marine crocodile Dakosaurus maximus skull.
Age: Upper Jurassic
Photo: Don Hitchcock 2015
Source: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Cricosaurus suevicus, SMNS 9808.
From Nusplingen in Baden-Württemberg.
Cricosaurus is an extinct genus of marine crocodyliforms of the Upper Jurassic. belonging to the family Metriorhynchidae.
It was a relatively small reptile, with the body length of specimens ranging from 2 m to 3.2 m.
Its body was streamlined for greater hydrodynamic efficiency, which along with its finned tail made it a more efficient swimmer than modern crocodilian species.
The genus Cricosaurus comprises rather small and slender metriorhynchids, which likely preyed on fast-moving animals like squids and fish as evident by the small teeth and preserved belemnite rostra in the abdominal region of a specimen from Nusplingen.
Age: Upper Jurassic
Photo: Don Hitchcock 2015
Source: Naturkunde Museum Stuttgart, State Museum of Natural History, Stuttgart
Text: Various sources including Wikipedia
Earth during the Cretaceous, circa 105 million years ago
A mollweide (equal-area) projection map of Earth 105 million years ago, overlain by a black outline of present-day countries in their respective locations.
Image: Scotese, Christopher R.; Vérard, Christian; Burgener, Landon; Elling, Reece P.; Kocsis, Ádám T
Permission: Creative Commons Attribution 4.0 International, via Wikipedia
Text on map added by Don Hitchcock
During the Cretaceous, dinosaurs great and small moved through lush rainforests of ferns, cycads and conifers in the Cretaceous, 135 Mya - 65 Mya. Flowering plants called angiosperms appeared at this time. Many groups of insects were also starting to diversify into species we would recognise today - ants, bees, butterflies, aphids, grasshoppers and termites.
A huge number of plants and animals, including dinosaurs, died out suddenly at the end of the Cretaceous, 66 million years ago, as a direct result of the crash of a meteorite in Mexico.
Text above adapted from a poster in the Western Australian Museum.
Axelrodichthys araripensis.
Axelrodichthys is an extinct genus of mawsoniid coelacanth from the Cretaceous of Africa, North and South America, and Europe.
Mawsoniidae is an extinct family of prehistoric coelacanth fishes which lived during the Triassic to Cretaceous periods.
This specimen has been superbly prepared for display by the curators of Le Muséum d'Histoire Naturelle de Toulouse.
Several species are known, the remains of which were discovered in the Lower Cretaceous (Aptian-Albian) of Brazil, North Africa, and possibly Mexico, as well as in the Upper Cretaceous of Morocco (Cenomanian), Madagascar (Coniacian –Santonian) and France (Lower Campanian to Lower Maastrichtian).
The Axelrodichthys of the Lower Cretaceous frequented both brackish and coastal marine waters (lagoon-coastal environment) while the most recent species lived exclusively in fresh waters (lakes and rivers). The French specimens are the last known fresh water coelacanths. Most of the species of this genus reached 1 to 2 metres in length. Axelrodichthys was named in 1986 by John G. Maisey in honor of the American ichthyologist Herbert R. Axelrod.
Findspot: Brazil
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Adapted from Wikipedia
Ancyloceras
Ancyloceras is an extinct genus of heteromorph ammonites found throughout the world during the Lower Cretaceous, from the Lower Barremian epoch until the genus extinction during the Lower Aptian.
Ancyloceras ammonites have a shell reaching a length of about 10 centimetres (3.9 in) and a width of about 7 centimetres (2.8 in). They are known as heteromorph shaped, with a partly uncoiled shell and the aperture directed toward the coiled part.
Most ammonites are homomorph, as they maintain the same shape throughout the growth, while the ammonites in this genus have uncoiled shells (heteromorph or different-shaped ammonites), that would have precluded fast swimming.
Findspot: Agadir, Morocco
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Additional text: Wikipedia
Ammonites from the Lower Cretaceous, Macrosdaphites recticostatus and Heteroceras emericianus
Left:
Macroscaphitidae (meaning long boat) is an extinct family of ptychoceratoid cephalopods from the subclass Ammonoidea that lived from the Lower Barremian to the Lower Cenomanian stages of the Cretaceous.
