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

10 03, 2024

A New Lower Permian Amphibian is Scientifically Described

By | March 10th, 2024|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Researchers have scientifically described a new taxon of amphibian from the Lower Permian of Germany. The animal has been named Bromerpeton subcolossus. Researchers from the Museum für Naturkunde in Berlin (Germany) in collaboration with colleagues from the United States suggest that this small tetrapod probably spent much of its time underground.

Holotype of Bromerpeton subcolossus (specimen number MNG 16545).
A prepared block revealing the Bromerpeton subcolossus holotype (specimen number MNG 16545). Picture credit: Carola Radke.

Bromerpeton subcolossus

A block of undescribed fossils was carefully cleaned and prepared at the Carnegie Museum of Natural History in Pittsburgh (USA). When these fossils were examined in detail it was discovered that they represented a new taxon. Bromerpeton has been classified as a member of the Recumbirostra clade.

The fossil material comes from the famous “Bromacker” location in Thuringia, central Germany. The siltstones and sandstones preserve both trace and body fossils of early tetrapods. More than a dozen new species have been named and described. This fossil site was formed by the deposition of sediments in a high plateau environment. Most Permian vertebrate fossil sites represent lowland ecosystems close to bodies of water.

Computed tomography (CT) scans revealed an exceptionally well-preserved right forelimb with five fingers. This is an unusual characteristic within the Recumbirostra clade. Most have only three or four digits on the manus.

Lead author of the paper, Dr Mark MacDougall (Museum für Naturkunde – Berlin), explained that Bromerpeton subcolossus was less than fifteen centimetres in length. Its skull was just two centimetres long.

Fossorial (Burrowing) Adaptations

Despite being diminutive, Bromerpeton possessed sturdy limbs with a broad manus (hand) and pointed claws. The researchers postulate that Bromerpeton subcolossus dug burrows and spent much of its time underground. The fossil material is estimated to be around 290 million years old (Lower Permian).

Dr Mark MacDougall remarked:

“Bromerpeton may be small, but it provides a lot of new information about the evolution and ecology of early tetrapods and in particular the Recumbirostra, a group that has received a lot of attention in recent years. Our discovery also contributes to understanding the diversity of the Lower Permian Bromacker ecosystem.”

Everything Dinosaur acknowledges the assistance of a media release from the Museum für Naturkunde (Berlin) in the compilation of this article.

The scientific paper: “A new recumbirostran ‘microsaur’ from the lower Permian Bromacker locality, Thuringia, Germany, and its fossorial adaptations” by Mark MacDougall, Andréas Jannel, Amy Henrici, David S Berman, Stuart S. Sumida, Thomas Martens, Nadia Fröbisch and Jörg Fröbisch published in Scientific Reports.

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9 03, 2024

New Research Identifies Earth’s Oldest Forest in Devon Cliffs

By | March 9th, 2024|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Evidence of a Devonian fossil forest has been found in the high sandstone cliffs located near Minehead in Devon. Researchers from the University of Cambridge and the University of Cardiff have discovered the oldest fossilised trees ever found in the UK. The fossil remains of the trees, known as Calamophyton represent the oldest known fossil forest on Earth.

Fossilised tree stumps near the town of Gilboa (New York, USA) and a quarry at nearby Cairo, New York are thought to be 380 and 385 million years old respectively. The Gilboa site is dominated by remains of Wattieza trees. These trees are related to the Calamophyton trees identified at the Devon site. They are both members of the Pseudosporochnales Order and are distantly related to modern ferns.

Devonian strata in the cliffs near Minehead.
The cliffs close to the Butlin’s holiday camp near Minehead (Devon) where the fossils were found. Picture credit: Neil Davies (University of Cambridge).

Devonian Fossil Forest

The Devonian fossil forest is thought to be around four million years older than the tree fossils discovered in New York. The forest is approximately 390 million years old (Eifelian faunal stage of the Middle Devonian).

Devon fossil forest details of a fallen tree trunk.
Detail of a fallen tree truck. Picture credit: Chris Berry (University of Cardiff).

The fossils were found near the town of Minehead. The site is located on the south bank of the Bristol Channel, near a Butlin’s holiday camp. The fossilised trees, known as Calamophyton, at first glance resemble palm trees, but they are not related to modern angiosperms. Rather than solid wood, their trunks were thin and hollow in the centre. They also lacked leaves, and their branches were covered in hundreds of twig-like structures.

Devon fossil forest life reconstruction (Calamophyton).
Devon fossil forest life reconstruction showing Calamophyton. Picture credit: Peter Giesen/Chris Berry.

Evidence of Arthropods Found

The trees were much shorter than extant trees. The largest specimens were between two and four metres high. As the trees grew, they shed their branches. The floor of the forest was covered in a dense mat of decaying vegetation. This was home to an array of invertebrates and arthropod tracks have been discovered at this site.

Arthropod tracks recorded at the Devon fossil forest site.
Arthropod tracks recorded at the Devon fossil forest site. Picture credit: Neil Davies (University of Cambridge).

A Devonian Ecosystem

It had been thought that these sandstone cliffs were largely devoid of fossils. This remarkable discovery demonstrates how early trees helped to stabilise riverbanks and coastlines hundreds of millions of years ago. It was during the Devonian that the first extensive terrestrial forests formed.

The Devonian lasted between 419 million and 359 million years ago. During this geological period the first complex terrestrial ecosystems evolved. By the end of the Devonian, the first seed-bearing plants (pteridosperms) appeared and the earliest land animals, mostly arthropods, were well-established.

Small tree stumps.
A photograph showing an area of small tree stumps. Picture credit: Neil Davies (University of Cambridge).

Fundamentally Changing Life on Earth

Commenting on the significance of the fossil forest discovery, one of the paper’s co-authors, Professor Neil Davies (Cambridge University), stated:

“The Devonian period fundamentally changed life on Earth. It also changed how water and land interacted with each other, since trees and other plants helped stabilise sediment through their root systems, but little is known about the very earliest forests.”

The Devonian fossil forest identified by the researchers was found in the Hangman Sandstone Formation, along the north Devon and west Somerset coasts. During the Devonian period, this region was not attached to the rest of England, but instead lay further south, connected to parts of Germany and Belgium, where similar Devonian fossils have been found.

Ripple marks on the forest floor.
Ripple marks on the forest floor. Picture credit: Neil Davies (University of Cambridge).

