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/Dinosaur and Prehistoric Animal News Stories

Fossil finds, new dinosaur discoveries, news and views from the world of palaeontology and other Earth sciences.

19 04, 2018

Carboniferous Shark Brain Case Study

By | April 19th, 2018|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Brain Case of Carcharopsis wortheni Described

Research led by American Museum of Natural History scientists has provided a fresh perspective on a shark that might have been the “Jaws” of the Carboniferous.  The shark, Carcharopsis wortheni was first scientifically described in the mid-19th Century and was previously known only from its characteristic serrated teeth and fragments of jaw.  A fossilised brain case identified as C. wortheni was excavated in 2007 from Upper Mississippian aged rocks in Arkansas (Fayetteville Shale).  The fossil was found by Royal Mapes, a retired Ohio University professor and a research associate at the Museum.  State-of-the-art imaging techniques were used to provide a unique insight into this important apex predator that lived some 320 million years ago.

The Fossil Cranium (Brain Case) of Carcharopsis wortheni

The fossilised brain case of C. wortheni.

The brain case of Carcharopsis wortheni.

Picture Credit: American Museum of Natural History/Allison Bronson

Insight into Shark Evolution

The shark lived at a critical point in the evolutionary history of our planet, part of a marine fauna that survived the end Devonian mass extinction event which decimated vertebrate species.  This ancient Palaeozoic shark,  was originally described in 1843 based on its distinctive serrated teeth, a feature that is common in extant sharks such as the formidable Great White (Carcharodon carcharias), an apex marine predator with a frightening reputation, thanks in the main to the film “Jaws” directed by Steven Spielberg, which was based on Peter Benchley’s book.  However, serrated teeth are rarely found in Palaeozoic sharks.

A CT Scan Showing the Unique Serrations on a Tooth from Carcharopsis (C. wortheni)

Shark fossil tooth C. wortheni.

Carcharopsis fossil tooth.  Scale bar = 1 mm.

Picture Credit: American Museum of Natural History/Allison Bronson

The picture above shows a computer tomography generated image of a Carcharopsis tooth, measuring around five millimetres in length.  The blue lines are canals identified within the tooth.

Commenting on the fossil, lead author of the study Allison Bronson, a PhD student at the American Museum of Natural History stated:

“They [the teeth] look a little like what you’d see in a Great White, but are 320 million years old and with different enamel.  This is really early to see serrated teeth.”

Royal Mapes donated the brain case specimen to the New York-based natural history museum, along with a remarkable 540,000 other fossils.  Mapes co-authored the Carcharopsis study, which has been published in the journal “Papers in Palaeontology”, American Museum of Natural History curator John Maisey also contributed to the paper.

The scientists used high-resolution computed tomography (CT) imaging to examine the cranium, a tooth, and an isolated portion of a tooth base.  Using the scans, they were able to reconstruct the internal canals of the teeth for the first time and found that these are similar to the canals found in today’s sharks.

The arrangement of the shark’s blood vessels—also revealed through CT scans—suggests that Carcharopsis was probably closely related to the group of ancient cartilaginous fish from which today’s sharks and rays evolved.  However, more complete fossils are needed to firmly position it in the tree of life.

Everything Dinosaur acknowledges the help of the American Museum of Natural History in the compilation of this article.

18 04, 2018

A New Early Cretaceous Amphibian from Japan

By | April 18th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Under the Noses of Dinosaurs, a New Species of Early Cretaceous Amphibian is Described

A small, fragmentary fossil found in an outcrop of the Kuwajima Formation, in western Central Japan has been identified as a new species of albanerpetontid amphibian.  This tiny animal, measuring just six centimetres in length inhabited a wide floodplain, that was crossed by meandering rivers in a humid environment some 130 million years ago.  The fossils represent the oldest example of this type of Tetrapod found in Asia, they predate the only other specimens known from Asia (Uzbekistan), by tens of millions of years.

A Life Reconstruction of the Little Albanerpetontid Amphibian (S. isajii)

Shirerpeton life reconstruction.

An illustration of Shirerpeton – an Early Cretaceous amphibian.

Picture Credit: Takumi Yamamoto

The Ancient Albanerpetontidae Family

Superficially resembling modern-day Salamanders, these ancient amphibians are only distantly related to their modern counterparts.  They evolved in the Middle Jurassic and persisted until very recently, finally becoming extinct during the Pleistocene Epoch.  Several genera are known and they are characterised by their unique skulls and the presence of bony scales on their skin.  The tiny specimen consists of a partial skull, vertebrae and elements from a hind limb, a total of forty-three bones.  The only Asian examples of this clade of amphibian have been found in Uzbekistan.  These fossils date from the very end of the Cretaceous, so the Japanese specimen is some sixty million years older.

High resolution X-ray computed microtomography was used to identify the shape of the bones which remain partially buried in the part-prepared fossil.

The Rock Containing the Partially Exposed Fossil Bones Along with a Computer Image Tracing the Outline of the Individual Bones

Fossils and computer enhanced image showing holotype of Shirerpeton.

A new Early Cretaceous amphibian from Japan (Shirerpeton).

Picture Credit: The Education Board of the city of Hakusan, (Ishikawa Prefecture, Japan)

Tiny Fossil

The picture (above) shows the holotype fossil of the new albanerpetontid amphibian, which has been named Shirerpeton isajii.  Image (A) shows the fossils in the 2.5 by 1.5 cm square slab of rock, whilst image (B), is a digital photograph with various bones from the skull highlighted.  Abbreviations: Br, braincase elements; Fr, frontal; L.La, left lacrimal; L.Mx, left maxilla; L.N, left nasal; L.Pa, left parietal; LPf, left prefrontal; L.Sm, left septomaxilla; L.Sq, left squamosal; R.La, right lacrimal; R.Pa, right parietal; R.Pf, right prefrontal; R.Sq, right squamosal; ?, unidentified element. Scale bars in both images = 5 mm.

Writing in the open-access academic journal PLOS One, the researchers, Susan Evans, a professor of vertebrate morphology and palaeontology (University College London) and Ryoko Matsumoto, a curator with the Kanagawa Prefectural Museum of Natural History were able to identify the specimen as a member of the Albanerpetontidae from the shape of the lower jaw.  The distinctive frontal bone of the skull, along with several other identified autapomorphies (unique traits), enabled the scientists to erect a new species.

Shirerpeton isajii

The scientists named the species in honour of Shinji Isaji, the head of the Tetori Group fossil investigation commission, a body under the Hakusan city government in charge of studying the Kuwajima fossil location where the fossil was found.

