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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.

11 11, 2019

The First Unique Dinosaur Species from British Columbia

By | November 11th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Ferrisaurus sustutensis – Newest Member of the Leptoceratopsidae

This week has seen the announcement of a new species of horned dinosaur, a member of the Leptoceratopsidae and the first unique dinosaur species to be reported from the Canadian province of British Columbia.  The little dinosaur (estimated to be about 1.75 metres long and to have weighed around 150 kilograms), has been named Ferrisaurus sustutensis and it hints of an intriguing prehistoric fauna that roamed the more northerly and western portions of Laramidia around 67 million years ago.

A Life Reconstruction of the Newly Described Leptoceratopsid Ferrisaurus sustutensis 

Ferrisaurus sustutensis life reconstruction.

Ferrisaurus sustutensis illustrated.

Picture Credit: Raven Amos and courtesy of the Royal British Columbia Museum

First an Indeterminate Neornithischian

In 1971, construction workers building the now abandoned British Columbia Rail line close to the confluence of Birdflat Creek and the Sustut River in the Sustut Basin, discovered fragmentary bones in loose rubble.  At first the bones were thought to represent an indeterminate neornithischian dinosaur, but in this study undertaken by Dr Victoria Arbour (Royal BC Museum) and Dr David Evans (Royal Ontario Museum/University of Toronto), they have been assigned to the Leptoceratopsidae.  Leptoceratopsids were a family of hornless, parrot-beaked herbivores related to the Ceratopsidae, dinosaurs such as Triceratops and Styracosaurus.  These dinosaurs were restricted to the Late Cretaceous of the northern hemisphere, but there is some disputed fossil evidence to suggest a presence in Australia and in Europe too.

Dr Arbour Examining the Fossilised Remains of  Ferrisaurus sustutensis

Dr Arbour with the fossils of Ferrisaurus sustutensis.

Dr Victoria Arbour examines the fossilised remains of Ferrisaurus sustutensis.

Picture Credit: Brandy Yanchyk and courtesy of the Royal British Columbia Museum

Fossil remains include elements from the shoulder girdle, a complete left radius, a partial ulna along with hind limb bones, ankle bones and articulated toes from the right foot.  An as yet, unprepared block may also contain metatarsals from the left foot.  The researchers used the ulna (bone from the forearm) and compared it with other leptoceratopsids such as Leptoceratops (L. gracilis), Cerasinops (C. hodgskissi) and Montanaceratops (M. cerorhynchus).  They also examined the proportions of the toes and concluded, based on this assessment, that the fossilised remains represented a new genus, one that is phylogenetically firmly nested in the Leptoceratopsidae and probably quite closely related to Gryphoceratops morrisoni, which is known from the Dinosaur Provincial Park of southern Alberta.

Ferrisaurus sustutensis -What’s in a Name?

Ferrisaurus sustutensis (pronounced Fair-uh-sore-us suss-tut-en-sis), is the first unique dinosaur species reported from British Columbia and represents a western range extension for Laramidian leptoceratopsids.  The name translates as “the iron lizard from the Sustut River”, a reference to the location of the fossil discovery. When the fossil material was being prepared and studied the specimen was affectionately known as “Buster”.

Scientists are confident that more vertebrate fossil material will be found in the Upper Cretaceous rocks of the Sustut Basin, but there are problems with accessing and exploring this area.  As much of British Columbia is mountainous and forested, finding exposures of sedimentary rock to explore is challenging.  In 2017, Dr Arbour led a field team to the site and found fossilised plants and a fragment of a Cretaceous turtle (Basilemys).

Leptoceratopsid fossil material is quite rare and when these types of dinosaurs are found, they usually only represent a very small part of the dinosaur biota.  It is more usual for Upper Cretaceous, dinosaur fossil bearing strata to be dominated by duck-billed dinosaurs, horned dinosaurs or even tyrannosaurids.  Scientists have documented a preservational bias against small-bodied dinosaurs such as Ferrisaurus.  The first dinosaur to be described from the Sustut Basin might represent a fauna that was relatively unique to that part of Laramidia, or to find a leptoceratopsid dinosaur first, could simply be down to serendipity.

A Diagram Showing the Known Preserved Remains of Ferrisaurus sustutensis

Preserved elements of Ferrisaurus sustutensis.

Preserved elements of Ferrisaurus sustutensis (bones shaded grey represent missing parts of incomplete bones)

Picture Credit: PeerJ/Royal British Columbia Museum

The scientific paper: “A new leptoceratopsid dinosaur from Maastrichtian-aged deposits of the Sustut Basin, northern British Columbia, Canada” by Victoria M. Arbour and David C. Evans published in the journal PeerJ.

10 11, 2019

Superb Dinosaur Fossil Sheds Light on Triassic Terrors

By | November 10th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Gnathovorax cabreirai – Triassic Terror Sheds Light on the Origins of Predatory Dinosaurs

A number of revisions to the Dinosauria have occurred in recent years.  Perhaps most famously, by the 2017 scientific paper published by Baron, Norman and Barrett, that redefined the dinosaurs along the lines of a model proposed by Henry Govier Seeley back in the late 1880’s*.  In this study, the enigmatic and quite poorly known herrerasaurids (Herrerasauridae), with their confusing array of dinosaur and non-dinosaur anatomical traits, were not classified as theropods, instead they are placed on the branch of the family tree associated with the Sauropodomorpha.  This paper, therefore, suggested that meat-eating actually evolved twice, once in the herrerasaurids and then again in the Theropoda.

This scientific paper has certainly opened up the taxonomic debate, however, the discovery of a remarkably-well preserved skeleton of a herrerasaurid from southern Brazil has helped scientists to get a much better idea of the Herrerasauridae and this, in turn, has provided a new insight into how these reptiles fit into the wider Dinosauria picture.

Location Map and Geological Setting Plus Skeletal Drawing of the Newly Described Herrerasaurid Gnathovorax cabreirai

Location map, geological setting and skeletal reconstruction (Gnathovorax).

Location map of fossil find (A), along with geological setting and key to the bones of other vertebrates found in situ (B).  Skeletal reconstruction of Gnathovorax (C), the white bones in the skeletal drawing represent known fossil material.