Fossils of Macroscaphitidae were found all around the world although the abundance of found fossils is rather limited. It is known for some species of which complete specimens were found that these animals developed a heteromorphic shell, i.e. the coiling of the shell was not regular, such that the first whirls formed a planispirally coiled evolute section as seen in homomorphic ammonites, but had an additional straight middle part and a presumably upwards facing aperture.
( This additional straight part is missing in the images of many published specimens, as in this case - Don )
Due to their odd morphology the taxonomic classification of Macroscaphitidae changed often over time since their discovery and may not be finally settled even now.
Right:
( Note that for Heteroceras emericianus the original name was Turrilites emericianus A. d'Orbigny, 1842, and several spellings exist in the literature including Heteroceras emerici and Heteroceras emericianum - Don )
Cretaceous heteromorph ammonites of the suborder Ancyloceratina had a striking ontogenetic change in their shell shape. Juveniles had virtually all possible types of coiling of their shells, ranging from regular planispiral and orthoconic to torticonic, hamitoconic and gyroconic. The adults uncoiled the last whorl of their shell forming a U-shaped recurved body chamber with the aperture facing upward.
Examination of ribbing pattern and its resolution in various parts of the living chamber in 11 species revealed that the ribs were less developed and had some traces of wear on the inner surface of the hooked chamber, being well developed both on the lateral and outer lower parts. This could indicate that the adult animals were semi-loosely hooked (Ancyloceras, Macroscaphites) or permanently clipped (Scaphites, Hoploscaphites) onto either horizontal or upwardly angled stipes of non-calcified algal macrophytes or branched animals.
Comparison of the adult mode of life with those of modern cephalopods suggested that ammonites of the suborder Ancyloceratina had developed a stationary brooding phase that could have several ecological advantages over free-swimming monomorph ammonites.
Findspot: Alpes-de-Haute-Provence, France
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Adapted from Wikipedia, and from Arkhipkin (2014)
Australiceras jacki, ammonite, Lower Cretaceous.
Findspot: Queensland, Australia
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Archaefructus sinensis
Archaefructus is an extinct genus of herbaceous aquatic seed plants with three known species. Fossil material assigned to this genus originates from the Yixian Formation in northeastern China, originally dated as late Jurassic but now understood to be approximately 125 million years old, or Lower Cretaceous in age. Even with its revised age, Archaefructus has been proposed to be one of the earliest known genera of flowering plants.
Findspot: Chaoyang, Liaoning, China
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Wikipedia
Diptera
Fly, 125 Mya - 112 Mya, Lower Cretaceous, from Ceará, Araripe, Brazil.
A rich insect fauna is found in the Cretaceous (Aptian) Nova Olinda Member of the Crato Formation in the Araripe Basin, northeastern Brazil, a facies of pale yellow and dark grey limestones.
The Araripe Basin is located in the Northeast region of Brazil, between the states of Ceará, Pernambuco, Piauí and Paraíba. This basin has an area of about 9000 km2, of which > 50% are over the Ceará territory.
Findspot: Ceará, Araripe, Brazil
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Bezerra & Mendes (2024)
Snakefly
Raphidioptera, 140 Mya - 137 Mya, Lower Cretaceous
Snakeflies are a group of predatory insects comprising the order Raphidioptera with two extant families: Raphidiidae and Inocelliidae, consisting of roughly 260 species. In the past, the group had a much wider distribution than it does now; snakeflies are found in temperate regions worldwide but are absent from the tropics and the Southern Hemisphere. Recognisable representatives of the group first appeared during the Early Jurassic. They are a relict group, having reached their apex of diversity during the Cretaceous before undergoing substantial decline.
