All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.

Articles, features and information which have slightly more scientific content with an emphasis on palaeontology, such as updates on academic papers, published papers etc.

5 03, 2024

Khinjaria acuta A Bizarre New Mosasaur from Morocco

By |2024-03-10T10:09:18+00:00March 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.

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24 02, 2024

Studying Sea Scorpion Fossils – How Did Eurypterids Breathe?

By |2024-03-16T17:25:24+00:00February 24th, 2024|Adobe CS5, Educational Activities, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

The eurypterids were an extremely successful group of arthropods. These animals are often referred to as “sea scorpions”. However, their taxonomic relationship to extant scorpions remains unclear and they were not confined to marine environments. These invertebrates are members of the Subphylum Chelicerata (claw horns) and are members of the Eurypterida Order. Approximately 250 different species have been named. One of the fascinating aspects of eurypterids is understanding how they breathed.

Examining sea scorpion fossils
A fossil of a sea scorpion (eurypterid) on display at the Manchester Museum. Note the pointed end segment (telson). Probably an example of the Silurian eurypterid Eurypterus. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

How Did Eurypterids Breathe?

Most palaeontologists believe that eurypterids evolved in marine environments. However, fossils have been found in association with estuarine and freshwater environments. Carboniferous trackways suggest that some eurypterids may have been amphibious and able to spend some time on land.

No eurypterid is thought to have been wholly or primarily terrestrial. There is some remarkable fossil evidence to suggest that they did evolve air-breathing organs. When discussing respiration, it is thought that the primary organs of aquatic respiration are likely to have been retained at least in part.

The extant horseshoe crab (Limulus) may provide an analogue. These animals inhabit marine environments although they do venture into shallow water to mate and onto the shore to lay eggs. Horseshoe crabs have five pairs of gills located on their abdomen (Opisthosoma). Each pair of gills consists of flap-like structures covering a series of membranes that resemble the pages from a book. These are called lamellae, but their morphology has given rise to the popular term “book lungs”. Oxygen is absorbed via gaseous exchange on the surface area of the lamellae.

CollectA Horseshoe crab model in ventral view
The CollectA Horseshoe crab model in ventral view (view of the underside). Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The image (above) shows a ventral view of the popular CollectA horseshoe crab model.

To view the range of CollectA models in stock: CollectA Prehistoric Animal Models and Figures.

Four Pairs of Book Gills or Five?

Debate still continues as to whether eurypterids had four pairs of book gills or five. A specimen of Onychopterella augusti from Late Ordovician strata located in South Africa preserved four pairs of vertical book gills. The book gills were located in the third to sixth segments of the abdomen. It has been suggested that all eurypterids had four pairs of book gills rather than the five pairs seen in xiphosurans such as horseshoe crabs.

Terrestrial scorpions also have four pairs of vertically orientated book lungs, located in the third to sixth body segments. It is not known whether this is case of synapomorphy (shared characteristic different from that of their latest common ancestor). This anatomical similarity could indicate that scorpions (Order Scorpiones) are more closely related to eurypterids than previously thought. The phylogenetic relationship between eurypterids and other members of the Arthropoda remains controversial.

Pancaked Sea Scorpion Fossils

Unfortunately, most fossil specimens of eurypterids are squashed flat and may only represent exuviae (shed exoskeletons after moulting [ecdysis]).

Two Pterygotus sea scorpion fossils.
Examples of the Pterygotioidea eurypterid lineage. Note the flattened, blade-like telson that probably helped with propulsion or acted like a rudder helping to steer the animal through the water. The fossils represent Pterygotus anglicus. A pair of beautiful sea scorpion fossils. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

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23 02, 2024

Dinocephalosaurus and the Year of the Dragon

By |2024-02-23T13:53:07+00:00February 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.

Visit the Everything Dinosaur website: Everything Dinosaur.

20 02, 2024

New Lambeosaurine Dinosaur Described from Morocco

By |2024-02-25T07:36:02+00:00February 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 |2024-02-19T12:35:47+00:00February 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.

15 02, 2024

Digging into the History of Burrowing Vertebrates

By |2024-02-16T08:53:17+00:00February 15th, 2024|Dinosaur Fans, Main Page, Palaeontological articles|0 Comments

A newly published scientific paper documents the evolutionary history of burrowing vertebrates. Many animals alive today are able to live underground. Burrows are used for a variety of purposes. They are used for shelter, protection and for breeding. Understanding the origin and early evolution of fossorial vertebrates and the architecture and function of the burrows they excavate is an important component of the history of life on Earth. However, little research has been done into this area of vertebrate behaviour. A newly published scientific paper reviews the fossil record of vertebrate burrows and fossorial vertebrates.

Jehol mammals Fossiomanus sinensis and Jueconodon cheni
Two new species of Early Cretaceous mammals were described from fossils found in north-eastern China. Fossiomanus sinensis (upper right) and Jueconodon cheni in their burrows. A newly published scientific paper reviews the fossil record of burrowing vertebrates. Picture credit: Zhao Chuang.