Picture Credit: PeerJ

Hardly Known Herrerasauridae

Fragmentary fossils associated with possible members of the Herrerasauridae have been found in North America and Europe, but the three species of herrerasaurids that most palaeontologists agree upon (Herrerasaurus, Staurikosaurus and Sanjuansaurus) all herald from the Late Triassic of South America.  Trouble is, as a dinosaur family there is not a lot of fossil material to study.  Writing in the academic journal PeerJ, a team of scientists have published a paper on a new and exquisitely-preserved herrerasaurid that has been named Gnathovorax cabreirai.

Preserved in mudstone, this dinosaur roamed southern Brazil some 233 million years ago (Carnian faunal stage of the Triassic), it was found in an almost articulated state, just some bones from the limbs were missing.  It lay alongside rhynchosaur and cynodont fossil remains, animals that this 3-metre-long dinosaur probably hunted.

The new specimen sheds light into poorly understood aspects of the herrerasaurid anatomy, even permitting the researchers, which included scientists from the Universidade Federal de Santa Maria in Santa Maria, (Brazil), to piece together the animal’s brain, inner ear and cranial nerves.

Photographs of the Skull of  Gnathovorax cabreirai and Interpretative Line Drawings

Views of the skull material and interpretative line drawing.

Photographs and a line drawing of the skull of Gnathovorax.

Picture Credit: PeerJ

Finding a Place for the Herrerasauridae on the Dinosaur Family Tree

The researchers conclude that Gnathovorax provides enough evidence about the suite of anatomical traits associated with the Herrerasauridae to enable them to be placed with more confidence on the lizard-hipped part of the dinosaur family tree.  Thanks to Gnathovorax, the best-preserved herrerasaurid found to date, palaeontologists can state with more certainty that these early predatory animals were indeed members of the Dinosauria, part of the Saurischia along with the sauropodomorphs and the theropods.  Importantly, the fossil material is not distorted very much, which has permitted the team to conduct a phylogenetic analysis with a great deal of confidence as to the outcome.  Strangely,  Gnathovorax cabreirai is nested more closely to the Argentinean taxa of Herrerasaurus ischigualastensis and Sanjuansaurus gordilloi than it is to the only other herrerasaurid known from Brazil (Staurikosaurus pricei).  It reinforces the idea that herrerasaurids were monophyletic, that is, that all the dinosaurs classified in this family shared a common ancestor.  Therefore, the Herrerasauridae are proposed to be part of the saurischian Order of dinosaurs, along with theropods and sauropodomorphs, but importantly, distinct from both groups.  This new paper supports the idea that meat-eating evolved twice in the Dinosauria (herrerasaurids and theropods), just like the Baron, Norman and Barrett 2017 paper proposed, but it differs from this earlier publication in that it concludes that the Herrerasauridae were indeed true dinosaurs.

What’s in a Name?

The fossil material comes from the Santa Maria Formation (Rio Grande do Sul, Brazil) and is dated to circa 233.23 +/- 0.73 million years.  The genus name is from the Greek and is translated as “jaw that is inclined to devour”, a reference to the recurved teeth and the bodyplan of Gnathovorax that resembles a theropod dinosaur.  The species name honours Dr. Sérgio Furtado Cabreira, the palaeontologist that found the specimen described in the scientific paper.

The scientific paper: “Gnathovorax cabreirai: a new early dinosaur and the origin and initial radiation of predatory dinosaurs” by Cristian Pacheco, Rodrigo T. Müller​, Max Langer, Flávio A. Pretto, Leonardo Kerber and Sérgio Dias da Silva published in PeerJ.

*For Everything Dinosaur’s article on the Baron, Norman and Barrett paper: Root and Branch Reform for the Dinosaur Family Tree

7 11, 2019

Remarkable Fossil Ape from the Miocene of Southern Germany

By | November 7th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Danuvius guggenmosi – Adapted for Walking and Climbing

A previously unknown primate that lived in the forests of southern Germany around 12 million years ago was capable of walking upright, just like us.  Palaeontologists have debated how the development of bipedalism amongst the great apes occurred and for that matter, where in the world did the first apes capable of upright walking evolve.  A remarkable fossil found in Bavaria suggests that upright posture may have originated in a common ancestor of humans and great apes that lived in Europe and not in Africa as previously supposed.

A Life Reconstruction of the Newly Described Miocene Ape Danuvius guggenmosi

Danuvius guggenmosi life reconstruction.

Danuvius life reconstruction.

Picture Credit: Velizar Simeonovski / University of Tübingen

Writing in the publication “Nature”, an international research team led by Professor Madelaine Böhme from the Senckenberg Centre for Human Evolution and Palaeoenvironment (University of Tübingen), report on the discovery of a previously unknown type of primate that once roamed the forests of Bavaria.  This ape named Danuvius guggenmosi, which lived 11.62 million years ago, shows anatomical adaptations suited to both walking upright as well as using all four limbs for climbing.  The ability to walk bipedally with a plantigrade foot is considered a key evolutionary stage on the road that would eventually lead to the evolution of hominins including our own species H. sapiens.

The Twenty-one Fossils that Comprise the Male Danuvius Specimen

The 21 bones of the most complete partial skeleton of a male Danuvius.

The 21 bones of the most complete partial skeleton of a male Danuvius (D. guggenmosi).

Picture Credit: Christoph Jäckle / University of Tübingen

A Fossil That Resets the Evolutionary Clock

The scientists conclude that Danuvius were able to walk on two legs nearly twelve million years ago.  This is around six million years earlier than previously thought.  Up until this discovery the oldest evidence of potential bipedalism had been reported from Late Miocene of Africa and remarkably, from the island of Crete in the Mediterranean.  Close to the village of Trachilos in western Crete, scientists uncovered a series of footprints, the preserved tracks of an upright walking ape-like animal.  These trace fossils are believed to be around 5.7 million years old.  To read about these strange fossil tracks: Has Human Evolution Tripped Us Up?

The German fossil material represent a significant step (no pun intended), in terms of human evolution.  Lead author Professor Böhme explained:

“The finds in southern Germany are a milestone in palaeoanthropology, because they raise fundamental questions about our previous understanding of the evolution of the great apes and humans.”

Piecing Together the Skeleton of Danuvius (White Elements Represent Plaster Reconstructions of Bones)

Part of the reconstructed skeleton of Danuvius.

Reconstructing the skeleton of Danuvius.

Picture Credit: Christoph Jäckle / University of Tübingen

Lead Author of the Scientific Paper Professor Madelaine Böhme

Professor Madelaine Böhme (University of Tübingen)

Professor Madelaine Böhme examining the fossil material.

Picture Credit: Christoph Jäckle / University of Tübingen

How Did Hommins Come to Walk on Two Legs?