An adult snakefly resembles a lacewing in appearance but has a notably elongated thorax which, together with the mobile head, gives the group their common name. The body is long and slender and the two pairs of long, membranous wings are prominently veined. Females have a large and sturdy ovipositor which is used to deposit eggs in some concealed location. They are holometabolous (i.e. they undergo a complete metamorphosis) insects with a four-stage life cycle consisting of eggs, larvae, pupae and adults. In most species, the larvae develop under the bark of trees. They may take several years before they undergo metamorphosis, requiring a period of chilling before pupation takes place. Both adults and larvae are predators of soft-bodied arthropods.
Findspot: Chaoyang, Liaoning, China
Photo (upper, of a modern snakefly, Dichrostigma flavipes): Beentree, GNU Free Documentation License, Version 1.2 or any later version.
Photo (lower, of the fossil): Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Wikipedia
Gnetale, Ephedraceae, 125 Mya - 112 Mya, Lower Cretaceous.
Gnetales are small relict order of chiefly tropical or xerophytic gymnosperms that includes the genera Gnetum, Welwitschia and Ephredra.
Ephedraceae is a family of gymnosperms belonging to Gnetophyta, it contains only a single extant genus, Ephedra, as well as a number of extinct genera from the Lower Cretaceous.
Findspot: Ceará, Araripe, Brazil
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Gnat, Diptera, 140 Mya - 136 Mya, Lower Cretaceous.
Findspot: Chaoyang, Liaoning, China
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Dragonfly, Sinocymatopblebia magnifica, 125 Mya - 112 Mya, Lower Cretaceous.
( I have been unable to find any description of this species on the internet, as at February 2025, yet someone must have given it its name, and described it - Don )
Findspot: Ceará, Araripe, Brazil
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Sturgeon - Yanosteus longidorsalis, Lower Cretaceous
A member of the extinct family Peipiaosteidae.
Findspot: Longfengshan, Fengning, China
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text:
Hyphalosaurus lingyuanensis, Lower Cretaceous
Hyphalosaurus (meaning 'submerged lizard') is a genus of freshwater aquatic reptiles, belonging to the extinct order Choristodera. They lived during the Lower Cretaceous period (late Barremian to early Aptian age), about 123-120 million years ago.
The genus contains two species, Hyphalosaurus lingyuanensis from the Yixian Formation and Hyphalosaurus baitaigouensis from both the Yixian and Jiufotang Formation of Liaoning Province, China. They are among the best-known animals from the Jehol Biota, with thousands of fossil specimens representing all growth stages in scientific and private collections.
Findspot: Chaoyang, Liaoning, China
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Wikipedia
Skull of the pterosaur Tropeognathus mesembrinus, Lower Cretaceous
Tropeognathus (meaning 'keel jaw') is a genus of large pterosaurs from the late Lower Cretaceous of South America. This genus is considered to be a member of the family Anhangueridae, however, several studies have also recovered it within another family called Ornithocheiridae. Both of these families are diverse groups of pterosaurs known for their keel-tipped snouts and large size.
Tropeognathus is regarded as the largest pterosaur found in the Southern Hemisphere, only rivalled by the huge azhdarchids. The type and only species is Tropeognathus mesembrinus. Fossil remains of Tropeognathus have been recovered from the Romualdo Formation, which is a Lagerstätte located in the Santana Group of the Araripe Basin in northeastern Brazil.
Its unusual 'keel jaw' was well suited to its task of capturing fish from the prehistoric oceans around what is now South America. It could have used it to pluck the fish right out of the water and use its enormous teeth to hold on to them. Then it could have simply swallowed them whole.
Findspot: South America
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Text: Adapted from Wikipedia and newdinosaurs.com
Caudipteryx zoui was an antecedent of modern birds which occurred in Asia and Australia.
This specimen is a cast of the original fossil of Caudipteryx zoui which was about the size of a modern turkey, from the early Cretaceous, 120 Mya, Liaoning Province, China.
Birds form a branch within the dinosaur evolutionary tree. They developed during the Jurassic period more than 150 million years ago. Their ancestors were Coeluroasaurs, a group of dinosaurs including Tyrannosaurus, Oviraptor, and Deinonychus. Birds are the last dinosaurs.
Feathers originated within the dinosaurs several times independently from scales. They might have served primarily for thermoregulation, brood care, or for display, and were adapted later for flight.