Studying the Ecology of the Earliest Forests on Earth

Co-author Dr Christopher Berry (Cardiff University) commented:

“When I first saw pictures of the tree trunks I immediately knew what they were, based on 30 years of studying this type of tree worldwide. It was amazing to see them so near to home. But the most revealing insight comes from seeing, for the first time, these trees in the positions where they grew. It is our first opportunity to look directly at the ecology of this earliest type of forest, to interpret the environment in which Calamophyton trees were growing, and to evaluate their impact on the sedimentary system.”

During the Devonian, this location was a semi-arid plain, criss-crossed by small river channels spilling out from mountains to the northwest. The fieldwork was undertaken along the highest sea-cliffs in England, some of which are only accessible by boat. The sandstone formation is in fact rich with plant fossil material. The researchers identified fossilised plants and plant debris, fossilised tree logs, traces of roots and sedimentary structures, preserved within the sandstone.

Tree stump in cross-section
Cross section of tree stump. Picture credit: Neil Davies (University of Cambridge).

A Weird Forest

Professor Davies explained:

“This was a pretty weird forest – not like any forest you would see today. There wasn’t any undergrowth to speak of and grass hadn’t yet appeared, but there were lots of twigs dropped by these densely-packed trees, which had a big effect on the landscape.”

Small Devonian plant twigs.
Small plant twigs. Picture credit: Chris Berry (University of Cardiff).

This was the first time in the history of our planet that large plants could grow together on land. The sheer abundance of debris shed by the Calamophyton trees built up within layers of sediment. The sediment affected the way that the rivers flowed across the landscape, the first time that the course of rivers could be affected in this way.

Professor Davies added:

“The evidence contained in these fossils preserves a key stage in Earth’s development, when rivers started to operate in a fundamentally different way than they had before, becoming the great erosive force they are today. People sometimes think that British rocks have been looked at enough, but this shows that revisiting them can yield important new discoveries.”

Everything Dinosaur acknowledges the assistance of a media release from the University of Cambridge in the compilation of this article.

The scientific paper: “Earth’s earliest forest: fossilized trees and vegetation-induced sedimentary structures from the Middle Devonian (Eifelian) Hangman Sandstone Formation, Somerset and Devon, SW England” by Neil S. Davies, William J. McMahon and Christopher M. Berry published in Journal of the Geological Society.

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5 03, 2024

Khinjaria acuta A Bizarre New Mosasaur from Morocco

By | March 5th, 2024|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

A new mosasaur taxon from the Late Cretaceous of Morocco has been scientifically described. Khinjaria acuta was as long as an Orca (Orcinus orca). It had a robust skull, strong jaws and dagger-like teeth. The researchers contrast today’s marine ecosystems with few apex predators, with the Late Cretaceous marine environment. Writing in the journal “Cretaceous Research” the researchers portray an ancient marine ecosystem teeming with predators.

Khinjaria acuta life reconstruction.
A Khinjaria acuta life reconstruction. Picture credit: Andrey Atuchin.

Khinjaria acuta

The study is based on a skull and parts of the postcranial skeleton collected from a phosphate mine southeast of Casablanca (Morocco). Researchers from the University of Bath, the Marrakech Museum of Natural History, the Museum National d’ Histoire Naturelle (NMNH) in Paris (France), Southern Methodist University in Texas (USA), and the University of the Basque Country (Bilbao) were involved.

Measuring around eight metres in length, Khinjaria used its long, dagger-like teeth to seize prey. It was part of an extraordinarily diverse fauna of predators that inhabited the Atlantic Ocean off the coast of Morocco during the Maastrichtian faunal stage of the Late Cretaceous.

Khinjaria acuta skull (top) with explanatory line drawing (bottom).
A photograph of the skull material (top) with a line drawing of the skull fossil (bottom). Picture credit: University of Bath.

The Sheer Diversity of Top Predators in the Marine Ecosystem

One of the authors of the scientific paper, Dr Nick Longrich (University of Bath), stated:

“What’s remarkable here is the sheer diversity of top predators. We have multiple species growing larger than a great white shark, and they’re top predators, but they all have different teeth, suggesting they’re hunting in different ways.”

The reconstructed skull of Khinjaria acuta shown in lateral view.
The reconstructed skull of Khinjaria acuta shown in lateral view. Picture credit: Nick Longrich.

Dr Longrich added:

“Some mosasaurs had teeth to pierce prey, others to cut, tear, or crush. Now we have Khinjaria, with a short face full of huge, dagger-shaped teeth. This is one of the most diverse marine faunas seen anywhere, at any time in history, and it existed just before the marine reptiles and the dinosaurs went extinct.”

A Diversity of Moroccan Marine Reptiles

Fossil discoveries have highlighted the astonishing diversity of large marine reptiles in the environment. Their different dentition suggests that many were not directly competing, that niche partitioning was occurring. For example, the researchers conducted a phylogenetic analysis and placed Khinjaria in a mosasaur clade which they named the Selmasaurini. Also placed in this clade was the Moroccan plioplatecarpine mosasaur Gavialimimus almaghribensis. This mosasaur was a specialised fish hunter.

To read Everything Dinosaur’s article about Gavialimimus almaghribensis: A New Species of Mosasaur from Morocco.

Mosasaurs, plesiosaurs and giant sea turtles disappeared, along with entire families of fish at the end of the Cretaceous. This led to the evolution of modern marine ecosystems with whales and seals as apex predators along with teleost fish such as swordfish and tuna.

Dr Longrich commented:

“There seems to have been a huge change in the ecosystem structure in the past 66 million years. This incredible diversity of top predators in the Late Cretaceous is unusual, and we don’t see that in modern marine communities.”

Estimated size of Khinjaria.
A Khinjaria silhouette next to a diver to show the approximate scale. Picture credit: Nick Longrich.

An Ecosystem Different from a Modern Marine Ecosystem

Modern marine food chains have just a few large apex predators, animals like orcas, white sharks, and leopard seals. The Late Cretaceous had many more types of marine predators.

Dr Longrich continued:

“Modern ecosystems have predators like baleen whales and dolphins that eat small prey, and not many things eating large prey. The Cretaceous has a huge number of marine reptile species that take large prey. Whether there’s something about marine reptiles that caused the ecosystem to be different, or the prey, or perhaps the environment, we don’t know. But this was an incredibly dangerous time to be a fish, a sea turtle, or even a marine reptile.”