In the “Origin of Species” written by Charles Darwin and first published in 1859, one of the great controversies that arose from this book was the implications regarding our own evolution.  Darwin, perhaps all too aware of the seismic nature of his theory, did not dwell on this aspect of natural selection in his ground-breaking volume.  Towards the end of the book, in the concluding remarks section, he merely stated “light will be thrown on the origin of man and his history”.  Most of us now believe that we are descended from apes, however, one of the key distinguishing features between ourselves and the Great Apes, now bracketed in the same taxonomic family – the Hominidae, is that we walk on our hind legs and are truly bipedal, but how did this come about?  Did our bipedalism evolve from forest-dwelling monkey-like apes which clambered around on all fours?  Did bipedalism first arise in brachiating apes such as gibbons and orangutans who mostly use their arms to climb, or did it arise first in knuckle-walking apes such as bonobos, chimpanzees and gorillas?

Reconstructing Cranial Elements of Danuvius guggenmosi

Piecing together the skull and jaws of Danuvius.

A reconstruction of part of the skull and the jaws of Danuvius (white plaster indicates reconstructed elements).

Picture Credit: Christoph Jäckle / University of Tübingen

Mapping an Ancient Vertebrate Fauna Preserved in a Bavarian Clay Pit

The Danuvius guggenmosi fossils were discovered between 2015 and 2018.  Working in the Hammerschmiede clay pit in the Allgäu region of Bavaria, Böhme and her team excavated more than 15,000 fossil vertebrate bones from the ancient humid and forested ecosystems that were abundant in southern Germany at that time.  The new primate fossils include the remains of at least four individuals.  The most complete skeleton, of a male Danuvius, has body proportions similar to modern-day bonobos.  Thanks to completely preserved limb bones, vertebrae, finger and toe bones, the researchers were able to reconstruct the way Danuvius moved about in its environment.

Professor Böhme stated:

“For the first time, we were able to investigate several functionally important joints, including the elbow, hip, knee and ankle, in a single fossil skeleton of this age.  It was astonishing for us to realise how similar certain bones are to humans, as opposed to great apes.”

The scientists conclude that Danuvius was capable of walking on two legs but could also climb like an ape.  The spine, for example, had an S-shaped curve similar to our own spine, it held the body upright when standing on two legs.  The ape’s build, posture, and the ways in which it moved are unique among known primates.

Co-author of the paper, Professor David Begun (University of Toronto), commented:

“Danuvius combines the hindlimb-dominated bipedality of humans with the forelimb-dominated climbing typical of living apes.”

The male Danuvius stood about a metre in height and weighed approximately 31 kilograms.  Females were smaller, reflecting the sexual dimorphism found in the extant members of the Hominidae today.  The research team estimate that females weighed around 18 kg, less than any great ape alive today.  The ribcage of these apes was broad and flat.  The lower back was elongated; this helped to position the centre of gravity over extended hips, knees and flat feet, as in bipeds.  Several key-features of human bipedality have been found on bones from the leg.

The Hand Bones of the Male Danuvius in their Storage Boxes

Hand bones from the male Danuvius.

Bones from the hand of the male Danuvius (manus).

Picture Credit: Christoph Jäckle / University of Tübingen

Despite these human-like anatomical adaptations, Danuvius would have been very much at home in the trees, fellow researcher, Professor Nikolai Spassov of the Bulgarian Academy of Science highlighted that:

“In contrast to later hominins, Danuvius had a powerful, opposable big toe, which enabled it to grasp large and small branches securely”.

This new study supports a previously published paper that analysed a fossilised ape hip bone that was around ten million years of age, that had been found in Hungary.  The Hungarian and the German fossil material indicate that the European ancestors of African apes and humans differed from extant gorillas and chimpanzees.

The researchers point out that the ancestors we share with living African apes were as unique as we are today.  These fossils may help palaeoanthropologists to map out where in deep time the African apes and human ancestors diverged, these remarkable fossils from southern Germany are certainly a step in the right direction.

The scientific paper: “A new Miocene ape and locomotion in the ancestor of great apes and humans” by Madelaine Böhme, Nikolai Spassov, Jochen Fuss, Adrian Tröscher, Andrew S. Deane, Jérôme Prieto, Uwe Kirscher, Thomas Lechner and David R. Begun published in the journal Nature.

Everything Dinosaur acknowledges the assistance of a press release from the University of Tübingen in the compilation of this article.

5 11, 2019

Fossil Footprints Reflect Diverse Dinosaurs in South-western Alaska

By | November 5th, 2019|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Fossil Footprints Reflect Diverse Dinosaurs in South-western Alaska

Dinosaur fossils and their footprints have been found in Cretaceous-aged rocks in the American state of Alaska before.  Everything Dinosaur has produced a number of articles featuring fossil discoveries, many of which come from the Denali National Park area of the central part of the state.  However,  a new paper published in the journal PLOS One, provides an insight into the dinosaurs that roamed the south-western corner of the “Last Frontier” state.  The Late Cretaceous of the area of Alaska now known as the Aniakchak National Monument was dominated by duck-billed dinosaurs, but ankylosaurs, theropods and birds also lived in that part of the world.

A Digital Reconstruction of the Aniakchak National Monument in the Late Cretaceous

A landscape dominated by hadrosaurs but ankylosaurs were present too.

Numerous hadrosaur tracks have been found – both adults and juveniles.

Picture Credit: Karen Carr/PLOS One

The Late Cretaceous (Maastrichtian) Chignik Formation

The trackways, individual prints and other fossils, such as cycad leaves that indicate that around 70 million years ago, this part of Alaska was much warmer than it is today, provide palaeontologists with an insight into a high latitude, dinosaur dominated ecosystem.  These fossils may also provide some further evidence to help palaeontologists understand how dinosaurs migrated from Asia into the Americas.  Seventy-five new dinosaur footprints and trackways have been documented, more than ninety percent of which represent hadrosaurs.

Representative Hadrosaur Tracks

Hadrosaur tracks from Alaska.

Photographs of hadrosaur trackways including an overlapping track (A) with line drawing (B) and a photogrammatic contour map of a footprint (F).

Picture Credit: PLOS One

Co-author of the study, Dr Yoshitsugu Kobayashi (Hokkaido University Museum, Japan), stated:

“This study provides us a better understanding of the high-latitude dinosaur ecosystems of Alaska.  Such an understanding will help us address important questions such as did the dinosaurs survive the winters there and, if so, how did they survive?”