Pennaceous feathers, which are essential for active flight, are characterised by a stiff shaft and barbs. They evolved about 150 million years ago.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna, and the Australian Museum.
Deinonychus is a genus of dromaeosaurid theropod dinosaur with one described species, Deinonychus antirrhopus. This species, which could grow up to 3.4 meters long, lived during the Lower Cretaceous Period, about 115–108 million years ago. Fossils have been recovered from the U.S. states of Montana, Utah, Wyoming, and Oklahoma, in rocks of the Cloverly Formation and Antlers Formation, though teeth that may belong to Deinonychus have been found much farther east in Maryland.
Deinonychus antirrhopus weighed around 74 kg. Its sickle-claws made it one of the most dangerous predators of the Cretaceous period.
Palaeontologist John Ostrom's study of Deinonychus in the late 1960s revolutionised the way scientists thought about dinosaurs, leading to the 'dinosaur renaissance' and igniting the debate on whether dinosaurs were warm-blooded or cold-blooded. Before this, the popular conception of dinosaurs had been one of plodding, reptilian giants. Ostrom noted the small body, sleek, horizontal posture, ratite-like spine, and especially the enlarged raptorial claws on the feet, which suggested an active, agile predator. The ratites are flightless birds with flat, smooth breastbones, similar to a raft such as the modern emu and ostrich.
'Terrible claw' refers to the unusually large, sickle-shaped talon on the second toe of each hind foot. The fossil YPM 5205 preserves a large, strongly curved claw. In life, archosaurs ( a group which includes the most recent common ancestor of living birds and crocodilians, and all of its descendants) have a horny sheath over this bone, which extends the length. Ostrom looked at crocodile and bird claws and reconstructed the claw for YPM 5205 as over 120 millimetres long. The species name antirrhopus means 'counter balance', which refers to Ostrom's idea about the function of the tail.
As in other dromaeosaurids, the tail vertebrae have a series of ossified tendons and super-elongated bone processes. These features seemed to make the tail into a stiff counterbalance, but a fossil of the very closely related Velociraptor mongoliensis (IGM 100/986) has an articulated tail skeleton that is curved laterally in a long S-shape. This suggests that, in life, the tail could bend to the sides with a high degree of flexibility. In both the Cloverly and Antlers formations, Deinonychus remains have been found closely associated with those of the ornithopod Tenontosaurus. Teeth discovered associated with Tenontosaurus specimens imply they were hunted, or at least scavenged upon, by Deinonychus.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Additional text: Wikipedia
Araripescorpius ligabuei
125 - 112 Mya
Scorpion, Lower Cretaceous.
Terrestrial carnivore.
Found: In an Aptian lacustrine - large carbonate in the Crato Formation of Brazil. It is the type species of Araripescorpius.
Findspot: Ceará, Araripe, Brazil
Photo: Don Hitchcock 2015
Text: Various sources
Source: Muséum de Toulouse
Frog, Lower Cretaceous.
Pipidae.
125 - 112 Mya
Present day Pipid frogs are highly aquatic and have numerous morphological modifications befitting their habitat. For example, the feet are completely webbed, the body is flattened, and a lateral line system is present in adults. In addition, pipids possess highly modified ears for receiving sound under water. They lack a tongue or vocal cords, instead having bony rods in the larynx that help produce sound. They range from 4 to 19 cm in body length.
Findspot: Ceará, Araripe, Brazil
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Text: Adapted from Wikipedia
Hypsilophodon, Lower Cretaceous, facsimile.
A member of the Ornithischia clade of mainly herbivorous dinosaurs characterised by a pelvic structure superficially similar to that of birds.
130 - 125 Mya, herbivorous, length up to 2 metres, weight 20 kg.
Hypsilophodon was a small, agile dinosaur that lived in prehistoric England. It lived on the ground and was good at running.
Several Hypsilophodon individuals were discovered together at one fossil site, suggesting they lived and died together. Some experts say this dinosaur probably lived in groups, like deer.