A spokesperson from Everything Dinosaur commented:

“There are about twenty of these amphibians known in the fossil record, currently assigned to five genera.  They were globally widespread during the Mesozoic, but this is the first time an albanerpetontid has been recorded from East Asia.  Their fragmentary record makes understanding their evolution and their phylogeny very difficult, scientists are not even sure how closely related these ancient lissamphibians are to extant amphibians.  Small animals like Shirerpeton are just as important as larger animals like dinosaurs when it comes to considering ancient environments and habitats.  In fact, this amphibian is probably more important than larger vertebrates in helping scientists to understand the localised climate in the Barremian of Japan.”

17 04, 2018

Out with a Bang, In with a Bang – The Story of the Dinosauria

By | April 17th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Mass Extinction Event Paved the Way for the Dinosaurs

It is now widely accepted that dramatic, global climate change played a significant role in the extinction of the non-avian dinosaurs some 66 million years ago.  The demise of the Dinosauria is well documented, but just how did this particular branch of the Archosauria rise to prominence and just as importantly, when did they start to dominate life on land?  There remains much to be learned about the origins of the dinosaurs, in addition, after the first dinosaurs evolved, for some 20 million years or so they made up only a tiny portion of terrestrial fauna, other reptiles dominated, then all of a sudden, at least when you consider the scale of geological time, the fossil record shows a change in the dinosaur’s fortunes.  From being bit-part players in the Middle Triassic, by the Late Triassic they had taken centre stage.

Research published in the journal “Nature Communications”, postulates that the first, rapid diversification of the dinosaurs occurred following a dramatic global ecosystem crisis.  This crisis was caused by rapid climate change, the ensuring mass extinction event cleared away a lot of competitors, especially herbivores.  A mass extinction event resulted in the demise of the dinosaurs, but it seems likely (according to this new research), that a mass extinction event led to their ascendancy in the first place.

Terrestrial Life Around 234-232 Million Years Ago

Late Triassic terrestrial fauna.

Life in the Late Triassic, an explosion in dinosaur diversity.

Picture Credit: Davide Bonadonna

The picture (above), shows a scene in the early Late Triassic of southern Pangaea around 232 million years ago.  On the far left a pair of Rhynchosaurs (diapsid, herbivorous reptiles characterised by stocky bodies, a squat gait and powerful beaks for cropping plants), lounge on a fallen tree.  In the centre background a large, carnivorous Rauisuchian is patrolling.  Rauisuchians  were Archosaurs, but on the other branch of the Archosauria – the Crurotarsi which comprise crocodile-like animals, as opposed to the second main branch of the Archosaurs the Avemetatarsalia, which houses the birds and the dinosaurs.  The Rauisuchian walks with an erect posture, (legs directly under the body).  In the foreground, two species of light-weight, bipedal early dinosaurs are depicted.

The Carnian Pluvial Episode (Carnian Pluvial Event)

The study conducted by Massimo Bernardi of the MUSE (Museo delle Scienze of Trento) and Piero Gianolla of the University of Ferrara (Italy) in collaboration with Professor Michael Benton of Bristol University, provides evidence to suggest that the diversification of the Dinosauria followed the Carnian Pluvial Episode, a time when the Earth went from an extremely arid climate to a humid and substantially wetter climate, before reverting back to arid once again.  This dramatic period in Earth’s history occurred between 234 and 232 million years ago (during the Carnian faunal stage of the Late Triassic).  The cause of this violent swing in our planet’s weather patterns is elusive, but most palaeontologists consider the huge volcanic eruptions in western Canada and the outpouring of vast quantities of igneous material, which are represented today by the great Wrangellia basalts as the engine for climate change.  What is termed Large Igneous Province (LIP) volcanism, resulted in huge amounts of carbon dioxide being released into the atmosphere.  This led to rapid, ocean acidification, increased rainfall and dramatic global warming turning a dry world dominated by large deserts in central Pangaea, into much more humid and wetter environments.

For Much of the Triassic the Land was Dominated by Deserts

Triassic landscape.

New study suggests the impact of the Carnian Pluvial Episode (CPE) gave dinosaurs the opportunity to diversify.

Dating Ichnoassemblages from the Dolomites

The researchers examined the ancient Triassic fauna of South America and compared these palaeoenvironments with data from the Italian Dolomites.  Although dinosaur and other reptile fossils from Triassic sediments are relatively widespread, for example Triassic vertebrate fossils are known from North America, South Africa, China, Europe and England, accurately dating these deposits has proved to be extremely difficult.  Hence the significance of the Italian Dolomites.  The stratigraphy of the Southern Alps and of the Dolomites in particular covers virtually the whole of the Middle and Late Triassic.  The sequence of strata, can be dated using a variety of methods, which when cross-referenced provides one of the most detailed geological timescales of the early Mesozoic anywhere on Earth.

Dating the Dolomites – A Bio-Chrono-Stratigraphic Framework

Dating the Dolomites.

Dating the Dolomites, a number of dating methods are available to scientists, permitting them to accurately date the rocks and the fossils they contain.

Picture Credit: Nature Communications/Bernardi, Gianolla, et al

Preserved in the rocks of the Dolomites are a series of tracks and trackways.  These footprints provide palaeontologists with an idea of the animals around at the time the sequence of strata was being laid down.  This research team noticed that prior to the Carnian Pluvial Episode, when this part of the world was arid, the tracks were dominated by Crurotarsi Archosaurs, in the early Carnian 100% of the tracks represent these crocodile-like reptiles.  However, during the Carnian Pluvial Episode (CPE), 50% of the tracks represent dinosaurs, whilst just 20% indicate the presence of Crurotarsi Archosaurs, the rest are associated with Dinosauromorphs, close relatives of the true dinosaurs.  As the world entered the Norian faunal stage of the Late Triassic, some 227 million years ago, nearly all the tracks preserved in this region (90% plus) were made by dinosaurs.

The complicated chart above, plots the occurrence of several precisely dated ichnoassemblages in the Late Triassic of the Southern Alps allowing the research team to date, relatively precisely, the timing of the diversification of the dinosaurs in this part of Pangaea.  On the left of the chart is the timeline in millions of years, the Period/Epoch and the faunal stage and sub-stage are noted.  Helping to relatively date the sequence of rocks are the zonal fossils, in this case ammonites, the rocks of this region can be mapped sequentially using key fossil ammonite species which provide a biostratigraphical reference.

The sequence of geological formations are shown and the various ichnotaxa associated with them are displayed.  The scientists identify the probable track maker and describe them as dinosaurs (sky blue), Dinosauromorphs (light green) or Crurotarsans (orange).  The length of the coloured column shows the time interval over which the tracks have been found.

Note the absence of dinosaur tracks in the Middle Triassic (bottom part of the chart), however, blue columns (dinosaur tracks) dominate the top part of the chart, the Late Triassic.  Pie charts show percentage breakdown of the different tracks, pre, during and post the CPE.  The final column on the far right provides details of the palaeoenvironment and the flipping from arid to humid and then back again.