Professor Nathalie Bardet, (Natural History Museum of Paris), explained:

“The Phosphates of Morocco deposit in a shallow and warm epicontinental sea, under a system of upwellings; these zones are caused by currents of deep, cold, nutrient-rich waters rising towards the surface, providing food for large numbers of sea creatures and, as a result, supporting a lot of predators. This is probably one of the explanations for this extraordinary paleobiodiversity observed in Morocco at the end of the Cretaceous.”.

The phosphate mines of Morocco have provided a wealth of marine fossil material. The specimens collected include the “saw-toothed” mosasaur Xenodens, Stelladens which had teeth with additional cutting edges and Thalassotitan whose teeth were conical in shape and massive.

Everything Dinosaur acknowledges the assistance of a media release from the University of Bath in the compilation of this article.

The scientific paper: “A bizarre new plioplatecarpine mosasaurid from the Maastrichtian of Morocco” by Nicholas R. Longrich, Michael J. Polcyn, Nour-Eddine Jalil, Xabier Pereda-Suberbiola and Nathalie Bardet published in Cretaceous Research.

Take a look at the Everything Dinosaur website: Everything Dinosaur.

23 02, 2024

Dinocephalosaurus and the Year of the Dragon

By | February 23rd, 2024|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|1 Comment

A team of scientists have described new specimens of Dinocephalosaurus orientalis a bizarre, Triassic marine reptile. First scientifically described in 2003 (Li Chun), this new study has permitted scientists to construct the enormous neck of this animal in detail.

Measuring up to five metres in length, Dinocephalosaurus orientalis had an extremely long and flexible neck. The neck contains a total of thirty-two vertebrae. Tanystropheus in contrast, had thirteen cervical vertebrae. In some specimens the neck is 1.7 metres in length. It is much longer than the animal’s torso. The researchers compare D. orientalis to the Tanystropheus taxon. Tanystropheus is known from the Middle Triassic of Europe and China. Whilst Tanystropheus and Dinocephalosaurus had similar body shapes, these reptiles were not closely related. The long necks seen in these two taxa are an example of convergent evolution.

Dinocephalosaurus orientalis life reconstruction.
Dinocephalosaurus orientalis swimming amongst some prehistoric fish known as Saurichthys. Picture credit: Marlene Donelly.

Dinocephalosaurus orientalis A Remarkable Marine Reptile

The scientific paper describing the animal is published in full in the academic journal Earth and Environmental Science: Transactions of the Royal Society of Edinburgh – forming the entirety of the latest volume.

Fellow of the Royal Society of Edinburgh and Editor-in-Chief of the RSE’s academic journal Transactions, Professor Robert Ellam FRSE commented:

“This remarkable marine reptile is another example of the stunning fossils that continue to be discovered in China”.

Comparisons with Tanystropheus

Both reptiles were of similar size and have several features of the skull in common, including a fish-trap type of dentition. However, Dinocephalosaurus is unique in possessing several more vertebrae both in the neck and in the torso, giving the animal a much more snake-like appearance. The neck of Dinocephalosaurus was more flexible than the neck of Tanystropheus. The fossils analysed in the newly published paper come from the Guizhou Province of China.

Dinocephalosaurus orientalis fossil specimen.
A nearly complete and articulated specimen of Dinocephalosaurus orientalis. Picture credit: The Royal Society of Edinburgh.

Dr Nick Fraser FRSE, Keeper of Natural Sciences at National Museums Scotland stated:

“This discovery allows us to see this remarkable long-necked animal in full for the very first time. It is yet one more example of the weird and wonderful world of the Triassic that continues to baffle palaeontologists. We are certain that it will capture imaginations across the globe due to its striking appearance, reminiscent of the long and snake-like, mythical Chinese Dragon.”

Appropriate for the “Year of the Dragon”

As we have now entered the Chinese “Year of the Dragon”, a new scientific paper on a Chinese reptile that superficially resembled a mythical dragon is highly appropriate. The fossils were studied over a period of ten years by researchers from Scotland, China, America and Germany.

Professor Li Chun from the Institute of Vertebrate Palaeontology and Palaeoanthropology in China, the scientist who originally described Dinocephalosaurus orientalis said:

“This has been an international effort. Working together with colleagues from the United States of America, the United Kingdom and Europe, we used newly discovered specimens housed at the Chinese Academy of Sciences to build on our existing knowledge of this animal. Among all of the extraordinary finds we have made in the Triassic of Guizhou Province, Dinocephalosaurus probably stands out as the most remarkable.”

Scientists propose that Dinocephalosaurus was superbly adapted to its marine environment. Given the length of its neck, moving on land would have been difficult. A remarkable fossil described in 2017 revealed that Dinocephalosaurus was viviparous (live birth). This remains the only record of viviparity associated with the Archosauromorpha.

To read Everything Dinosaur’s blog post about this discovery: First Evidence of Live Birth in Ancient Dinosaur Relative.

Dinocephalosaurus orientalis – Significant Fossil Discoveries

Dr Stephan Spiekman, a postdoctoral researcher based at the Stuttgart State Museum of Natural History, commented:

“As an early-career researcher, it has been an incredible experience to contribute to these significant findings. We hope that our future research will help us understand more about the evolution of this group of animals, and particularly how the elongate neck functioned.”

The paper describing the animal is published in full in the academic journal Earth and Environmental Science: Transactions of the Royal Society of Edinburgh – forming the entirety of the latest volume. The journal was first published in 1788.

Everything Dinosaur acknowledges the assistance of media releases from the Royal Society of Edinburgh and National Museums Scotland in the compilation of this article.

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20 02, 2024

New Lambeosaurine Dinosaur Described from Morocco

By | February 20th, 2024|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

A new, pony-sized Moroccan lambeosaurine dinosaur has been named and described. The new dinosaur has been named Minqaria bata. It closely resembles the only previously known African duckbill, Ajnabia odysseus. However, the shape of the jaws and teeth are unique, demonstrating it was a distinct species. Minqaria probably occupied a different ecological niche.

Minqaria life reconstruction.
A trio of lambeosaurines (Minqaria bata) wander past the corpse of a large mosasaur. Picture credit: Raul Martin.

Minqaria bata – (Arabic for “Beak” and “Duck” Respectively)

The fossils consisting of a right maxilla with teeth, a partial left dentary and the braincase come from marine phosphate deposits located at Sidi Chennane in the Oulad Abdoun Basin. The size of the fossils, the associated matrix and the lack of duplication of elements suggests that these fossils came from a single, mature dinosaur. They represent a dwarf duck-billed dinosaur, a Late Cretaceous lambeosaurine that was smaller than Ajnabia odysseus, the first hadrosaurid known from Africa (Longrich et al, 2020). M. bata is estimated to have been around 3.5 metres in length and weighed approximately 250 kilograms.