Findspot: England, UK
Photo: Don Hitchcock 2011
Source: Western Australian Museum
Text: Adapted from www.nhm.ac.uk
Wasp, Hymenoptera, 125 Mya - 112 Mya, Middle Cretaceous.
Findspot: Ceará, Araripe, Brazil
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Caudipteryx zoui was a dinosaur that lived about 125 million years ago during the Middle Cretaceous period, and mostly ate plants. It was covered in short downy feathers and had longer feathers on its arms and tail.
It had a short snout and few teeth and but was able to eat some animals as well as plants. It had downy feathers covering most of its body, which helped it to keep warm. Its long wing and tail feathers were probably used for display or brooding.
It was named in 1998 and was the third feathered dinosaur found in Liaoning Province. Caudipteryx means 'tail feather' referring to the tail plume that the dinosaur may have fanned out for display.
It had pennaceous symmetrical feathers at the end of its tail and its short arms.
Painting: James Reece© Australian Museum
Text: Australian Museum
Ginkgo sp.
112 - 99.6 Mya
Middle Cretaceous
Ginkgo is a genus of non-flowering seed plants, assigned to the gymnosperms. The scientific name is also used as the English common name. The order to which the genus belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, and Ginkgo is now the only living genus within the order. The rate of evolution within the genus has been slow, and almost all its species had become extinct by the end of the Pliocene. The sole surviving species, Ginkgo biloba, is found in the wild only in China, but is cultivated around the world. The relationships between ginkgos and other groups of plants are not fully resolved.
Findspot: Lake Baikal, Siberia
Photo: Don Hitchcock 2015
Text: Various sources
Source: Muséum de Toulouse
Calamopleurus cylindricus
A fresh water fish from the Middle Cretaceous.
( The lower image showing the impressive teeth of Calamopleurus cylindricus gives a good idea of why this species was so large - prey did not stand a chance! - Don )
Calamopleurus is a prehistoric genus of marine halecomorph ray-finned fish from South America and northern Africa. It was a relative of the modern bowfin, with both belonging to the family Amiidae.
Calamopleurus cylindricus was among the largest known amiids, rivalling the giant Palaeocene bowfin Amia pattersoni
in size. However, both were slightly smaller than Melvius and Amia basiloides, the two largest known amiids. It is one of the earliest known amiids to evolve a large body size.
Findspot: Céarà, Brazil
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Additional text: Wikipedia
Psittacosaurus mongoliensis.
'Parrot Lizard', Upper Cretaceous, 100 Mya, Mongolia.
This small ceratopsian developed a few hollow, bristle-like feathers along the upper side of the tail.
Psittacosaurus were obligate bipeds at adulthood, with a high skull and a robust beak. One individual was found preserved with long quills on the tail, similar to those of Tianyulong, yet scales of varying sizes and shapes across the rest of the animal. Psittacosaurus probably had complex behaviours, based on the proportions and relative size of the brain. It may have been active for short periods of time during the day and night, and had good smell and well developed vision.
Psittacosaurus is a genus of extinct ceratopsian dinosaurs from the Early Cretaceous of what is now Asia, existing between 125 and 100 million years ago. It is notable for being the most species-rich non-avian dinosaur genus. Up to 12 species are known, from across China, Mongolia, Russia, and Thailand. Psittacosaurus were obligate bipeds at adulthood, with a high skull and a robust beak. One individual was found preserved with long filaments on the tail, similar to those of Tianyulong. Psittacosaurus probably had complex behaviours, based on the proportions and relative size of the brain. It may have been active for short periods of time during the day and night, and had well-developed senses of smell and vision.
Psittacosaurus is one of the most completely known dinosaur genera. Fossils of hundreds of individuals have been collected so far, including many complete skeletons. Most age classes are represented, from hatchling through to adult, which has allowed several detailed studies of Psittacosaurus growth rates and reproductive biology. The abundance of this dinosaur in the fossil record has led to the labelling of Lower Cretaceous sediments of east Asia as the Psittacosaurus biochron.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Additional text: Wikiwand, dino.fandom.com/wiki/Psittacosaurus
Dolichorhynchops osborni
Cretaceous, 88 Mya, Upper Cretaceous, Kansas, USA.