Geological Formations Abbreviations: ADZ: Zoppè Sandstone; AQT: Acquatona Formation; BHL: Livinallongo/Buchenstein Formation; BIV: Bivera Formation; CTR: Contrin Formation; DCS: Cassian Dolomite; DON: Dont Formation; DPR: Dolomia Principale; FCL: Coll’Alto dark Limestones; GLS: Gracilis Formation; HKS: Heiligkreuz Formation; IMF: Fernazza Formation and volcanites; MBT: Ambata Formation; MNA: Moena Formation; MRB/RIC: Richthofen Conglomerate and Morbiac dark Limestone; NTR: Monte Rite Formation; PPS: Piz da Peres Conglomerate; REC: Recoaro Limestone; SCI: Sciliar Formation; SCS: San Cassiano Formation; SLI: Lower Serla Dolomite; SLS Upper Serla Formation; TVZ: Travenanzes Formation; VTG: Voltago Conglomerate; WEN: Wengen Formation.

The small boxes underneath the chart provide a key to the general characteristics of the rocks associated with each geological formation: (a) cherty limestone; (b) sandstone; (c) sandy limestone; (d) volcanics; (e) oolitic-bioclastic limestone; (f) black platy limestone or dolostone, black shale; (g) dolostone; (h) marlstone, claystone and shale; (i) marly limestone; (j) conglomerate.

In summary the lithology (characteristics of the rocks), the length of the sequence of deposition, helping to provide absolute dating information along with the abundance of zonal fossils to permit relative dating, allow scientists to accurately map the geological time represented by the strata.  This precise dating has enabled the researchers to tease out the significance of the CPE in reference to the evolution of the dinosaurs.

The Diversification of the Dinosaurs Coincides with the Carnian Pluvial Episode

The diversification of the dinosaurs.

The diversification of the dinosaurs coincides with the Carnian Pluvial Episode (CPE).

Picture Credit: Everything Dinosaur

Over a period of around 8 million years the palaeofauna of the southern Alps as shown by trace fossils changed dramatically.  Dinosaur trace fossils become much more abundant.  The researchers conclude that the dinosaurs diversified explosively in the mid Carnian, at a time of major climate and floral change and the extinction of key herbivores, which the dinosaurs opportunistically replaced.  The trace fossils found in the Dolomites region therefore play a crucial role in understanding the evolution of the Dinosauria.

Commenting on the significance of the study, one of the authors, Dr Piero Gianolla (University of Ferrara) stated:

“We had detected evidence for the climate change in the Dolomites.  There were four pulses of warming and climate perturbation, all within a million years or so.  This must have led to repeated extinctions.”

The discovery of the existence of a link between the first diversification of the dinosaurs and the CPE is unexpected and revolutionary.  This dramatic event not only paved the way for the dinosaurs to dominate terrestrial ecosystems, but also permitted the diversification of many other types of Tetrapod, including lizards, crocodiles, turtles and mammals, key terrestrial animals in today’s ecosystems.  The scientists conclude that they have developed a new framework for the evolution of the most famous reptiles.

The scientific paper: “Dinosaur diversification linked with the Carnian Pluvial Episode” by Massimo Bernardi, Piero Gianolla, Fabio Massimo Petti, Paolo Mietto and Michael J. Benton published in the journal “Nature Communications”.

15 04, 2018

The Lufengosaurus That Got Away

By | April 15th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Pathology Identified in Lufengosaurus Specimen

An analysis of a 200 million-year-old bite-mark has provided scientists with a detailed picture of a dinosaur’s life.  The bite-mark, preserved on the fossilised rib of a Lufengosaurus (L. huenei) may also provide a clue to how this member of the Sauropodomorpha met its end.  The specimen preserves evidence of an attack on a plant-eating dinosaur, probably from a Theropod and although the attack initially was not fatal, the resulting infection that occurred in the bone may have contributed to the unfortunate dinosaur’s death.

A Life Reconstruction of the Lufengosaurus Showing the Bitemark

Lufengosaurus with bite-mark (life reconstruction).

A life reconstruction of L. huenei in its natural environment and demonstrating the bite wound affecting the shoulder of the herbivorous dinosaur.

Picture Credit: Zongda Zhang

Employing an advanced X-ray technique, an international team of scientists from the UK, China, the United States and South Africa, have published evidence for an unsuccessful attack on a Jurassic dinosaur, a member of the Suborder Sauropodomorpha from China known as Lufengosaurus (L. huenei).  Everything Dinosaur was contacted by one of the authors of the scientific paper, published in the academic journal “Nature Scientific Reports”, a PNSO Lufengosaurus replica was purchased so that the model could be used to help explain the pathology and inferred animal behaviour from the scientific research.

The study provides a detailed report of the first recognised case of an abscess in a long-necked dinosaur from the Lower Jurassic of China, (Yunnan Province), which was caused by infection brought on from the bite of a large predatory dinosaur.  The infection may have weakened the animal, ultimately resulting in its death.

Scientist Lida Xing Holding the Damaged Rib Bone

Rib bone of Lufengosaurus showing pathology.

The pathological fossilised rib of Lufengosaurus huenei.

Picture Credit: Lida Xing

Micro-computed X-ray Tomography

The pathology, was discovered in the skeleton of a L. huenei, which is part of the vertebrate fossil collection at the Yuxi Museum (Yunnan Province).  The fossil rib bone was subjected to micro-computed x-ray tomography (micro-CT).   This permits high-resolution slices and three-dimensional images to be built up of internal structures of bone without damaging the fossil material.  It is a non-destructive research technique.  As well as providing detailed evidence of interactions between big, herbivorous dinosaurs and carnivorous Theropods, the successful identification of this abscess using this technique could point to a new understanding of where certain species lived, and the impact of the diseases that they suffered from.

Commenting on the significance of the research, one of the authors of the scientific paper, Dr Patrick Randolph-Quinney (University of Central Lancashire in the UK and the University of the Witwatersrand in South Africa), stated:

“We were able to use micro-CT to look deep inside the structure of the rib and visualise the precise changes that bacterial infection had caused, as well as to see the region of bone that had been bitten out of the rib.  What micro-CT is allowing us to do is understand processes such as trauma and infection in the fossil record at the cellular level, as well as looking at the whole bone.  This gives us advantages over traditional histology – which slices up bone for magnification under a microscope – in that it doesn’t require us to damage precious fossils and it also allows us to build 3-D reconstructions of the whole region of disease.  In this case, this has allowed us to model and study the whole wound track, not just a single portion of it.”

Images of the Rib Pathology

Lufengosaurus rib pathology caused by a bite.

A 3-D and 3-D slice reconstruction of the Lufengosaurus rib pathology.