To read Everything Dinosaur’s 2020 blog post about Ajnabia odysseus: The First Hadrosaurid Dinosaur from Africa.

The genus name is derived from the Arabic “minqar” which means beak and the species name is from the Arabic “bata” for duck.

Minqaria skull showing placement of fossil bones.
Approximate life position of skull fossils associated with the newly described lambeosaurine taxon Minqaria bata. Picture credit: Nick Longrich.

The Diversity of North African Lambeosaurines

A humerus and femur also described in the scientific paper appear to represent lambeosaurines too. However, their size indicates that larger lambeosaurines, animals longer than six metres in length were also present in the ecosystem.

The discovery of Ajnabia in 2020 was surprising. During the Late Cretaceous, hundreds of miles of water separated North Africa from Eurasia. The new lambeosaurine fossils not only confirm the existence of lambeosaurines in North Africa, but shows they were diverse, with at least four taxa present.

The dinosaur fauna of Morocco during the Late Cretaceous.
The dinosaur fauna of Morocco during the Late Cretaceous. Picture credit: Nick Longrich.

How Did Duck-billed Dinosaurs Get to North Africa?

This new study published in the journal “Scientific Reports” reveals that not only did duckbills manage to cross the Tethys Sea, but they became highly diverse once they colonised Africa. The duck-billed dinosaurs are thought to have evolved in North America. Africa during the Late Cretaceous was an isolated continent, surrounded on all sides by water. So, how did duckbill dinosaurs, a group that evolved in North America, end up in Morocco?

Anatomical traits of Minqaria are similar to European hadrosaurs. The researchers postulate that duckbills either swam or floated across several hundred kilometres of open water to colonise Africa.

Dr Nick Longrich (University of Bath), who led the study commented:

“These were probably loud, vocal animals. Modern birds vocalise to find mates, or to declare territories. But they’re especially vocal in flocks – a flock of flamingos or a nesting colony of pelicans is extremely noisy, constantly communicating. So, it’s likely that like birds, these duckbills were social animals.”

Part of the dentary (lower jaw) of Minqaria bata.
Part of the dentary (lower jaw) of Minqaria bata. Picture credit: University of Bath.

Social Dinosaurs

The brain is also large by dinosaur standards, a feature associated with social animals like crows and primates.

Dr Longrich explained:

“There were probably very loud, noisy herds – or flocks if you prefer – of these little duckbills wandering the coasts of Morocco 66 million years ago.”

Minqaria bata braincase.
The braincase of the newly described Moroccan lambeosaurine Minqaria bata. Picture credit: University of Bath.

Commenting on the presence of lambeosaurine dinosaurs on the isolated continent of Africa, Dr Longrich added:

“Not only did duckbills manage to reach Africa at the end of the Cretaceous, but once they did, they quickly evolved to take advantage of open niches and became diverse.”

Analogies can be found in the modern world. Animals can sometimes make unexpected and unusual journeys across large bodies of water. During the Ice Age, elephants, deer and hippos were able to cross the Mediterranean Sea to reach the island of Crete. Iguanas swept offshore by a hurricane can be transported hundreds of miles to other Caribbean islands as they cling to dislodged vegetation.

Dr Longrich stated:

“It’s extremely improbable that dinosaurs could cross water to get to Africa, but improbable isn’t the same as impossible. And given enough time, improbable things become probable. Buy a lottery ticket every day, and if you wait long enough, you’ll win. These ocean crossings might be once-in-a-million-year events but the Cretaceous lasted nearly 100 million years. A lot of strange things will happen in that time – including dinosaurs crossing seas.”

Remarkable to Discover Fossils of Hadrosaurs Like Minqaria bata in Africa

Co-author Dr Nour-Eddine Jalil (Natural History Museum of Paris and the Université Cadi Ayyad in Morocco) commented:

“Minqaria and its relatives are players that a few years ago we would never have supposed to be on the African continent at that time.”

The doctor added:

“The phosphates of Morocco offers new images on past biodiversity in a key period of the history of life, the last moments of the dinosaur age followed by the diversification of mammals, announcing a new era. Despite their marine origin, these phosphates of Morocco also contain remains of vertebrates that lived on land. They constitute one of the only windows on the terrestrial ecosystems in Africa. The dinosaur remains suggest a great diversity, all the three major groups of dinosaurs are represented, the abelisaurid carnivores and the sauropod and ornithischian herbivores.”

Everything Dinosaur acknowledges the assistance of a media release from the University of Bath in the compilation of this article.

The scientific paper: “A new small duckbilled dinosaur (Hadrosauridae: Lambeosaurinae) from Morocco and dinosaur diversity in the late Maastrichtian of North Africa” by Nicholas R. Longrich, Xabier Pereda-Suberbiola, Nathalie Bardet and Nour-Eddine Jalil published in Scientific Reports.

The Everything Dinosaur website: Everything Dinosaur.

19 02, 2024

New Study Demonstrates Tridentinosaurus Fossil is a Fake

By | February 19th, 2024|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

A fossil once thought to represent an Early Permian reptile with soft tissue preservation has been proven to be a fake. The fossilised remains of a lizard-like reptile named Tridentinosaurus antiquus were found in the 1930s. It was thought to be an extremely rare fossil with carbonised skin impressions surrounding the articulated fossil bones. However, a detailed analysis of the specimen has revealed that these “soft tissues” were painted on.

Images of the Tridentinosaurus antiquus fossil specimen.
Tridentinosaurus antiquus fossil specimen (A) showing sampling locations with (B) surface map of the fossil. The specimen photographed under UV light (C). Analysis revealed that the purported fossilised soft tissues of T. antiquus were forged. Picture credit: Rossi et al.

Tridentinosaurus antiquus Specimen is a Forgery

Discovered in the Italian Alps near the “Stramaiolo” (Redebus) locality in the Pinè Valley, the fossil was thought to represent one of the oldest, nearly complete and articulated reptiles known to science. Writing in the journal “Palaeontology”, the research team used a variety of techniques to analyse the surface structure of the twenty-centimetre-long fossil.

The results demonstrated that the purported fossilised soft tissues of Tridentinosaurus antiquus are not original. The fossil is a forgery. The paint applied within the prepared area around the poorly preserved bones and osteoderms, produced the shape of a slender lizard-like animal making the specimen look authentic.