Plesiosaurs and mosasaurs were the most dangerous carnivores in the seas of the Mesozoic era. Strong paddle-like limbs made them excellent swimmers. The fins of the plesiosaurs are reminiscent of airplane wings and suggest that the animals glided through the water like penguins. The short-necked plesiosaurs, such as Dolichorhynchops were high-speed hunters and the fastest swimmers of their time. They were around 3 metres long.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Pteranodon ingens
Upper Cretaceous, 85 Mya, USA, facsimile.
The wingspan of this individual was 4.5 metres. A bony comb at the back of the head was up to 60 cm long and improved flight stability. The head decoration differed in males and females, and, therefore, probably played an important role in courtship.
Pteranodon hunted above the sea and nested on cliffs. Its long bill was perfect for snatching fish from the water while in flight. The prey was then stored in the wide throat pouch. Some pterosaurians might even have undertaken seasonal migrations between continents, like today's migrating birds.
Findspot: USA.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Speetoniceras versicolor
This is a superbly sagittally sliced and polished ammonite from the Cretaceous.
Soon after death, this ammonite was covered with mud. Sulphur was released during decay and fused with free iron, forming a crust of pyrite. The walls of the empty chambers were coated with calcite and pyrite.
Millions of years later, carbonate saturated water soaked through pores to reach the chambers of the ammonite, and allowed yellow and pink calcite crystals to grow.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Parapuzosia seppenradensis
Parapuzosia seppenradensis, 85 Mya, from the Upper Cretaceous, is the largest known species of ammonite. It lived during the Late Cretaceous period, in marine environments in what is now Westphalia, Germany. A specimen, found in Seppenrade near Lüdinghausen, Germany, in 1895, measures 1.8 m (5.9 ft) in diameter, although the living chamber is incomplete. Ammonites became extinct at the same time as the non-bird dinosaurs.
( Note that this specimen has apparently become distorted (by compression left to right in this image) from what was presumably originally a
quasi-circular shape. All other photographs of this particular specimen on the internet show a similar compression - Don )
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Additional text: Wikipedia
Nostoceras, from the Upper Cretaceous, is an extinct genus of ammonites. The etymology of the name Nostoceras comes from 'nostos' meaning return and 'ceros' meaning horn, named as such because it bends back on itself.
Nostoceras is the type genus for the ammonite family Nostoceratidae which is included in the Turrilitoidea.
Findspot: Wyoming, USA
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Additional text: Wikipedia
Diplomystus birdi, marine, deposited in a warm, shallow sea, Upper Cretaceous.
Diplomystus is an extinct genus of freshwater and marine ray-finned fish distantly related to modern-day extant herrings, anchovies, and sardines. It is known from the United States, China, and Lebanon from the Upper Cretaceous to the Middle Eocene.
Findspot: Haqil, Lebanon, Sannine Formation
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Wikipedia, www.fossilera.com
Rhynchodercetis hakelensis, from the Upper Cretaceous of Lebanon.
Rhynchodercetis (meaning 'beaked throat whale') is a genus of prehistoric ray-finned fishes, sometimes with the common name 'Needle Fish'.
Findspot: Haqil, Lebanon, Sannine Formation
Photo: Don Hitchcock 2015
Source and text: Muséum de Toulouse
Additional text: Wikipedia
Nursallia goedeli
Nursallia is an extinct genus of pycnodontid ray-finned fishes, ranging from the Upper Cretaceous period until its extinction during the Eocene.
Known for its incredibly well-preserved fish and crustaceans, the sublithographic limestone of the Cretaceous of Lebanon also preserved incredible detail here as well in this newly-discovered Pynodont taxon known as Nursallia. The family derives its name from the Greek for 'thick tooth'. These fish led a durophagous existence, crushing the shells of shellfish and crustaceans (note the teeth). The genus was erected in 1987 to house several fish that were previously assigned to Paleobalistum, a genus which now consists solely of the fish Paleobalistum orbiculatum.