Picture Credit: Patrick Randolph-Quinney (University of Central Lancashire)

The picture (above), shows a 3-D and 3-D slice reconstruction of the Lufengosaurus rib pathology.  Micro-computed tomography allowed the scientists to produce surface renderings of the fossil in 3-D (top row) and 2-D X-ray slices through the rib (bottom row).  These images show areas of cellular reorganisation, bone destruction and bone formation indicative of ostemyelitis (bone infection).

Lufengosaurus (L. huenei)

Lufengosaurus grew to about six metres in length.  It is estimated to have weighed around two tonnes.  More than two dozen specimens of this Prosauropod have been discovered to date, adults as well as fossil material from juveniles.  All the fossils ascribed to this genus have been discovered in the Lufeng Formation of south-western China (Yunnan Province).  Yang Zhongjian, known in western literature as Chung Chien Young, formally named and described Lufengosaurus in 1941.  Lufengosaurus was the first dinosaur from China to have been discovered, studied and displayed by Chinese scientists.

The PNSO Lufengosaurus Dinosaur Model Supplied to the Researchers by Everything Dinosaur

PNSO Lufengosaurus replica.

The PNSO Lufengosaurus dinosaur model.

Picture Credit: Everything Dinosaur

Lead author of the study, Dr Lida Xing (China University of Geosciences) added:

“This case is really exciting as it gives us evidence of interactions between large plant-eating dinosaur species and one of the large aggressive predators preying on them at that time.  Using the latest X-ray imaging we were able to track the changes in the bone caused by an infected bite on the Lufengosaurus, probably from a big carnivorous dinosaur.  We don’t just have evidence of disease but of behaviour between animals – between predator and prey at this deep period in prehistory.”

This study was carried out by researchers at the University of Central Lancashire (UCLan), China University of Geosciences, the University of the Witwatersrand in South Africa, the Carnegie Museum of Natural History in the USA, the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, and the Yuxi Museum, Yunnan, China.

The team were able to identify an infection in the bone called osteomyelitis which produces a pus-filled abscess inside the bone.  This is only the second time that a case of osteomyelitis has been recorded in the Sauropodomorpha, the other instance came from a giant Titanosaur from Argentina, the Lufengosaurus example pre-dates the Argentinian example by tens of millions of years.  It is the earliest recorded case of a bony abscess caused by osteomyelitis disease in the fossil  record.

Views of the Damaged Lufengosaurus Rib Bone

A damaged rib of a Lufengosaurus.

The pathological fossil rib (two views).

Picture Credit: Lida Xing

Hao Ran from the Kunming Institute of Zoology, Chinese Academy of Sciences, commented:

“This is a great example of how the clinical sciences and the science of palaeontology are working together with fossils from the Chinese fossil record.  Together with international collaborators we are able to advance our understanding of diseases in both the past and the present.  We don’t know which predator caused the bite, but we do have a smoking gun of the attack with the bite wound it left.”

The scientific paper: “Possible Bite-induced Abscess and Osteomyelitis in Lufengosaurus (Dinosauria: Sauropodomorph) from the Lower Jurassic of the Yimen Basin, China” by Lida Xing, Bruce M. Rothschild, Patrick S. Randolph-Quinney, Yi Wang, Alexander H. Parkinson and Hao Ran published in Nature Scientific Reports.

12 04, 2018

Why So Many Large Predators in Cretaceous Africa?

By | April 12th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Calcium Isotope Study Sheds Light on Lost World Dominated by Giant Predators

In the autumn of 2011, the BBC aired a new CGI-based dinosaur television series called “Planet Dinosaur”.  The first episode of this documentary series was entitled “Lost World” and focused on the remarkable fossil discoveries from Africa which shed light on ecosystems that seemed to be dominated by hypercarnivores (animals that have a diet that consists of more than 70 percent meat).  Viewers were introduced to giant meat-eating dinosaurs such as Carcharodontosaurus (C. saharicus) and the abelisaurid Rugops (R. primus) as well as super-sized, ancient crocodiles such as Sarcosuchus (S. imperator).  One of the questions posed in the television episode, was how could all these large predators co-exist?  Thanks to some fascinating research involving the study of vertebrate teeth from two famous African fossil deposits, scientists have been able to come with an answer.

Spinosaurus – Featured in Episode 1 “Lost World”

The front cover of the book "Planet Dinosaur"

The documentary series highlighted the latest research on the Theropod Spinosaurus.

Picture Credit: Everything Dinosaur/BBC

A study of calcium isotopes in fossil teeth suggests that some large, carnivorous Theropods (carcharodontosaurids and abelisaurids) preferred to hunt terrestrial prey such as herbivorous dinosaurs, whilst others such as spinosaurids were mainly fish-eaters (piscivores).  The giant crocodile Sarcosuchus had a diet somewhere in between, consuming both terrestrial and aquatic prey.

Studying Fossil Remains from Niger and Morocco

Writing in the journal “The Proceedings of the Royal Society B (Biology)”, the researchers studied calcium in fossil remains from the famous Kem Kem deposits of Morocco and the Gadoufaoua deposits of Niger.  The research was conducted by the Laboratoire de géologie de Lyon : Terre, planètes et environnement (CNRS/ENS de Lyon/Claude Bernard Lyon 1 University), in partnership with the Centre for Research on Palaeobiodiversity and Palaeoenvironments (CNRS/French National Museum of Natural History/Sorbonne University).

The team set out to try and understand why there were comparatively few herbivores recorded compared to the number of large carnivores represented in the fossil material.  The French scientists examined the vertebrate fossils from the Gadoufaoua region of central Niger (part of the Elrhaz Formation, which dates from the Late Aptian to Early Albian stages of the Early Cretaceous).  These fossils represent a flood plain ecosystem that existed some 115-112 million years ago.  Vertebrate fossils from the geologically younger Kem Kem Beds of south-eastern Morocco were also studied.

The Kem Kem deposits, sometimes referred to as the Continental Red Beds, because of the abundance of red sandstone sediments, are difficult to interpret due to the amount of mixing of fossil material and re-deposition.  Dinosaur fossils from this locality are approximately 100 million years old (Cenomanian faunal stage of the Late Cretaceous).  The two sites are characterised by the overabundance of predators compared to herbivorous dinosaurs and to determine why, the researchers measured the proportions of different calcium isotopes in the fossilised remains (fish scales and tooth enamel).

Examples of Vertebrate Teeth from the Gadoufaoua Deposits (Niger)

Calcium isotope study reveals diets of mid Cretaceous African vertebrates.

Teeth from vertebrates represented by mid Cretaceous fossil material (Kem Kem and Gadoufaoua deposits).  Scale bar = 2 cm.