Carbonised plant remains are known from the same locality. The forged body outline and soft tissues misled scientists who thought that the soft tissue had been carbonised just like plant fossils from this region. Under ultraviolet light the plant fossils did not fluoresce, however, the reptile fossil outline became fluorescent. Normally, carbonised fossil material does not fluoresce when exposed to UV light. However, artificial pigments, vanishes and glues are likely to become fluorescent.

The Validity of the Taxon is Doubted

Tridentinosaurus antiquus represents one of the oldest fossil reptiles known to science. The taphonomy and the appearance of this fossil had puzzled palaeontologists for decades. It was thought to represent a primitive diapsid reptile, a basal member of the Archosauromorpha that gave rise to the dinosaurs, crocodiles and birds.

The researchers were able to confirm that many of the features of this specimen had been forged. This discovery raises questions about the validity of this enigmatic taxon.

Despite the manipulation of the specimen, it may still have scientific value. The poorly preserved long bones of the hindlimbs seem to be genuine and resemble the quality of preservation of exposed bones of Late Triassic pterosauromorphs such as Scleromochlus. Perhaps, this fossil is an example of the lineage of basal archosaurs that gave rise to the flying reptiles (Pterosauria).

Close-up views of the Tridentinosaurus antiquus fossil specimen.
Close-up view of the shoulder area (D) and an enlargement of the pelvic girdle (E). Although much of the fossil has been altered some bones seem to be genuine and resemble the quality of preservation of exposed bones of Late Triassic pterosauromorphs such as Scleromochlus. Scale bar in (D) equals 5 mm. The scale bar (E) equals 3 mm. Picture credit: Rossi et al.

Why Fake a Fossil?

Fossils are sometimes manipulated to make them more valuable to collectors. If the fossil can be seen to be more complete or rare it can greatly enhance their monetary value.

Everything Dinosaur acknowledges the assistance of a media release from the Museum of Nature South Tyrol (Naturmuseum Südtirol) in the compilation of this article.

The scientific paper: “Forged soft tissues revealed in the oldest fossil reptile from the early Permian of the Alps” by Valentina Rossi, Massimo Bernardi, Mariagabriella Fornasiero, Fabrizio Nestola, Richard Unitt, Stefano Castelli, Evelyn Kustatscher published in Palaeontology.

Visit the Everything Dinosaur website (there are no fakes here): Everything Dinosaur.

7 02, 2024

New Research into Dinosaur Locomotion

By | February 7th, 2024|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

Newly published research examining dinosaur locomotion and comparing it with other archosaurs suggests that the way in which dinosaurs moved could have given them a competitive advantage.

The research was undertaken by a team from the University of Bristol. It has been published today in Royal Society Open Science. The team’s findings indicate that the earliest dinosaurs were simply faster and more dynamic than their competitors. Perhaps the greater locomotor plasticity of dinosaurs gave them a distinctive advantage over other terrestrial animals. This may help to explain why the dinosaur/pterosaur/bird branch of the archosaurs, the Avemetatarsalia eventually outcompeted the archosaur crocodilian lineage (Pseudosuchia).

Studying Dinosaur Locomotion

The researchers compared the limb proportions of an extensive range of archosaurs that lived during the Triassic. In total, the limb proportions of 208 taxa were studied. The research team identified which of these tetrapods was quadrupedal (four-footed) or bipedal (two-footed). The cursoriality index of each animal was also examined. The cursoriality index is essentially a measure of running ability.

The results demonstrated that the earliest dinosaurs and their close relatives were bipedal and cursorial – they had limbs adapted for running. These animals, members of the Avemetatarsalia subgroup of the archosaurs had a much wider range of running styles compared to the other archosaur lineage, the Pseudosuchia.

Dinosaur locomotion study.
Evolutionary tree showing how dinosaur limb adaptation expanded through the Triassic period until it was greater overall than the spread of locomotion types in their competitors, including pseudosuchians, other avemetatarsalians, and other archosaurs. These changes also included many early dinosaurs with strong adaptations to cursoriality (running). Mass extinctions are marked along the time scale: PTME, Permian-Triassic mass extinction; CPE, Carnian pluvial episode; ETME, end-Triassic mass extinction). Picture credit: Amy Shipley.

A Higher Range of Locomotory Modes by the Avemetatarsalia

The Pseudosuchia include the ancestors of extant crocodilians. Some were small, bipedal insectivores, but most were medium-to-large-sized carnivores and herbivores, and they were very successful throughout the Triassic. The research team calculated that the Dinosauria and other members of the Avemetatarsalia, maintained a higher range of locomotory modes throughout this period.

Lead author of the study Amy Shipley commented:

“When the crunch came, 233 million years ago, dinosaurs won out”.

The MSc Palaeobiology student at the University of Bristol added:

“At that time, climates went from wet to dry, and there was severe pressure for food. Somehow the dinosaurs, which had been around in low numbers already for twenty million years, took off and the pseudosuchians did not. It’s likely the early dinosaurs were good at water conservation, as many modern reptiles and birds are today. But our evidence shows that their greater adaptability in walking and running played a key part.”

Dinosaur locomotion and evolution of the femur.
Evolution of the thigh bone (femur) through the Triassic, starting with a very limited array of shapes, and ending with a broad array of shapes for the dinosaur femur (high disparity), indicating a wide range of locomotion modes. Picture credit: Amy Shipley.

The End Triassic Mass Extinction Event (ETME)

Co-author of the paper, Professor Mike Benton explained that at the end of the Triassic there was a mass extinction event. Most of the pseudosuchians died out, except for the ancestors of today’s crocodilians. The surviving dinosaurs expanded their range of locomotion again, taking over many of the empty niches in food webs.

Co-author Dr Armin Elsler added:

“When we looked at evolutionary rates, we found that in fact dinosaurs were not evolving particularly fast. This was a surprise because we expected to see fast evolution in avemetatarsalians and slower evolution in pseudosuchians. What this means is that the locomotion style of dinosaurs was advantageous to them, but it was not an engine of intense evolutionary selection. In other words, when crises happened, they were well placed to take advantage of opportunities after the crisis.”

Dinosaur locomotion a key to their evolutionary sucess.
An illustration of the early dinosaur Eoraptor lunensis from the Upper Triassic Ischigualasto Formation of Argentina. Picture credit: Nobu Tamura.