Findspot: Haqil, Lebanon
Photo: Don Hitchcock 2015
Source: Muséum de Toulouse
Additional text: www.fossilmall.com
Muramotoceras cf. yezoense (top), Mezopuzosia, Hypophylloceras sp. and Anagaudryceras sp.
Muramotoceras was an unusual genus of heteromorphic ammonite. Its remains likely date to the middle Turonian, from 94 Mya - 90 Mya, Upper Cretaceous
Findspot: Hokkaido, Japan
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Carnotaurus sastrei was a meat eating dinosaur, or theropod, from the Upper Cretaceous. It weighed one ton, and was 7.5 m long and 4 m high.
The word Carnotaurus means 'flesh-eating bull', in reference to the fact that this dinosaur ate meat and had two short horns. It ran at about 15 km/h, compared with Tyrannosaurus rex at 17 km/h.
Its likely food sources included large, long-necked plant-eating dinosaurs, or sauropods.
Findspot: Argentina
Photo: Don Hitchcock 2011
Source and text: Western Australian Museum
Protoceratops andrewsi
Upper Cretaceous, 80 Mya, Mongolia.
Protoceratops (first horned face) is a genus of small dinosaurs that lived in Asia during the Late Cretaceous, around 75 to 71 Mya. The genus Protoceratops includes two species: Protoceratops andrewsi and the larger Protoceratops hellenikorhinus. The former was described in 1923 with fossils from the Mongolian Djadokhta Formation, and the latter in 2001 with fossils from the Chinese Bayan Mandahu Formation. Protoceratops was initially believed to be an ancestor of ankylosaurians and larger ceratopsians, such as Triceratops and relatives, until the discoveries of other protoceratopsids. Populations of Protoceratops andrewsi may have evolved into Bagaceratops through anagenesis.
Protoceratops were small ceratopsians, up to 2–2.5 m long and around 62–104 kg in body mass. While adults were largely quadrupedal, juveniles had the capacity to walk around bipedally if necessary. They were characterised by a proportionally large skull, short and stiff neck, and neck frill. The frill was likely used for display or intraspecific combat, as well as protection of the neck and anchoring of jaw muscles.
A horn-like structure was present over the nose, which varied from a single structure in Protoceratops andrewsi to a double, paired structure in Protoceratops hellenikorhinus. The 'horn' and frill were highly variable in shape and size across individuals of the same species, but there is no evidence of sexual dimorphism. They had a prominent parrot-like beak at the tip of the jaws. Protoceratops andrewsi had a pair of cylindrical, blunt teeth near the tip of the upper jaw.
The forelimbs had five fingers of which only the first three bore wide and flat unguals (highly modified distal toe bone which ends in a hoof, claw, or nail). The feet were wide and had four toes with flattened, shovel-like unguals, which would have been useful for digging through the sand. The hindlimbs were longer than the forelimbs. The tail was long and had an enigmatic sail-like structure, which may have been used for display, swimming, or metabolic reasons.
Photo: Don Hitchcock 2015
Text: Wikipedia
Source: Natural History Museum of Vienna
Protoceratops andrewsi
Protoceratops, like many other ceratopsians, were herbivores equipped with prominent jaws and teeth suited for chopping foliage and other plant material. They are thought to have lived in highly sociable groups of mixed ages. They appear to have cared for their young. They laid soft-shelled eggs, a rare occurrence in dinosaurs. During maturation, the skull and neck frill underwent rapid growth. Protoceratops were hunted by Velociraptor, and one particularly famous specimen ('The Fighting Dinosaurs') preserves a pair of them locked in combat. Protoceratops used to be characterised as nocturnal because of the large sclerotic ring around the eye, but they are now thought to have been cathemeral (active at dawn and dusk).
Photo: Don Hitchcock 2015
Text: Wikipedia
Source: Natural History Museum of Vienna
These dinosaur eggs in the Natural History Museum of Vienna appear to have been identified in two different ways:
1. The Natural History Museum of Vienna, which displays them, labels them as eggs of Tarbosaurus (meaning 'alarming lizard'), which is a genus of a large tyrannosaurid dinosaur that lived in Asia during the Late Cretaceous epoch, about 70 million years ago. It contains the single type species Tarbosaurus bataar, which is known from the Nemegt Formation of Mongolia, with more fragmentary remains found further afield in the Subashi Formation of China.