Picture Credit: Auguste Hassler / LGL-TPE / CNRS-ENS de Lyon-Université Lyon

The picture above shows examples of various vertebrate teeth associated with the Gadoufaoua deposit.  From left to right Sarcosuchus imperator (giant crocodile), a tooth from an indeterminate spinosaurid, a tooth from a non-spinosaurid Theropod (abelisaurid or carcharodontosaurid), a pterosaur tooth, a tooth from a hadrosaurid dinosaur (herbivore), the rounded and flattened tooth associated with a pycnodont (fish) and the tooth of a small crocodylomorph.

Tell-Tale Calcium

Among vertebrates, calcium is almost exclusively derived from food.  By comparing the isotopic composition of potential prey (fish and herbivores), with that of the teeth of carnivores, it is possible to map the probable diet of those meat-eaters.  The researchers found that the data from the two locations showed similar results.  Some large, meat-eating dinosaurs such as the carcharodontosaurids and the abelisaurids preferred to hunt terrestrial prey, whilst spinosaurids displayed a very distinctive isotopic signature indicating a marked preference for aquatic prey (fish).  Sarcosuchus, on the other hand, may have been more of a generalist.  Calcium isotope data showed that these large crocodiles fed on terrestrial as well as aquatic animals.

The Skull  and Jaws of Sarcosuchus

Skull of Sarcosuchus.

The huge skull of Sarcosuchus – a giant crocodile that preyed on terrestrial as well as aquatic prey.

Picture Credit: Patrina Malone

Resource Niche Partitioning

This study suggests that predators avoided direct competition by sharing food resources.  The distinctive taxonomic clustering in calcium isotope values recorded by the French researchers strongly supports the idea of niche partitioning, that is, different types of carnivore used the resources in the environment differently which enabled them all to co-exist.  The calcium isotope measurements allow palaeontologists to examine feeding evidence across a food chain within an ecosystem.  This research, if applied elsewhere, such as within other fossil Lagerstätte, may permit clarification of food chain roles and niche partitioning within numerous ancient palaeoenvironments.

The scientific paper: “Calcium Isotopes offer Clues on Resource Partitioning among Cretaceous Predatory Dinosaurs” by A. Hassler, J. E. Martin, R. Amiot, T. Tacail, F. Arnaud Godet, R. Allain, V. Balter published in The Proceedings of the Royal Society B.

10 04, 2018

Single Bone Points Finger at Early Homo sapiens Migration

By | April 10th, 2018|Dinosaur and Prehistoric Animal News Stories, Main Page, Photos/Pictures of Fossils|0 Comments

Homo sapiens Spread Further Than Previously Thought – More Evidence

A single finger bone, measuring just 3.3 centimetres in length, indicates that modern humans were living in Saudi Arabia around 88,000 years ago.  The ancient digit, is the oldest human (H. sapiens), fossil to have been found to date outside of the cradle of humanity (Africa).  Its discovery suggests that early, modern humans travelled further than initially thought during the first reported human migration into Eurasia.  This fossil discovery adds to the evidence from Israel, China and Australia that Homo sapiens was widely dispersed outside of Africa as early as 180,000 years ago.

Views of the Ancient Human Finger Bone

Ancient human finger bone from Saudi Arabia.

Various views of the fossil intermediate phalanx from Saudi Arabia.

Picture Credit: Ian Cartwright

Excavating an Ancient Freshwater Lake Bed

Writing in the academic journal “Nature Ecology and Evolution”, the international team of researchers including scientists from the Max Planck Institute for the Science of Human History, the Saudi Commission for Tourism and National Heritage and Oxford University, report on the excavations of an ancient freshwater lake bed preserved in the Nefud Desert.  Prior to this and other recent discoveries, most palaeoanthropologists believed that early migrations out of Africa into Eurasia by H. sapiens had largely been unsuccessful, with early humans only reaching the relatively nearby Mediterranean forests of the Levant.

Fieldwork at the Al Wusta Site (Saudi Arabia)

Excavating the ancient lake bed in the Nefud Desert.

The Al Wusta excavation site, in the Nefud Desert (Saudi Arabia).

Picture Credit: Michael Petraglia/Max Planck Institute for the Science of Human History

Single Human Bone

The single human bone was subjected to CT scans to build up a three-dimensional image of the fossil.  It resembled a modern human finger bone, Neanderthal finger bones being shorter and squatter.  The fossil is described as an “intermediate phalanx”, it is the second furthest finger bone from the wrist.  In addition to the human fossil, the field team found evidence of the lush palaeoenvironment of the area including bones from a hippopotamus and the fossil shells of freshwater snails.  The scientists uncovered a large number of stone tools too.

88,000 Years Old

A dating technique called uranium series dating was used to estimate the age of the fossil.  A laser was employed to bore microscopic holes into the fossil bone and record the ratio between minute traces of radioactive elements.  Having compared the fossil to the digits of ancient hominins and primates, the scientists reported that this was conclusively a finger bone and it belonged to a member of our own species – Homo sapiens.

Lead author of the paper, Dr Huw Groucutt (Oxford University and the Max Planck Institute for the Science of Human History), stated:

“This discovery for the first time conclusively shows that early members of our species colonised an expansive region of southwest Asia and were not just restricted to the Levant.  The ability of these early people to widely colonise this region casts doubt on long held views that early dispersals out of Africa were localised and unsuccessful.”

Other dates obtained from associated fossil material and analysis of the ancient lake sediments corroborate the team’s findings.  The dates are focused on or around 90,000 years ago.  During this time the Al Wusta location looked very different than it does today.  The area was lush and green and the large lake was surrounded by a grassland ecosystem.

Co-author of the scientific paper, Professor Michael Petraglia (Max Planck Institute for the Science of Human History), added:

“The Arabian Peninsula has long been considered to be far from the main stage of human evolution.  This discovery firmly puts Arabia on the map as a key region for understanding our origins and expansion to the rest of the world.   As fieldwork carries on, we continue to make remarkable discoveries in Saudi Arabia.”

The Ancient Lake Bed (White) Surrounded by the Sand of the Nefud Desert

The prehistoric lake bed in the Nefud Desert.

Once this region was verdant with many lakes thanks to the monsoon rains.

Picture Credit: Michael Petraglia/Max Planck Institute for the Science of Human History

The scientific paper: “Homo sapiens in Arabia by 85,000 Years Ago” by Huw S. Groucutt, Rainer Grün, Michael D. Petraglia et al, published in the journal “Nature Ecology and Evolution”.