Could Dinosaur Locomotion be Key to Their Evolutionary Success?

Fellow collaborator Dr Tom Stubbs stated that the word “dinosaur” conjures up in the public’s imagination a slow-moving, large and lumbering animal. The first dinosaurs, animals such as Eoraptor lunensis were very different. The first members of the Dinosauria were small and agile.

Dr Stubbs said:

“The first dinosaurs were only a metre long, up high on their legs, and bipedal. Their leg posture meant they could move fast and catch their prey while escaping larger predators.”

Co-author Dr Suresh Singh concluded:

“And of course, their diversity of posture and focus on fast running meant that dinosaurs could diversify when they had the chance. After the end-Triassic mass extinction, we get truly huge dinosaurs, over ten metres long, some with armour, many quadrupedal, but many still bipedal like their ancestors. The diversity of their posture and gait meant they were immensely adaptable, and this ensured strong success on Earth for so long.”

Everything Dinosaur acknowledges the assistance of a media release from Bristol University in the compilation of this article.

The scientific paper: “Locomotion and the early Mesozoic success of Archosauromorpha” by Amy E. Shipley, Armin Elsler, Suresh A. Singh, Thomas L. Stubbs and Michael J. Benton published in Royal Society Open Science.

The Everything Dinosaur website: Everything Dinosaur.

6 02, 2024

New Species of Jurassic Pterosaur from the Isle of Skye

By | February 6th, 2024|Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

A new species of Jurassic pterosaur has been described based on fossils found on the Isle of Skye. The new flying reptile has been named Ceoptera evansae (Ki-yo-op-ter-rah evans-say). It lived around 168-166 million years ago (Bathonian faunal stage of the Middle Jurassic). It has been classified as part of the controversial Darwinoptera clade. The discovery of Ceoptera demonstrates that this clade was considerably more diverse than previously thought. The Darwinoptera are now thought to have persisted for more than twenty-five million years and probably had a worldwide distribution.

Ceoptera life reconstruction
The Isle of Skye around 168 million years ago. A flock of Ceoptera take to the skies as turtles look on and a group of sauropods wander towards the treeline. A large pterosaur is seen overhead, we suspect that this is a solitary Dearc sgiathanach. Picture credit: NHM and Mark Witton.

The artist has depicted a single, slender-winged pterosaur soaring high above the Ceoptera flock. We suspect that this is a representation of the recently described rhamphorhynchid Dearc sgiathanach.

To read an article about D. sgiathanach: Fantastic Pterosaur from the Isle of Skye.

The Kilmaluag Formation

The fossil remains were found partially exposed on a large boulder situated a few metres from the cliffs on the north side of Glen Scaladal at Cladach a’Ghlinne, a small beach that forms part of the coastline of Loch Scavaig, on the Strathaird Peninsula, Isle of Skye. The fossil bearing rocks are associated with the Kilmaluag Formation. The density and hardness of the matrix, coupled with the fragile nature of the fossil bones made the specimen unsuitable for mechanical preparation.

A complex process of acid bath immersion was undertaken to weaken the matrix and to expose the bones. The acid immersion, stabilising via rinsing and oven drying was repeated twenty-nine times in order to get the bones suitably prepared for analysis and CT scanning.

Ceoptera evansae fossils.
The fossilised remains of Ceoptera evansae. The slab (top left) contains the shoulder region, parts of the wing and vertebrae. Picture credit: Trustees of the Natural History Museum London.

Ceoptera evansae

The discovery of Ceoptera underpins a new and more complex model for the early evolution of pterosaurs. Flying reptile fossils from the Middle Jurassic are extremely rare. Those that have been found are relatively incomplete and fragmentary. Whilst no cranial material is associated with Ceoptera evansae, this discovery demonstrates that the major Jurassic pterosaur clades were present before the end of the Early Jurassic.

The fossils also provide important new information concerning the geographic and stratigraphic range of the controversial clade Darwinoptera. It had been thought that this species-poor group were largely restricted to the Upper Jurassic of eastern Asia. With the discovery of Ceoptera it suggests that these pterosaurs were both temporally and geographically widespread.

Many of the bones remain completely embedded in rock and can only be studied using CT-scanning. This pterosaur is one of the first flying reptiles to be digitally assessed using scans and computer modelling.

Senior author of the paper, Professor Paul Barrett (London Natural History Museum), stated:

“Ceoptera helps to narrow down the timing of several major events in the evolution of flying reptiles. Its appearance in the Middle Jurassic of the UK was a complete surprise, as most of its close relatives are from China. It shows that the advanced group of flying reptiles to which it belongs appeared earlier than we thought and quickly gained an almost worldwide distribution.”

3D model of Ceoptera evansae fossil material.
A three-dimensional model showing the layout and configuration of the fossil material. Picture credit: Liz Martin-Silverstone.

Ceoptera evansae – What’s in a Name?

The generic name is derived from the Scottish Gaelic word cheò or ceò (pronounced ‘ki-yo’), meaning mist. This is a reference to the common Gaelic name for the Isle of Skye Eilean a’ Cheò, or Isle of Mist), and the Latin ptera, meaning wing (feminine).

The species name honours Professor Susan E. Evans. It was Professor Evans who first became aware of the Glen Scaladal site’s potential for vertebrate fossils.

Lead author Dr Liz Martin-Silverstone, a palaeobiologist at the University of Bristol explained:

“The time period that Ceoptera is from is one of the most important periods of pterosaur evolution, and is also one in which we have some of the fewest specimens, indicating its significance. To find that there were more bones embedded within the rock, some of which were integral in identifying what kind of pterosaur Ceoptera is, made this an even better find than initially thought. It brings us one step closer to understanding where and when the more advanced pterosaurs evolved.”

Everything Dinosaur acknowledges the assistance of the press team at the University of Bristol and a media release from the London Natural History Museum in the compilation of this article.

The scientific paper: “A new pterosaur from the Middle Jurassic of Skye, Scotland and the early diversification of flying reptiles” by Elizabeth Martin-Silverstone, David M. Unwin, Andrew R. Cuff, Emily E. Brown, Lu Allington-Jones and Paul M. Barrett published in the Journal of Vertebrate Paleontology.

The Everything Dinosaur website: Everything Dinosaur.