A Map Highlighting the Position of the Fossil Discoveries

Aniakchak National Park location and fossil sites.

A, Alaska.  Red star is location of Aniakchak National Park and Preserve.  Blue circles show location of dinosaur bonebeds on North Slope.  B, Drawing of Aniakchak National Park and Preserve.  The outcrop pattern for the Chignik Formation is shown in light green. Red rectangle outlines this study area.  C, Close-up diagram of study area showing Chignik Formation exposures in light green, restricted to shoreline.

Picture Credit: PLOS One

Ankylosaurs Present Too

Two tracks have been identified as having been made by armoured dinosaurs (ichnotaxon Tetrapodosaurus), both these tracks were found in fallen blocks and the largest of the footprints measures around 35 centimetres wide.  The impression of five digits in each of the tracks indicate that these prints represent tracks made by the forelimbs, not the four-toed back legs of armoured dinosaurs.

A Potential Ankylosaur Track – Aniakchak National Monument

Potentail Alaskan armoured dinosaur track.

Armoured dinosaur track (ichnotaxon Tetrapodosaurus).

Picture Credit: PLOS One with additional annotation by Everything Dinosaur

Avian and Non-Avian Theropods

The research team also identified a number of different sized tridactyl (three-toed), prints.  Two different types of bird track were identified in the study, along with a much larger single print that the scientists estimate was made by a theropod dinosaur around five to six metres in length.  The fossil print has been assigned to the ichnogenus Grallator.  The track suggests a large, predatory dinosaur and the team comment that the footprint is roughly around the track size that would have been made by the pygmy tyrannosaurid Nanuqusaurus hoglandi, which was named and described in 2014, from material found in the far north of Alaska (Prince Creek Formation).

A Large Three-toed Theropod Dinosaur Print (Aniakchak National Monument)

Large theropod track from south-western Alaska.

Large tridactyl track attributed to the ichnogenus Grallator from the Aniakchak National Monument location.

Picture Credit: PLOS One

The scientific paper: “Dinosaur ichnology and sedimentology of the Chignik Formation (Upper Cretaceous), Aniakchak National Monument, south-western Alaska; Further insights on habitat preferences of high-latitude hadrosaurs)” by Anthony R. Fiorillo, Yoshitsugu Kobayashi, Paul J. McCarthy, Tomonori Tanaka, Ronald S. Tykoski, Yuong-Nam Lee, Ryuji Takasaki and Junki Yoshida published in the journal PLOS One.

Everything Dinosaur acknowledges the assistance of a press release from the Perot Museum of Nature and Science in the compilation of this article.

4 11, 2019

The First Pliosaur from Poland

By | November 4th, 2019|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Polish Giant Marine Reptile Found in Cornfield

A pair of Polish palaeontologists have published a scientific paper describing the discovery of a large, Late Jurassic pliosaur from a site located in a cornfield in the north-eastern part of the Holy Cross Mountains close to the village of Krzyżanowice in southern Poland.  This is the first pliosaur to have been found in Poland.  Scientists are puzzled with regards to the vertebrate fauna identified at the site, the pliosaur fossils are very similar to pliosaur remains associated with the Late Jurassic Boreal/Sub-Boreal localities of the Kimmeridge Clay in England and the Svalbard Archipelago in the Arctic.  However, the fossils of turtles and marine crocodiles found at this location have more in common with the fauna associated with ecosystems found much further to the south.

Teeth and a Partially Preserved Jaw of the Polish Pliosaur

Teeth and a partial jaw of the Polish pliosaur.

A photograph show a partial preserved jaw of the Polish pliosaur and fossil teeth.

Picture Credit: Polish Academy of Sciences

Fearsome Pliosaurs

The Pliosauridae are a family of marine reptiles within the clade Plesiosauria.  They are often referred to as the “short-necked plesiosaurs”, as unlike plesiosaurs, these reptiles evolved massive skulls on short, powerful necks.  Pliosaurs were geographically widespread throughout the Jurassic and Cretaceous with fossil discoveries having been made in Europe, including the UK, Australia, and the Americas.  It is believed they originated in the Early Jurassic and survived into the Late Cretaceous.

A Typical Pliosaur – Pliosaurus

CollectA Deluxe 1:40 scale Pliosaurus marine reptile diorama.

The CollectA Deluxe 1:40 scale Pliosaurus marine reptile model.

Picture Credit: Everything Dinosaur

A Ten-metre-long Giant

The fossilised remains, although fragmentary, suggest an animal around ten metres in length.  The presence of such a large, apex predator indicates that the ecosystem was particularly rich and diverse.  The pliosaur has yet to be scientifically described but it is very likely a new genus.  It swam in the warm, tropical sea in the central portion of the European archipelago, as during the Late Jurassic, sea levels were much higher and western Europe consisted of a series of large islands surrounded by a shallow sea.

Examining the Fossilised Bones and Teeth

Examining the pliosaur fossils.

Palaeontologist Dr Daniel Tyborowski (from the Museum of the Earth of the Polish Academy of Sciences) in Warsaw and co-author of the scientific paper examines the fossil remains.

Picture Credit: Polish Academy of Sciences

Identifying a Late Jurassic Faunal Boundary

The unusual mix of vertebrate fossils, some similar to animals that lived further north, whilst others resemble marine animals that lived in more southerly palaeolatitudes, has led the researchers to suggest that the fossils preserved in this part of Poland represent an ancient faunal boundary.  A faunal boundary is an area of demarcation between two ecosystems that are similar but contain different members.

The unique composition of the Krzyżanowice-site vertebrate fauna demonstrates that, during the Late Jurassic this new locality was located in the transitional palaeobiogeographic line referred to in the scientific paper as the “Matyja-Wierzbowski Line”.  The fossils represent the boundary between two ecosystems, an area where some faunal mixing between the two ecosystems occurred.

Identifying the “Matyja-Wierzbowski Line” in the Upper Jurassic Marine Deposits of Europe

Identifying the Identifying the “Matyja-Wierzbowski Line” - a faunal boundary.

Identifying the “Matyja-Wierzbowski Line”.  The black line plots the boundary between the two marine ecosystems.

Picture Credit: Polish Academy of Sciences with additional annotation by Everything Dinosaur

For a more in-depth explanation of faunal boundary, please refer to this article that discusses “The Wallace Line”, a faunal boundary in south-east Asia proposed by the English biologist Alfred Russel Wallace: New Species of Rat Discovered in Sulawesi.