9 04, 2018

Late Triassic Giant Ichthyosaurs

By | April 9th, 2018|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Scientists Identify Giant Triassic Ichthyosaur Jaw Bone and Help Solve 19th Century Fossil Mystery

Scientists have identified a jaw bone of a giant marine reptile, that could represent one of the largest animals that ever lived.  The newly described fossil bones, representing a portion of an enormous lower jaw, may also have shed light on a mystery that dates back to the middle of the 19th Century.  The fossilised jaw, which consists of several, broken, individual pieces, is thought to be an incomplete surangular (bone from the rear of the lower jaw), from a shastasaurid Ichthyosaur, a clade of enigmatic, giant marine reptiles that were geographically widespread during the Late Triassic.  The fossil material was found on the beach at the small village of Lilstock in (west Somerset), the specimen is approximately 205 million years old.

A Lateral View of the Fossil Material – A Giant Ichthyosaur from Somerset!

Incomplete surangular from a giant Triassic Ichthyosaur.

The incomplete surangular jaw bone from Lilstock (Somerset).

Picture Credit: Manchester University

Found on a Somerset Beach

Fossil collector and co-author of the study, published in the scientific journal PLOS One, Paul de la Salle, found a portion of the specimen in May 2016.  He later returned to the beach and found more pieces, that together form a partial surangular more than a metre in length (see photograph above).

An Approximate Representation of the Location of Surangular on the Skull of Shonisaurus

The surangular bone of Shonisaurus is highlighted.

A close-up of the skull of Shonisaurus, the surangular bone is outlined in red.

Picture Credit: Scott Hartman with additional annotation by Everything Dinosaur

Commenting on his fossil find Paul stated:

“Initially, the bone just looked like a piece of rock but, after recognising a groove and bone structure, I thought it might be part of a jaw from an Ichthyosaur and immediately contacted Ichthyosaur experts Dean Lomax (Manchester University) and Professor Judy Massare (SUNY College at Brockport, New York, USA), who expressed interest in studying the specimen.  I also contacted Dr Ramues Gallois, a geologist who visited the site and determined the age of the specimen stratigraphically.”

Comparisons with Shonisaurus sikanniensis

Dean Lomax and Judy Massare made the surangular identification and visited the Royal Tyrrell Museum of Palaeontology in Drumheller, southern Alberta (Canada), to view skull material from the largest Ichthyosaur yet described, the monstrous shastasaurid Shonisaurus sikanniensis.  S. sikanniensis fossils come from Upper Triassic rocks found in British Columbia and the Royal Tyrrell material indicates a marine reptile around 21 metres in length.  The researchers found similarities between the new Somerset specimen and Shonisaurus sikanniensis, which suggests that the Lilstock fossils represent a giant shastasaurid too.

A Life Restoration and Skeletal Drawing of the Giant Ichthyosaur Shonisaurus

Shonisaurus life and skeletal reconstruction.

Shonisaurus life restoration and skeletal reconstruction (N. Tamura and S. Hartman).

Picture Credit: Nobumichi Tamura and Scott Hartman

As Big as a Blue Whale?

Commenting on the approximate size of the Somerset specimen, Dean Lomax said:

“As the specimen is represented only by a large piece of jaw, it is difficult to provide a size estimate, but by using a simple scaling factor and comparing the same bone in S. sikanniensis, the Lilstock specimen is about 25% larger.  Other comparisons suggest that the Lilstock Ichthyosaur was at least 20 to 25 metres.  Of course, such estimates are not entirely realistic because of the differences between species.  Nonetheless, simple scaling is commonly used to estimate size, especially when comparative material is scarce.”

When compared to giant marine vertebrates today, the upper end of the size estimate for the Lilstock specimen would indicate a creature longer than the largest toothed whale, the Sperm whale (Physeter macrocephalus), indeed, at around 25 metres long, it would rival in size the largest cetaceans of all, adult Blue whales (Balaenoptera musculus).

A Pair of Giant Shastasaurid Ichthyosaurs Cruise the Late Triassic Ocean with a Pod of Smaller Ichthyosaurs for Company

Shonisaurus illustrated.

A pair of Shonisaurus – giant marine reptiles of the Late Triassic.

Picture Credit: Nobumichi Tamura

Solving a Mystery That Dates Back to 1850

In 1850, a large bone was described from the Upper Triassic sediments of Aust Cliff in Gloucestershire (UK).  Four other fragmentary bone elements were subsequently found and described.  Sadly, two of these fossils are missing and presumed destroyed.  These bone shafts have been assigned to limb bones of herbivorous dinosaurs.  Two of the fossils were thought to resemble the limbs of Stegosaurs, but if that was the case, it would push back the evolutionary origins of Stegosaurs into the Norian faunal stage of the Late Triassic.  Other scientists have speculated that the fossil material might not be dinosaurian at all, but fossils of a related Archosaur from the pseudosuchian lineage.  However, with the discovery of the Lilstock specimen, another possibility has come to light.  These fossils could represent jaw fragments of giant, previously unrecognised Ichthyosaurs, after all, the Aust Cliff location has already yielded a number of marine reptile fossils including Ichthyosaurs.

Dean Lomax added:

“One of the Aust bones might also be an Ichthyosaur surangular.  If it is, by comparison with the Lilstock specimen, it might represent a much larger animal.  To verify these findings, we need a complete giant Triassic Ichthyosaur from the UK – a lot easier said than done!”

The scientific paper: “A Giant Late Triassic Ichthyosaur from the UK and a Reinterpretation of the Aust Cliff “Dinosaurian” Bones by Lomax, D. R., De la Salle, P., Massare, J. A. and Gallois, R. (2018) published in PLOS One.

5 04, 2018

180 Million-year-old Pregnant Ichthyosaur

By | April 5th, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page|0 Comments

Yorkshire and Pregnant Ichthyosaurs

Yorkshire might be famous for its beautiful countryside, its puddings and of course, its cricket team, but this part of England also has some remarkable geology.  Through the Vale of Pickering to the North Sea, there are magnificent exposures of Mesozoic-age rocks.  Parts of the Yorkshire coast are a haven for fossil hunters and much of the coastal area of “God’s own country”, as many Yorkshire residents call their county, provides the geological standard for comparing less well exposed areas inland and also for the geology of the North Sea basin.  Yorkshire Museum has recently opened permanent galleries that tell the amazing story of Yorkshire’s prehistoric past and a star exhibit is a fossil block that contains the remains of several Ichthyosaur embryos.

An Illustration of the Pregnant Ichthyosaur

Pregnant Ichthyosaur.

A pregnant pause in deep time. Fossilised Ichthyosaur embryos have been found in Yorkshire.

Picture Credit: Nobumichi Tamura (Manchester University)

Ichthyosaurs – Superbly Adapted Marine Reptiles

Ichthyosaurs were marine reptiles that superficially resembled dolphins.  They evolved during the Triassic and numerous different genera have been named.  Fossils of Ichthyosaurs have been found in many parts of the world, the first marine reptile to be scientifically described was an Ichthyosaur.  The fossilised remains were discovered at Lyme Regis on the Dorset coast and this animal was later identified as a specimen of a giant “fish lizard” known as Temnodontosaurus platyodon.  Superbly adapted to a marine existence, Ichthyosaurs had streamlined bodies, steered with their front flippers and propelled themselves through the water with their powerful tails.  These reptiles gave birth to live young (viviparous), rather than returning to land to lay eggs.