2. Other sources label them as Macroelongatoolithus eggs. Macroelongatoolithus is an oogenus ( that is, a genus used to classify fossilised dinosaur eggs of large theropod dinosaur eggs - Don ) representing the eggs of giant caenagnathid oviraptorosaurs. They are known from Asia and from North America. Historically, several oospecies have been assigned to Macroelongatoolithus, however they are all now considered to be a single oospecies: Macroelongatoolithus carlylensis.
The website dinopedia.fandom.com/wiki/Macroelongatoolithus states that: 'While they are occasionally considered to be the eggs of tyrannosaurs (like Tarbosaurus) on the basis of their huge size, most evidence suggests that they are eggs of gigantic oviraptorids like Gigantoraptor'.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Additional text: Various sources, including Wikipedia
Egg of a titanosaur.
Upper Cretaceous, 70 Mya, Rousset de Provence, France. These eggs are often attributed to Hypselossaurus priscus.
Titanosaurs were a diverse group of sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thriving at the time of the extinction event at the end of the Cretaceous. This group includes some of the largest land animals known to have ever existed, such as Patagotitan from Argentina, estimated at 37 metres long with a weight of 69 tonnes, and the comparably-sized Argentinosaurus and Puertasaurus from the same region.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Skull of Triceratops_horridus, from the Upper Cretaceous, (facsimile, original 70 Mya).
Triceratops is a genus of chasmosaurine ceratopsian dinosaur that lived during the late Maastrichtian age of the Late Cretaceous period in what is now western North America.
Triceratops travelled in herds. The horns and the frill of the herbivore were probably not primarily for defense, but probably served more for turf wars between males, comparable to modern antelopes and bulls.
Findspot: South Dakota, USA.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Additional text: Wikipedia
Skull of Tyrannosaurus rex from the Upper Cretaceous, (facsimile, original 70 Mya).
The huge predator Tyrannosaurus rex was among the last very successful dinosaurs. Like Triceratops, these animals were the victims of a meteor impact.
Findspot: South Dakota, USA.
Photo: Don Hitchcock 2015
Source and text: Natural History Museum of Vienna
Additional text: Wikipedia
The death of the large dinosaurs
Sixty-six million years ago, dinosaurs had the ultimate bad day. With a devastating asteroid impact, a reign that had lasted 180 million years was abruptly ended.
In 1980, Nobel Prize-winning physicist Luis Walter Alvarez and his geologist son Walter published a theory that a historic layer of Iridium-rich clay was caused by a large asteroid colliding with Earth.
The instantaneous devastation in the immediate vicinity and the widespread secondary effects of an asteroid impact were considered to be why the non-bird dinosaurs died out so suddenly.
The crater caused by the asteroid, called the Chicxulub crater, is centred on the Yucatán Peninsula in Mexico.
The asteroid is thought to have been between 10 and 15 kilometres wide, but the velocity of its collision caused the creation of a much larger crater, 150 kilometres in diameter. It is the second-largest crater on the planet.
Other life forms eradicated by the asteroid impact included the Ammonites and large marine reptiles.
Iridium is one of the rarest metals found on Earth. It is usually associated with extraterrestrial impacts, as the element occurs more abundantly in meteorites. The dinosaur-killing crash threw huge amounts of debris into the air and caused massive tidal waves to wash over parts of the American continents. There is also evidence of substantial fires from that point in history. The exact date of the dinosaur extinction is 66.05 million years ago.
The Vredefort impact structure is the largest verified impact structure on Earth. The crater, which has since been eroded away, has been estimated at 170–300 kilometres across when it was formed 2.023 billion (± 4 million) years ago.
Photo: © Don Davis, Via NASA Image and Video Library
Text: Adapted from www.science.org/doi/10.1126/sciadv.abe3647 and Wikipedia
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