The scientific paper: “New marine reptile fossils from the Late Jurassic of Poland with implications for vertebrate faunas palaeobiogeography” by Daniel Tyborowski and Błażej Błażejowski published in the Proceedings of the Geologist’s Association.

3 11, 2019

New Megaraptorid Dinosaur from the Lower Cretaceous of Australia

By | November 3rd, 2019|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Fossil Bones Unearthed in Victoria Resemble Australovenator

Scientists have announced the discovery of several isolated theropod dinosaur bones, including a vicious 20 centimetre long hand claw discovered on the Otway Coast of Victoria (Australia).  The fossil material is reminiscent of Australovenator wintonensis, a megaraptorid dinosaur known from the Winton Formation of Queensland.  The finding of these new meat-eating dinosaur fossils in Victoria suggests that the Megaraptoridae were both geographically and temporally widespread in Australia.

The Fossilised Hand Claw of a Megaraptorid Dinosaur

Dinosaur hand claw from Victoria.

Ungual phalanx ascribed to a megaraptorid dinosaur from Victoria (Australia).

Picture Credit: Stephen Poropat (Museums Victoria)

Fossils from the Eumeralla Formation

Writing in the academic “Journal of Vertebrate Paleontology”, the researchers, which included scientists from Museum Victoria, the Australian Age of Dinosaurs Natural History Museum and Swinburne University (Victoria), report the discovery of two teeth, two manual unguals, and a right astragalus that are almost identical to the corresponding elements in Australovenator.  The fossils come from the Eric the Red West (ETRW), site on Cape Otway, some fifty miles to the west of Port Phillip Bay.  The strata at this location is part of the Eumeralla Formation and dates from the lower Albian of the Early Cretaceous.  This suggests that the dinosaur that possessed that formidable hand claw roamed southern Australia around 107 million years ago.

In contrast, Australovenator wintonensis is known from the Winton Formation of Queensland (Cenomanian–lowermost Turonian faunal stages of the Cretaceous), as such, Australovenator roamed more than a thousand miles further north and lived at least ten million years later.

A Scale Drawing of Australovenator wintonensis

Drawing of Australovenator

Vicious dinosaur from “Down Under” – megaraptorid theropod dinosaurs from Australia including Australovenator wintonensis.

Picture Credit: Everything Dinosaur

The new Victorian specimens were discovered between 2011 and 2017, by volunteers working on annual Dinosaur Dreaming team’s excavations.  These digs are held each February and are coordinated by husband and wife palaeontologists, Swinburne’s Professor Patricia Vickers-Rich and Dr Thomas Rich from Museums Victoria, who are both co-authors of this new scientific paper.

Implications for “Australian Spinosaurs”

In this newly published paper, the researchers also reappraise the single neck bone (cervical vertebra), found along this coast and described as a possible spinosaurid bone.  In the light of this very much older (than previously known from Australia), megaraptorid fossil material, the researchers conclude that the neck bone described in 2011 as potentially Australia’s first member of the Spinosauridae, also probably represents Megaraptoridae fossil material.

To read about this neck bone: Is this Fossil Evidence of Australia’s First Spinosaurid?

Hunting Ornithopods

The Otway Coast area of Victoria has revealed evidence of the presence of many different types of ornithopods.  For example, last year we reported on the naming of Diluvicursor pickeringi.  It can be speculated that megaraptorid dinosaurs may have specialised in hunting the many different kinds of fast-running, herbivorous dinosaur that shared the rift valley that was opening up between Antarctica and Australia.

Prey for Megaraptorid Dinosaurs?

Diluvicursor pickeringi illustrated.

A pair of Diluvicursor dinosaurs feeding next to a fast running river in the Antarctica/Australia rift valley 113 million years ago.

Picture Credit: P. Trusler

The new theropod fossils were found isolated rather than as part of a single skeleton.  This is because they were carried some distance from where the theropods died by ancient, deep, fast-flowing rivers.  These rivers snaked through the then-narrow rift valley (now called the Bass Strait), that opened up as the supercontinent Gondwana gradually broke apart and separated.

Lead author of the study Dr Stephen Poropat (Swinburne Museum), commented:

“The similarities between the Victorian megaraptorid remains and Australovenator are striking.  If we had found these theropod bones in Queensland, we would probably have called them Australovenator wintonensis.  But they’re from Victoria, which prompts the question: Could one dinosaur species exist for more than ten million years, across eastern Australia?  Maybe.”

The scientific paper: “New megaraptorid (Dinosauria: Theropoda) remains from the Lower Cretaceous Eumeralla Formation of Cape Otway, Victoria, Australia” by Stephen F. Poropat, Matt A. White, Patricia Vickers-Rich and Thomas H. Rich published in the Journal of Vertebrate Paleontology.

Everything Dinosaur acknowledges the assistance of a press release from Swinburne University in the compilation of this article.

28 10, 2019

The Rise of the Mammals – Remarkably Quickly

By | October 28th, 2019|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Photos/Pictures of Fossils|0 Comments

Remarkable Fossil Treasure Trove Plots Recovery after Dinosaur Demise

Corral Bluffs, a dry and somewhat dusty region some sixty miles south of the Denver Museum of Nature and Science did not look all that promising when visited by Ian Miller and Tyler Lyson on one of their many field trips out from the Museum when they visited the site back in 2014.  The strata associated with this part of central Colorado, just to the east of the city of Colorado Springs, represents and almost uninterrupted depositional sequence from the Maastrichtian faunal stage of the Cretaceous to the Danian of the Palaeocene, a time of great faunal and floral turnover on our planet with the End-Cretaceous mass extinction event.

A View of the Corral Bluffs (Central Colorado)

Corral Bluffs - Colorado.

Corral Bluffs – Colorado and important site for Palaeocene mammal fossils.

Picture Credit: Denver Museum of Nature and Science/HHMI Tangled Bank Studios

Given the age of the sedimentary rocks, this site should yield important information on how terrestrial life recovered after the Chicxulub impact event, however, fossils proved elusive until the field team members literally hit upon the idea of cracking open the various, small, hard concretions associated with the site.  Many of the concretions contained fossils, including the preserved skulls of numerous mammals.  The subsequent treasure trove of plant and animal fossils excavated from the site have provided palaeontologists with a detailed chronology of how plant and mammalian life recovered from the mass extinction event.