A Trio of Ichthyosaurs

Ichthyosaurs

Dolphin-like prehistoric animals, the Ichthyosaurs were a highly successful group of marine reptiles.

An Important Ichthyosaur Specimen

The Yorkshire Museum Ichthyosaur specimen, complete with the remains of between six and eight tiny embryos between its ribs, was collected from the Whitby area of North Yorkshire back in 2010.  We at Everything Dinosaur, suspect that the fossil was found in sediments that make up the Whitby Mudstone Formation.  The fossil was in the possession of a local collector, Martin Rigby, he thought the block could contain the remains of unborn Ichthyosaurs and this was confirmed when the specimen was examined by palaeontologists from the University of Manchester.   The specimen consists of a polished block which exposes several large ribs of the mother and numerous strings of tiny vertebrae and small bones that constitute the remains of the unborn “fish lizards”.  The fossil has been acquired by the Yorkshire Museum and forms an integral part of the Museum’s new permanent exhibition “Yorkshire’s Jurassic World”.

Rare British Fossil Revealing Embryos

Only five Ichthyosaur specimens from the British Isles have ever been discovered with embryos preserved and never before has a British Ichthyosaur fossil been found with so many.  All five known specimens were collected from Jurassic-aged rocks in the south-west of England, they are aged between 200 to 190 million years old.  However, the Yorkshire specimen, heralds from younger Jurassic sediments dating from the Toarcian faunal stage of the Early Jurassic.   It is around 180 million years old.

Commenting on the significance of the discovery Manchester University palaeontologist Mike Boyd, who along with colleague Dean Lomax, studied the specimen, stated:

“We also considered the possibility that the tiny remains could be stomach contents, although it seemed highly unlikely that an Ichthyosaur would swallow six to eight aborted embryos or new-born Ichthyosaurs at one time.  This does not seem to have been the case, because the embryos display no erosion from stomach acids.  Moreover, the embryos are not associated with any stomach contents commonly seem in Early Jurassic Ichthyosaurs, such as the remains of squid-like Belemnites”.

Eight different species of Ichthyosaur have been documented with embryos.  By far, the most commonly found Ichthyosaur genus with embryos is Stenopterygius.  Over a hundred specimens of Stenopterygius from the Holzmaden area of southern Germany have been found with embryos, ranging from one to eleven in number.

Co-author of the scientific paper and visiting scientist at the University of Manchester, Dean Lomax added:

“The German sites are approximately the same age as the new specimen from Whitby and it is possible that the new specimen is also Stenopterygius, but no identifiable features are preserved in the adult or embryos.  Nonetheless, this is an important find.”

A Cast of a Stenopterygius Specimen with an Embryo Expelled (Possibly Post Mortem)

Stenopterygius fossil.

Stenopterygius Ichthyosaur fossil originally from Germany.  Expelled embryo is indicated by the white arrow.

Picture Credit: Everything Dinosaur

Everything Dinosaur has been selected by the Yorkshire Museum to help supply prehistoric animal themed craft materials in support of the Museum’s outreach activities.  In addition, the UK-based company has supplied dinosaur and marine reptile themed merchandise to the Yorkshire Museum’s retail outlet.

Commenting on the permanent exhibition and the significance of the Manchester University research, a spokesperson from Everything Dinosaur stated:

“It is fantastic to see a museum celebrating the fossil heritage of Yorkshire and the research undertaken by the dedicated scientists at Manchester University has helped to give the opening of the permanent galleries even greater significance.”

The scientific paper: “The Youngest Occurrence of Ichthyosaur Embryos in the UK: A New Specimen from the Early Jurassic (Toarcian) of Yorkshire” by Boyd, M. J. and Lomax, D. R. (2018) published in the Proceedings of the Yorkshire Geological Society.

3 04, 2018

Isle of Skye Steps into the Jurassic Spotlight

By | April 3rd, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Middle Jurassic Dinosaur Tracks Put Skye Firmly on the Map

More evidence of Middle Jurassic dinosaurs on the Isle of Skye has emerged.  In a paper published in the Scottish Journal of Geology, a team of international scientists including researchers from the University of Edinburgh and the Chinese Academy of Sciences, report on a series of dinosaur prints and tracks from the Lealt Shale Formation (Bathonian faunal stage) of the Great Estuarine Group at Rubha nam Brathairean (Brothers’ Point), on the Trotternish peninsula (Isle of Skye).  Evidence of Middle Jurassic dinosaurs is globally rare, there are just a few fossil sites that provide information about terrestrial fauna that existed around 168 million years ago.  Trace fossils from the Isle of Skye are playing an increasingly significant role as palaeontologists seek to better understand the evolution and distribution of different types of dinosaur.

One of the Sauropod Prints at Rubha nam Brathairean

Sauropod track on the foreshore (Isle of Skye).

Sauropod track from the Isle of Skye.

Picture Credit: Jon Hoad

In 2015, Everything Dinosaur published an article featuring the discovery of a series of Sauropod prints and tracks found on northern Skye, at a locality close to Duntulm Castle (Duntulm Formation).

To read this article: Isle of Skye Sauropods and their Water World

Although, the Duntulm Castle site is just a few miles from the newly described trace fossils at Brothers’ Point and the strata in which the footprints and tracks were found are part of the Great Estuarine Group sequence of Middle Jurassic rocks, the two fossil sites represent different sub-units of strata.  The Lealt Shale Formation is geologically older than the fossiliferous rocks found at the Duntulm Castle site (Duntulm Formation).  Both locations represent a sequence of deposits made in brackish, lagoonal environments.  The fact that a second series of Sauropod tracks and prints have been found preserved in rocks laid down in a lagoon, strengthens the idea that Middle Jurassic Sauropods habitually spent time in these environments.  Could this indicate that at least some Middle Jurassic Sauropods were semi aquatic?

Did Middle Jurassic Sauropods Habitually Hang Out in Lagoons?

Isle of Skye Sauropods.

The Isle of Skye (Bathonian faunal stage).

Picture Credit: Jon Hoad

Around Fifty Footprints Measured and Studied

The researchers measured, photographed and analysed around fifty footprints in a tidal area.  Working conditions on the rugged headland were difficult, due to the tidal environment and the often, inclement weather for which, the Trotternish peninsula is famed.  Despite the harsh conditions, the scientists were able to identify two trackways and many examples of isolated prints.