5 02, 2024

University Student Discovers New Dinosaur Species

By | February 5th, 2024|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

To discover a new dinosaur species might mark the high point of a long career in palaeontology for some scientists. However, for one Oklahoma State University (OSU) student they can already put a tick in the “named a new dinosaur box” on their curriculum vitae. Kyle Atkins-Weltman (PhD student in the School of Biomedical Sciences), was studying a selection of foot and leg bone fossils of what was thought to be a juvenile Anzu wyliei. Remarkably, analysis of the fossils indicated that these bones came from a mature animal and as such they represented a new dinosaur species. Based on these findings, Kyle was able to erect a new Hell Creek theropod – Eoneophron infernalis.

Eoneophron infernalis limb bones.
Limb bones of the newly described Hell Creek Formation caenagnathid Eoneophron infernalis. Picture credit: Kyle Atkins-Weldman.

The picture (above) shows limb bones from the newly described caenagnathid. Metatarsals (left) with the right tibia (centre) and a femur (right).

Pharaoh’s Dawn Chicken from Hell

Bone histology revealed the fossils to represent a dinosaur at least six years of age when it died. These were not the bones from a juvenile A. wyliei, but from a smaller but closely related theropod species. The student named the new dinosaur Eoneophron infernalis. It translates as “Pharaoh’s dawn chicken from Hell”. Team members at UK-based Everything Dinosaur pronounce this dinosaur as ee-on-oh-fron in-fur-nal-lis.

The name honours the description of the Anzu taxon as well as the student’s late beloved pet, a Nile monitor lizard named Pharaoh.

Student Kyle Atkins-Weltman.
Oklahoma State University PhD student Kyle Atkins-Weltman. Picture credit: Matt Barnard/OSU Centre for Health Sciences.

Eoneophron infernalis and Implications for Caenagnathid Diversity

Previously, only one caenagnathid (Anzu wyliei) was known from the Hell Creek Formation. It was formally named and described in 2014 (Lamanna et al). Palaeontologists were aware of smaller, fragmentary fossil bones representing caenagnathids from the Hell Creek Formation. It was unclear whether these fossils represented distinct, undescribed taxa or juvenile A. wyliei specimens. Eoneophron infernalis is estimated to have stood around one metre high at the hips and weighed approximately seventy kilograms. In contrast, Anzu wyliei was much larger, with a hip height of about 1.5 metres and weighing three hundred kilograms.

This new taxon is also distinct from other small caenagnathid material previously described from the area. Scientists postulate that there are potentially three distinct caenagnathid genera in the Hell Creek Formation. These results show that caenagnathid diversity in the Hell Creek ecosystem has probably been underestimated.

Caenagnathids of the Hell Creek Formation.
A life reconstruction of Eoneophron infernalis (left), an as yet, undescribed caenagnathid MOR 752 (bottom), and Anzu wyliei (right). Picture credit: Zubin Erik Dutta.

A Feathered Dinosaur

When asked to describe Eoneophron infernalis, Kyle highlighted how closely related to birds these dinosaurs were. He stated:

“It was a very bird-like dinosaur. It had a toothless beak and a relatively short tail. It’s hard to tell its diet because of the toothless beak. It definitely had feathers. It was covered in feathers and had wings.”

Co-author of the scientific paper and Kyle’s faculty advisor Associate Professor Eric Snively commented:

“Kyle is the first student researcher at OSU-CHS to reveal, describe and name a new dinosaur.”

When it looked like the fossils may not belong to an Anzu, Atkins-Weltman turned to caenagnathid researchers Greg Funston, PhD, a palaeontologist with the Royal Ontario Museum in Ontario, Canada, and palaeontology PhD candidate Jade Simons with the University of Toronto for their assistance.

He was also able to involve Associate Professor of Anatomy Dr Holly Woodward Ballard, an expert in bone histology.

A view of the metatarsal bones of Eoneophron infernalis.
A view of the metatarsal bones of Eoneophron infernalis. Picture credit: Kyle Atkins-Weldman.

A Thrilling Discovery

Kyle Atkins-Weltman explained that his project and published findings would not have been possible without his co-authors and those who assisted him.

He added:

“It was really thrilling. Based on the work and research I do, I never thought I would be someone to discover a new dinosaur species.”

Eoneophron infernalis life reconstruction.
Eoneophron infernalis life reconstruction. Picture credit: Zubin Erik Dutta.

Everything Dinosaur acknowledges the assistance of a media release from Oklahoma State University in the compilation of this article.

The scientific paper: “A new oviraptorosaur (Dinosauria: Theropoda) from the end-Maastrichtian Hell Creek Formation of North America” by Kyle L. Atkins-Weltman, D. Jade Simon, Holly N. Woodward, Gregory F. Funston and Eric Snively published in PLOS One.

11 01, 2024

A New Tyrannosaurus Species is Described

By | January 11th, 2024|Adobe CS5, Dinosaur and Prehistoric Animal News Stories, Dinosaur Fans, Main Page, Palaeontological articles, Photos/Pictures of Fossils|1 Comment

Scientists have identified a new species of tyrannosaur from fossils found in western New Mexico. The dinosaur has been named Tyrannosaurus mcraeensis. Although it lived many millions of years before T. rex, it was closely related to it and around the same size.

Tyrannosaurus mcraeensis life reconstruction.
A life reconstruction of Tyrannosaurus mcraeensis with the contemporaneous chasmosaur Sierraceratops in the background. Picture credit: Sergey Krasovskiy.

Tyrannosaurus mcraeensis

The study, published in “Scientific Reports” postulates that the ancestors of T. rex originated in southern Laramidia. Where and when the tyrannosaur lineage that includes T. rex and its closest relatives evolved remains unclear. It had been thought that these theropods originated in Asia, or perhaps at more northerly latitudes of Laramidia. The identification of fossils representing a giant, 12-metre-plus tyrannosaur suggests that large-bodied, apex predators evolved alongside other exceptionally large dinosaurs at lower latitudes.

The researchers examined a partial skull (NMMNH P-3698), that had been excavated from a location in Sierra County, New Mexico. The fossil material consisted of a right postorbital and squamosal, along with a left palatine, a fragmentary maxilla and elements from the lower jaws including the left dentary. The fossils come from Hall Lake Formation (McRae Group). Uranium to lead (U/Pb) isotope analysis of a layer some thirty metres below the tyrannosaur fossil site is dated to 73.2 mya plus or minus 0.7 million years. This indicates that Tyrannosaurus mcraeensis predates T. rex by approximately 6-7 million years.