Many Hard Nodules (Concretions) Contain Fossil Remains

Cracking a Corral Bluffs concretion.

Cracking open a concretion from the Corral Bluffs site.

Picture Credit: Denver Museum of Nature and Science/HHMI Tangled Bank Studios

One or two firm blows with a sturdy geological hammer and the concretion will reveal its treasure, more than a dozen genera of prehistoric mammal have been recorded from the site.

Once Open the Contents of the Concretion are Revealed

A concretion that has been cracked open.

A concretion is opened (Corral Bluffs site).

Picture Credit: Denver Museum of Nature and Science/HHMI Tangled Bank Studios

In addition to the academic paper published in the journal “Science”, a television documentary programme is being broadcast in America on the 30th October – “Rise of the Mammals” streaming on PBS).  A special exhibition entitled “After the Asteroid: Earth’s Comeback Story” has already opened at the Denver Museum of Nature and Science, visitors will be able to view some of the thousands of plant fossils that have been found.  These fossils document how flora recovered after the bolide impact that saw the demise of the Dinosauria.

The Exhibition will Include Many of the Plant Fossils Found at the Site

Plant fossils from Corral Bluffs - Colorado.

Thousands of plant fossils have been found.

Picture Credit: Denver Museum of Nature and Science/HHMI Tangled Bank Studios

After an initial “fern spike”, the scientists were able to plot the rise of forests dominated by palms, then the emergence of legumes with the introduction of a wider variety of trees over hundreds of thousands of years.  Pollen grain analysis, analysis of mineral radiometric decay from two volcanic ash deposits associated with the site, along with data from magnetostratigraphy enabled the researchers to date quite accurately the age of the layers that contained fossil material.

At first mammals were no bigger than rats, with the largest specimens estimated to weigh around 600 grammes.  However, within three-quarters of a million years many more species of mammal had evolved, the largest of which would have weighed around 50 kilograms.

George Sparks the President and CEO of the Denver Museum of Nature and Science, commented:

“Thanks to the expertise, vision and grit of the scientific team, we are gaining a clear understanding of how our modern world of mammals arose from the ashes of the dinosaurs”.

Numerous Mammal Skulls Have Been Found at the Corral Bluffs Location

Dozens of skull fossils from ancient mammals.

Many different types of prehistoric mammal have been identified from fossil skulls.

Picture Credit: Denver Museum of Nature and Science/HHMI Tangled Bank Studios

The Corral Bluffs Location Maps the Change in Flora and the Increase in Size of Palaeocene Mammals

Corral Bluffs timescale.

A timescale showing the change in flora and body size of Palaeocene mammals.

Picture Credit: Denver Museum of Nature and Science

Everything Dinosaur acknowledges the assistance of a press release from the Denver Museum of Nature and Science in the compilation of this article.

24 10, 2019

First Vertebrates Capable of Walking on Land May Have Never Left the Water

By | October 24th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles|0 Comments

Parmastega aelidae – Hunting Like a Crocodile

A fascinating new paper has just been published in the journal “Nature” that suggests that some of the very first animals with backbones that were capable of terrestrial locomotion may have never left the water.  Instead, these creatures distantly related to animals that walk on land today, including ourselves, hunted rather like extant crocodiles and ambushed animals on the shore.  That is the conclusion of a group of international scientists that have studied the fossils of Parmastega aelidae, a needle-toothed early tetrapod that lived around 372 million years ago.

A Tropical Lagoon 372 Million Years Ago – P. aelidae Hunting Behaviour

Parmastega aelidae life reconstruction.

Sosnogorsk lagoon with Parmastega aelidae hunting behaviour.  The image (above) shows a tropical coastal lagoon at Sosnogorsk in Russia, about 372 million years ago.  The lagoon is inhabited by various kinds of fish, but also by the early tetrapod Parmastega.  One of creatures – which had eyes positioned at the top of their heads – can be seen on the bottom, with another in the foreground diving down from the surface (with bubbles).  A few more are shown in the middle distance resting at the surface with their eyes above the water, and one in the background crawling onto the beach.  In the far distance, a storm is approaching from the sea.  The sediment in which the fossil bones are found seems to have been deposited during a storm event that killed the inhabitants of the lagoon.

Picture Credit: Mikhail Shekhanov for the Ukhta Local Museum

What are Tetrapods?

Tetrapods include all living and extinct amphibians, reptiles, birds and mammals.  They are predominantly terrestrial, although some animals, whales for example, are entirely marine but had land-living ancestors.  Most tetrapods have four limbs, although some such as snakes have lost their limbs, but evolved from four-limbed ancestors.  These types of animals evolved from lobe-finned fishes (Sarcopterygii), during the Middle to Late Devonian.  Recent fossil discoveries have greatly increased the number of tetrapods known from Upper Devonian strata, but most genera are still only described from very fragmentary remains.  Most of what palaeontologists know about this extremely important group of vertebrates is based on the better known and more complete fossil specimens representing Ichthyostega and Acanthostega.

A Life Reconstruction of the Late Devonian Tetrapod Ichthyostega

Ichthyostega life reconstruction.

Ichthyostega – life reconstruction.

Picture Credit: Julia Molnar

A Gap in the Fossil Record

Trouble is, both Ichthyostega and Acanthostega along with the less complete but partly reconstructable genera Ventastega and Tulerpeton date from around 365-359 million years ago (late Famennian age of the Devonian), but palaeontologists have found tantalising fragmentary fossils that are at least ten million years older and the oldest known tetrapod footprints date from nearly 395 million years ago – read about their discovery here: Footprints from a Polish Quarry Suggest Land Vertebrates 35 Million Years Earlier than Previously Thought.

In this newly published paper, the researchers that include Jennifer Clack (University of Cambridge) and Pavel Beznosov (Russian Academy of Sciences), describe Parmastega aelidae, a tetrapod from Russia dated to the earliest Famennian age (about 372 million years ago), represented by three-dimensional material that enables the reconstruction of the skull and shoulder girdle.  The raised orbits, lateral line canals and weakly ossified postcranial skeleton of P. aelidae suggest a largely aquatic, surface-cruising animal.  Phylogenetic analysis supported by Bayesian statistics indicates that Parmastega might represent a sister group to all other tetrapods.

Skull Bones of Parmastega – Numerous Skull Bones Have Allowed Palaeontologists to Reconstruct the Skull

Skull bones of Parmastega.

Diagrammatic images showing the associated bones (in orange) of two individual skulls associated with Parmastega.  Fossil material includes several examples of skull bones from individuals which permitted scientists to reconstruct the skull in great detail.