The location preserves numerous small Sauropod manus (hand) and pes (foot) prints along with several isolated and broken medium-to-large tridactyl prints.  The three-toed (tridactyl) prints indicate the presence of Theropods (most probably carnivorous dinosaurs).  Measurements of the Sauropod tracks and stride lengths indicate that these trace fossils were made by relatively small members of the Sauropoda, the tracks indicate individuals around two metres high at the shoulders.  The Sauropod tracks, with their characteristic narrow gauge and toe morphology, have been tentatively assigned to the ichnotaxon Breviparopus.  The Theropod trackmaker remains equally enigmatic, however, some of the three-toed prints are reminiscent of the tracks associated with the ichnotaxon Eubrontes.

One of the Sauropod prints from the Lealt Shale Formation

Isle of Skye Sauropod footprint.

Sauropod footprint from the Isle of Skye.  The geological hammer and the pen provide scale (as do the copious gastropods).

Picture Credit: Paige dePolo (University of Edinburgh)

Commenting on the significance of this discovery, one of the authors of the scientific paper, Paige E. dePolo (University of Edinburgh) stated:

“This tracksite is the second discovery of Sauropod footprints on Skye.  It was found in rocks that were slightly older than those previously found at Duntulm on the island and demonstrates the presence of Sauropods in this part of the world through a longer timescale than previously known.  This site is a useful building block for us to continue fleshing out a picture of what dinosaurs were like on Skye in the Middle Jurassic.”

Co-author Dr Stephen Brusatte (University of Edinburgh), added:

“The more we look on the Isle of Skye, the more dinosaur footprints we find.  This new site records two different types of dinosaurs — long-necked cousins of Brontosaurus and sharp-toothed cousins of T. rex — hanging around a shallow lagoon, back when Scotland was much warmer and dinosaurs were beginning their march to global dominance.”

A Fossil Bias?

Although the discovery of a second site, demonstrating Sauropod tracks in a lagoonal depositional environment, raises the intriguing idea that these large, long-necked herbivores spent time in such environments, palaeontologists have to be careful what they infer from such data.  Sauropods may have spent much of their time in different habitats, such as forests, or perhaps, in more open environments such as fern prairies, however, in such environments the fossil preservation potential for things like tracks and footprints are that much lower.  Hence, the evidence for such behaviour may not exist, there could be a preservational bias in favour of recording Sauropod activity in brackish lagoons.  Thanks to this dedicated research team, more information has been obtained with regards to the Middle Jurassic palaeofauna of Scotland.  We look forward to future discoveries and fossil finds that will continue to inform the debate.

The scientific paper: “A Sauropod-dominated Tracksite from Rubha nam Brathairean (Brothers’ Point), Isle of Skye, Scotland” by Paige E. dePolo, Stephen L. Brusatte, Thomas J. Challands, Davide Foffa, Dugald A. Ross, Mark Wilkinson and Hong-yu Yi published in the Scottish Journal of Geology

“The Rise and Fall of the Dinosaurs” by Dr Steve Brusatte

One of the authors of this scientific paper (indeed one of the authors of the 2015, Duntulm Formation tracks research), Dr Steve Brusatte (School of Geosciences at Edinburgh University), has a new dinosaur book out next month.  Look out for the excellent “The Rise and Fall of the Dinosaurs” coming into shops in May.

New Dinosaur Book Out Very Soon

"The Rise and Fall of the Dinosaurs"

“The Rise and Fall of the Dinosaurs” by Steve Brusatte.

Picture Credit: Pan Macmillan

To read Everything Dinosaur’s recent book review: A Review of “The Rise and Fall of the Dinosaurs”

1 04, 2018

Updating Arkansaurus

By | April 1st, 2018|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Updating Arkansaurus fridayi

A few days ago, Everything Dinosaur published an article about the newly described basal ornithomimosaur called Arkansaurus fridayi.  Although the fossil bones were found nearly fifty years ago, the scientific paper describing the fossils and officially naming this dinosaur has only just been published (Journal of Vertebrate Palaeontology).  Lead author of the paper, ReBecca Hunt-Foster of the Bureau of Land Management, emailed us so that we could post up more images of this significant fossil discovery.

A Life Restoration of the Basal Ornithomimosaur Arkansaurus fridayi

A life restoration of Arkansaurus.

Arkansaurus fridayi life restoration.

Picture Credit: Brian Engh

To read Everything Dinosaur’s earlier article on the formal description of Arkansaurus: “Arkansas Reptile” – A Rare Insight into Appalachian Dinosaurs

More Primitive Than Asian Ornithomimosaurs That Lived at the Same Time

Ornithomimosaurs (the ostrich-mimic dinosaurs) are quite well known from the Early Cretaceous of Asia, however, very little is known about North American ornithomimosaurs from this time in Earth’s history, hence the importance of the Arkansaurus fossils.  The dinosaur has been named from a single, partial right foot, recovered from the Lower Cretaceous (Albian to Aptian faunal stages) of the Trinity Group of Arkansas.

A Cast of the Fossil Foot Bones (Anterior View)

Foot bones (Arkansaurus fridayi).

Arkansaurus fridayi foot bones (cast).

Picture Credit: R. Hunt-Foster

Contemporaneous with the likes of Beishanlong (B. grandis) from Gansu Province (north-west China), living around 113 million years ago, Arkansaurus fridayi can be distinguished from other ornithomimosaurs based on differences in the toe claws (pedal unguals) and the presence of a laterally compressed third metatarsal (toe bone) that is ovoid in shape when looked at in proximal view.  Other anatomical differences are cited by the researchers including a distal ungual with a very weak flexor tubercle, lacking spurs.

Two Views of the Metatarsal Bones of Arkansaurus

Fossil foot bones of Arkansaurus.

Views of the metatarsals of Arkansaurus.

Picture Credit: R. Hunt-Foster

The picture above shows two views of the toe bones (metatarsals)  of Arkansaurus (a) in proximal view, that is viewed from the top of the bone closest to the ankle looking down onto the bones and (b) anterior view, viewed from the front.  The third metatarsal is actually the bone in the middle.  The scientists conclude that the condition of the third toe bone suggests that Arkansaurus fridayi is more basal than Asian ornithomimosaurs of similar age, but consistent with older North American forms.

A Cast of the Fossil Toe and Claw Bones

Arkansaurus fridayi foot bones (a cast).

A view of a cast of the foot bones of Arkansaurus fridayi.

Picture Credit: R. Hunt-Foster

This specimen provides knowledge of a poorly understood radiation of ornithomimosaurs in the Cretaceous landmass known as Appalachia and is the only known Saurischian dinosaur fossil found to date in the state of Arkansas.

ReBecca Hunt-Foster Has Worked on These Fossils for Several Years

ReBecca Hunt Foster studying fossil bones

ReBecca Hunt-Foster examining limb bones (2003).

Picture Credit: R. Hunt-Foster

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