Skull bones of Tyrannosaurus mcraeensis.
Cranial elements of Tyrannosaurus mcraeensis (NMMNH P-3698). Right postorbital in (A), lateral view; (B), medial view; (C), dorsal view. Right squamosal in (D), lateral view; (E), medial view; (F), ventral view. Note scale bars = 10 cm. Picture credit: Dalman et al.

The skull bones, previously assigned to T. rex are currently on display at the New Mexico Museum of Natural History & Science (NMMNHS).

Views of the Tyrannosaurus mcraeensis mandible
The left dentary of Tyrannosaurus mcraeensis (NMMNH P-3698) in media view (A), lateral view (B) and dorsal view (C). The right spenial in medial view (D) and (E) the right angular in medial view. The right prearticular is shown in medial view (F). Note scale bar = 20 cm. Picture credit: Dalman et al.

Older and More Primitive than Tyrannosaurus rex

While the new discovery predates T. rex, the paper notes that subtle differences in the jaw bones make it unlikely that T. mcraeensis was a direct ancestor. However, it is assigned to the Tyrannosaurini tribe, which is defined by the authors as the last common ancestor of the Asian Tarbosaurus bataar and Tyrannosaurus rex and all its descendants.

Contributing authors on the study include researchers from the University of Bath (UK), NMMNHS, University of Utah, The George Washington University, Harrisburg University, Penn State Lehigh Valley, and the University of Alberta.

Ironically, it was the examination of horned dinosaur fossils from the same palaeoenvironment that led to the discovery of a new Tyrannosaurus species. In 2013, then-student Sebastian Dalman began to re-examine ceratopsian fossils, it led to a broader rethink about the dinosaur fauna associated with the McRae Group.

Dalman commented:

“I started working on this project in 2013 with co-author Steve Jasinski and soon we started to suspect we were on to something new.”

Careful Comparison with T. rex Skull Fossils

Analysis of the skull material revealed subtle, but unique traits relating to their morphology and articulation. Careful comparison with T. rex skull fossils led the research team to conclude that these bones did not represent Tyrannosaurus rex. This was something new.

Comparing skull bones of T. mcraeensis and T. rex.
Comparing skull bones of the newly described Tyrannosaurus mcraeensis and Tyrannosaurus rex. Variation in the postorbitals (A–F), dentaries (G–K) and splenials (M–Q) of Tyrannosaurus mcraeensis (A, G, M) and Tyrannosaurus rex (B–F, H–L, N–Q). Scale bars = 10 cm. Picture credit: Dalman et al.

As T. rex is known from multiple individuals, it is possible to show that T. mcraeensis lies outside of the range of individual variation seen in T. rex.

Co-author of the paper, Dr Anthony Fiorillo, Executive Director of NMMNHS explained:

“New Mexicans have always known our state is special, now we know that New Mexico has been a special place for tens of millions of years. This study delivers on the mission of this museum through the science-based investigation of the history of life on our planet.”

Size estimates for Tyrannosaurus mcraeensis put it in the same bracket as the famous and geologically younger T. rex. It is thought to have measured around twelve metres in length.

Fellow author of the paper, Dr Nick Longrich (Milner Centre for Evolution at the University of Bath) added:

“The differences are subtle, but that’s typically the case in closely related species. Evolution slowly causes mutations to build up over millions of years, causing species to look subtly different over time.”

Tyrannosaurus mcraeensis and the Origins of T. rex

The identification of a new Tyrannosaurus from New Mexico raises the intriguing possibility that there are several more new tyrannosaur discoveries yet to be made.

Co-author Dr Spencer Lucas (Palaeontology Curator at the NMMNHS) stated:

“Once again, the extent and scientific importance of New Mexico’s dinosaur fossils becomes clear. Many new dinosaurs remain to be discovered in the state, both in the rocks and in museum drawers!”

Tyrannosaurus mcraeensis expands our understanding of tyrannosaurs in several ways. Firstly, it suggests that the apex predators lived in what is now the southern United States at least 72 million years ago. Secondly, the Tyrannosaurus genus likely originated in southern North America then later expanded into much of the western portion of the continent.

Phylogenetic analysis supports this hypothesis. The analysis places T. mcraeensis as sister taxon to T. rex and suggests the Tyrannosaurini tribe originated in southern Laramidia.

Tyrannosaurus mcraeensis phylogeny and size comparison with T. rex.
Size, relationships and biogeography of Tyrannosaurus mcraeensis. (A), relative sizes of Tyrannosaurus mcraeensis (NMMNH P-3698) and Tyrannosaurus rex known as “Sue” (FMNH PR 2081) and the type specimen (CM 9380). An evolutionary tree based on Bayesian tip-dated phylogeny and biogeographic analysis. Picture credit: Dalman et al.

Tyrannosaurus mcraeensis Raises More Questions

The skull fossils assigned to T. mcraeensis suggest that larger, more robust and powerful tyrannosaurs evolved in the southern United States compared to the smaller and more primitive tyrannosaurs found further north.

For reasons as yet unknown, dinosaurs may have evolved to larger sizes in lower latitudes in North America. This body condition pattern is not seen in modern mammals. This newly described tyrannosaur was part of an ecosystem dominated by super-sized dinosaurs. For example, the giant chasmosaur Sierraceratops turneri was contemporaneous. In addition, the titanosaur Alamosaurus and an as yet, undescribed giant hadrosaur shared this palaeoenvironment.

Dinosaurs of the Hall Lake Formation.
Dinosaurs of the Campanian-Maastrichtian Hall Lake Formation. Tyrannosaurus mcraeensis (NMMNH P-3698), the horned dinosaur Sierraceratops turneri, a giant but as yet undescribed hadrosaurid and the titanosaur Alamosaurus. Picture credit: Dalman et al.

Giant tyrannosaurs were able to spread north during the Maastrichtian stage of the Late Cretaceous. The reasons for this migration remain unclear. Perhaps the northward spread of giant herbivores such as Triceratops and Torosaurus created a food source that could be exploited by the very biggest tyrannosaurs.

Everything Dinosaur acknowledges the assistance of a media release from the University of Bath in the compilation of this article.

The scientific paper: “A giant tyrannosaur from the Campanian–Maastrichtian of southern North America and the evolution of tyrannosaurid gigantism” by Sebastian G. Dalman, Mark A. Loewen, R. Alexander Pyron, Steven E. Jasinski, D. Edward Malinzak, Spencer G. Lucas, Anthony R. Fiorillo,
Philip J. Currie and Nicholas R. Longrich published in Scientific Reports.

The Everything Dinosaur website: Everything Dinosaur.

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