Picture Credit: Nature

Large, Narrow Teeth and a Crushing Bite – Comparisons with a Crocodile

The fossil material representing several individual animals comes from north-western Russia.  This area in the Late Devonian was a large tropical lagoon on a coastal plain, inhabited by many types of ancient fish including placoderms.  The unusual suite of anatomical features identified in Parmastega include elasticated jaws, slender needle-like teeth and eyes located towards the top of the head so that it could keep a look out for prey whilst remaining almost totally submerged.  These anatomical features are reminiscent to those found in today’s aquatic ambush predators such as crocodilians.

Comparing the Skull of Parmastega to that of a Caiman

Parmastega compared to a Caiman.

The head of Parmastega compared to a modern crocodile.

Picture Credit: Nature

The scientists also discovered that part of Parmastega’s shoulder girdle consisted of cartilage, and its vertebral column and paired limbs could also be made of cartilage, indicating it probably spent most or all its time in water.  The large concentration of the fossil remains also suggests that it may have lived in large groups.

Co-author of the scientific paper, Professor Per Ahlberg (University of Uppsala, Sweden) stated that clues as to the lifestyle of Parmastega were found by analysing sensory canals identified in the fossil bones.  These sensors probably helped Parmastega to detect vibrations in the water, a trait inherited from its sarcopterygian ancestors.

Professor Par Ahlberg stated:

“These canals are well developed on the lower jaw, the snout and the sides of the face, but they die out on top of the head behind the eyes.  This probably means that it spent a lot of time hanging around at the surface of the water, with the top of the head just awash and the eyes protruding into the air.  We believe there may have been large arthropods such as millipedes or ‘sea scorpions’ to catch at the water’s edge.  The slender, elastic lower jaw certainly looks well-suited to scooping prey off the ground, its needle-like teeth contrasting with the robust fangs of the upper jaw that would have been driven into the prey by the body weight of Parmastega.”

Dr Marcello Ruta from the University of Lincoln, a co-author of the paper added:

“These fossils give us the earliest detailed glimpse of a tetrapod: an aquatic, surface-skimming predator, just over a metre in length, living in a lagoon.  The evolution of tetrapods is one of the most important events in the history of backboned animals, and ultimately led to the appearance of our own species.  Early in their history, tetrapods evolved many changes in their feeding strategies, movement abilities, and sensory perception, but many of these are still shrouded in mystery.”

Comparing the Head Morphology of Late Devonian Tetrapods

Late Devonian tetrapods.

Silhouette views of known Late Devonian tetrapods in approximate scale with head shape indicating different ecological niches.  Parmastega aelidae is estimated to be around a metre in length.

Picture Credit: Nature

Everything Dinosaur acknowledges the assistance of a press release from the University of Lincoln in the compilation of this article.

The scientific paper: “Morphology of the earliest reconstructable tetrapod Parmastega aelidae” by Pavel A. Beznosov, Jennifer A. Clack, Ervīns Lukševičs, Marcello Ruta and Per Erik Ahlberg published in the journal Nature.

20 10, 2019

Trilobite Fossils From Morocco Reveal Collective Behaviour

By | October 20th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Linear Clusters of Trilobites (Ampyx priscus)

Collective behaviour is seen in all kinds of animals today.  Birds migrating, plagues of locusts, turtle nesting behaviour, social insects and such like, but when and how such complex collective behaviour in the animal kingdom evolved remains a mystery.  A team of scientists writing in the academic journal “Scientific Reports”, have published a paper on a series of fossils from south-eastern Morocco, that have been interpreted as showing collective, social behaviour amongst a group of 480-million-year-old trilobites.

Trilobite Fossils from the Lower Ordovician – Possible Collective Behaviour

Trilobite collective behaviour.

The raphiophorid trilobite Ampyx priscus from the Lower Ordovician, Fezouta Shale of Morocco – collective behaviour.

Picture Credit: Scientific Reports

Trilobites Travelling in Columns

Social behaviour is seen in many arthropods and other types of invertebrate today.  Termites and ants living in colonies, communities of bees and wasps and many types of crustacean migrate in cohorts gaining protection against predators by their sheer weight of numbers.  For example, hundreds of spiny lobsters line up for their annual migration through the blue waters of the Caribbean.  Each lobster maintains contact with the one in front with its antennules and the anterior legs.  Thus, even at night the migration can continue without disruption.  The scientists have interpreted a series of fossils showing linear clusters of Ampyx trilobites as collective behaviour.  The fossils come from the Fezouta Shale (upper Tremadocian-Floian stage) and consequently are dated to around 480 million years ago.

Passive transport of the corpses of these ancient arthropods has been discounted by the researchers, instead, they conclude that this trilobite was probably migrating in groups and using its long spines to maintain a single-row formation.  Physical contact might have been reinforced with chemical communication, which is known to occur in some types of arthropods today.

This group behaviour may have been a response to environmental stress due to periodic storms shown by sedimentological evidence associated with the fossil deposits, or perhaps these animals were migrating together to reach favoured spawning grounds.

This record of linear clustering in early euarthropods suggests that intraspecific group-level patterns comparable to those of modern animals already existed 480 million years ago in the early stages of the Great Ordovician Biodiversification Event.

Interpretative Line Drawings of Trilobite Linear Clusters

Trilobite linear clusters.

Line drawings of trilobite linear clusters indicating collective behaviour.

Picture Credit: Scientific Reports

The scientific paper: “Collective behaviour in 480-million-year-old trilobite arthropods from Morocco” by Jean Vannier, Muriel Vidal, Robin Marchant, Khadija El Hariri, Khaoula Kouraiss, Bernard Pittet, Abderrazak El Albani, Arnaud Mazurier and Emmanuel Martin published in Scientific Reports.

19 10, 2019

How Did Big Dinosaurs Keep Cool?

By | October 19th, 2019|Dinosaur and Prehistoric Animal News Stories, Main Page|0 Comments

Different Types of Dinosaurs Evolved Different Cooling Systems

Giant dinosaurs, be they bird-hipped leviathans such as Ankylosaurus, huge meat-eating theropods such as Tyrannosaurus rex and Carnotaurus, or the biggest terrestrial animals known to science, sauropods such as Diplodocus, Camarasaurus and Brachiosaurus all faced the same problem when it came to keeping cool.  New research from the Heritage College of Osteopathic Medicine (part of Ohio University), suggests that different types of giant dinosaur solved the overheating problem in different ways.  In essence, in order to prevent the brains of these large-bodied tetrapods from overheating, they developed different cooling systems in different parts of their heads.

Thermoregulatory Function in the Skulls of Diplodocids

How Diplodocus may have kept cool.

To avoid overheating, the sauropod Diplodocus may have panted, moving air back and forth through its mouth and nose to help cool its blood.

Picture Credit: Michael Skrepnick and Witmerlab (Ohio University)

How to Avoid the Head Overheating?

Researchers writing in the journal “The Anatomical Record”, the publication of the American Association for Anatomy, studied the skulls of a variety of large dinosaurs and compared them to living reptiles and archosaurs – crocodiles and birds and they concluded that different genera of giant dinosaurs solved the problem of overheating in different ways, essentially evolving different cooling systems in different parts of the skull.

Lead author of the study, Ruger Porter (Assistant Professor of Anatomical Instruction, Ohio University) explained:

“The brain and sense organs like the eye are very sensitive to temperature.  Animals today often have elaborate thermoregulatory strategies to protect these tissues by shuttling hot and cool blood around various networks of blood vessels.  We wanted to see if dinosaurs were doing the same things.”

Dinosaurs evolved from much smaller ancestors and as these animals grew bigger, so their surface area to volume ratios changed.   Large bodies retain heat more effectively than small bodies, keeping warm may not have been too much of a problem for a thirty tonne sauropod, but losing heat, being able to keep cool, that would have been quite a challenge for such animals.

Co-author of the study, Professor Lawrence Witmer (Department of Biomedical Sciences, Ohio University) commented:

“Small dinosaurs could have just run into the shade to cool off, but for those giant dinosaurs, the potential for overheating was literally inescapable.  They must have had special mechanisms to control brain temperature, but what were they?”

As Dinosaurs Got Bigger so Thermoregulation Issues Got Bigger Too

Sauropodamorpha size comparison.

Sauropodamorpha size comparison Plateosaurus, Lufengosaurus and Ingentia prima compared.  As dinosaur body size increased, these animals had to evolve ways to help them to lose heat and to keep cool.

Picture Credit: Everything Dinosaur

An Explanation Based on Physics – Dinosaurs Kept Cool Using Evaporation

The researchers obtained carcases of birds and reptiles that had died from natural causes from various zoos and wildlife centres.  They then plotted the location of blood vessels using CT scans in those part of the animal’s body that were associated with evaporative cooling.  Areas such as the nostrils, the mouth and the eyes, areas where moisture is present would facilitate evaporative cooling of any blood that followed through these areas.  The scientists accurately measured bony canals and grooves that conveyed the blood vessels within a series of dinosaur skulls.

Porter added:

“The handy thing about blood vessels is that they basically write their presence into the bones.  The bony canals and grooves that we see in modern-day birds and reptiles are our link to the dinosaur fossils.  We can use this bony evidence to restore the patterns of blood flow in extinct dinosaurs and hopefully get a glimpse into their thermal physiology and how they dealt with heat.”

Ruger Porter and Lawrence Witmer with Various Casts of Dinosaur Skulls

Scientists examine how dinosaurs kept cool.

Researchers Porter (left) and Witmer (right) with some of the skull casts of dinosaurs assessed in the research.

Picture Credit: Witmer Lab (University of Ohio)

Sharon Swartz, a programme director at the National Science Foundation, which funded the research stated:

“The discovery that different dinosaurs cooled their brains in a variety of ways not only provides a window into the everyday life of dinosaurs, it also serves as an exemplar of how the physical constraints imposed by specific environmental conditions have shaped the evolution of this diverse and unique group.  Using a combination of technological innovation and biological expertise, these researchers were able to take a direct reading from the fossil record that provides new clues about how dinosaur skeletal form and function evolved.”

One Size Does Not Fit All

Expanding upon previous research, this new paper identifies that dinosaurs evolved subtly different solutions to the problem of heat stroke.  A key factor turned out to be body size.  Small dinosaurs such as pachycephalosaurs had a very balanced pattern of blood vessels with no single cooling region being dominant.  Such dinosaurs, most of which were around 2-3 metres in length could seek out shade to keep cool and therefore probably had fewer problems when it came to thermoregulation.  Huge dinosaurs such as the sauropods and the ankylosaurs increased blood flow to particular cooling regions of the head, they had an overabundance of blood vessels in parts of their skull that would have contributed to cooling.  This unbalanced vascular pattern allowed the thermal strategies of large dinosaurs to be more focused, emphasising one or more cooling regions.

Evaporation Helped to Keep Dinosaurs Cool

An overabundance of blood vessels in certain areas of the skull helped diplodocids keep cool.

How diplodocids kept cool.

Picture Credit: Witmer Lab (University of Ohio) with life reconstruction by Michael Skrepnick

Different Cooling Regions

Although sauropods and ankylosaurs (Euoplocephalus), all had unbalanced vascular patterns highlighting centres of cooling, they still differed.  Sauropods, for example, had greater emphasis on the nasal cavity and the mouth as cooling regions, whereas it was the complicated sinuses of ankylosaurs that helped them to lose heat.

Porter commented:

“It’s possible that sauropods were so large, often weighing dozens of tons, that they needed to recruit the mouth as a cooling region in times of heat stress.  Panting sauropods may have been a common sight!”

One interesting anomaly highlighted by this research is that many of the theropod dinosaurs such as Carnotaurus and Tyrannosaurus rex may have possessed balanced vascular patterns, similar to those identified in much smaller dinosaurs.

Professor Witmer outlined how theropods might have kept cool:

“This finding had us scratching our heads until we noticed the obvious difference—theropods like Majungasaurus and T. rex had a huge air sinus in their snouts.”

Earlier studies had shown that large theropods had an antorbital air sinus that was supplied with many blood vessels.  Air circulated through the antorbital air sinus like a bellows pump every time these animals breathed.  Such an actively ventilated, vascular sinus would provide a potential cooling region for these huge bipeds.

The scientists hope to continue this area of study including other Ornithischian dinosaur such as ceratopsids and hadrosaurs to see if these types of dinosaurs evolved different thermoregulatory strategies.

To read a related article on how armoured dinosaurs kept themselves cool: Convoluted Nasal Passages Helped Armoured Dinosaurs Cool their Brains

Everything Dinosaur acknowledges the assistance of a press release from Ohio University in the compilation of this article.

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