Picture credit: Zhao Chuang

The Evolution of Burrowing Vertebrates

Scientists including Dr Lorenzo Marchetti and colleagues from the Museum für Naturkunde Berlin analysed both body and trace fossils. The fossil material covered a large interval of geological time, from the Devonian to the Triassic. The research revealed an older appearance of several features related to burrowing behaviour and their relationship with global warming and mass extinctions.

During the Devonian-Carboniferous, burrows were probably used primarily for aestivation or temporary shelter and evidence of fossoriality is restricted so far to European and North American localities. During the Permian, fossoriality became geographically widespread and developed in new, distantly related vertebrate lineages. This is evidence of convergent evolution. Adaptations for burrowing and living underground being identified in both synapsids and diapsids.

The research highlights that lungfish (Dipnoi) were probably the first vertebrates to use burrows. Lungfish excavate burrows so that they have a protected environment in which they can spend long periods in a state of dormancy (aestivation). This behaviour probably first evolved in the Devonian.

Burrows Became Bigger and More Complex

The paper, published in “Earth-Science Reviews” outlines a trend for bigger and more complex burrows during the Palaeozoic and into the Mesozoic. Burrows became permanent shelters and breeding locations. The researchers link these developments to climate crises such as the Cisuralian aridification (Early Permian) and the end-Permian extinction event.

After the end-Permian mass extinction, vertebrate fossoriality became more common and widespread. This behaviour became a feature of continental environments and in more distal floodplain areas, probably as a consequence of changing fluvial regimes. In the Triassic, fossoriality is recorded in even more groups, such as the Temnospondyli and the Procolophonidae. In addition, evidence of burrow sharing by unrelated vertebrates appears. This indicates that burrowers were playing an increasing role as ecosystem engineers.

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

The scientific paper: “Origin and early evolution of vertebrate burrowing behaviour” by Lorenzo Marchetti, Mark J. MacDougall, Michael Buchwitz, Aurore Canoville, Max Herde, Christian F. Kammerer and Jörg Fröbisch published in Earth-Science Reviews.

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13 02, 2024

Studying Stunning Sea Scorpion Fossils

By |2024-03-03T12:39:31+00:00February 13th, 2024|Adobe CS5, Educational Activities, Main Page, Palaeontological articles, Photos/Pictures of Fossils|0 Comments

Eurypterids (Eurypterida) are often referred to as sea scorpions. Like scorpions these extinct invertebrates are members of the Arthropoda Phylum. They are distantly related to extant scorpions and spiders. It is thought that the first eurypterids evolved during the Ordovician. They thrived in the Silurian and Devonian. Giant forms evolved, animals like Jaekeklopterus, Acutiramus and Pterygotus. However, the number of taxa was severely depleted during the end-Devonian extinction event and although they survived for at least another 100 million years or so, during the Carboniferous and Permian they only made up a very small percentage of the taxa described from fossil deposits.

Two Pterygotus sea scorpion fossils.
Examples of the Pterygotioidea eurypterid lineage. Note the flattened, blade-like telson that probably helped with propulsion or acted like a rudder helping to steer the animal through the water. The fossils represent Pterygotus anglicus. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The picture (above) shows two Pterygotus anglicus fossil specimens on display at the London Natural History Museum. These Early Devonian fossils come from Arbroath (Scotland).

The Shape of the Telson

Note the broad, flattened, blade-like final segment of the animal. This is the telson and in the Pterygotioidea lineage (as well as in some other Superfamilies), the telson evolved into an organ to help with propulsion and steering. In other eurypterids, the telson is shaped very differently. For example, in the sea scorpion fossil (below), the telson is long and pointed.

Examining sea scorpion fossils
A fossil of a sea scorpion (eurypterid) on display at the Manchester Museum. Note the pointed end segment (telson). Probably an example of the Silurian eurypterid Eurypterus. Picture credit: Everything Dinosaur.

The Giant Claws (Chelicerae) Seen in Some Sea Scorpion Fossils

The segmented body of eurypterids consisted of the frontal prosoma (head) and the posterior opisthosoma (abdomen). The prosoma contained the mouth and six pairs of appendages which are usually referred to as appendage pairs I to VI using Roman numerals. The segments that make up the opisthosoma are usually numbered using Arabic numerals 1, 2, 3 etc. The opisthosoma comprised twelve segments in total plus the telson.

The first pair of appendages, the only pair located in front of the mouth opening, is called the chelicerae (pronounced kel-iss-ser-ray). This pair of appendages evolved into a myriad of forms in the Chelicerata (pronounced kel-iss-ser-rat-ah), the Subphylum containing the eurypterids, spiders, mites, scorpions and horseshoe crabs. This pair of appendages form the fangs seen in spiders and form the feeding limbs of horseshoe crabs.

An Atlantic horseshoe crab viewed ventrally.
An Atlantic horseshoe crab in ventral view with the six pairs of appendages and the telson labelled. The first pair of appendages (chelicerae) help to push food into the mouth opening. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Powerful Pincers Adapted for Grasping Prey

Some of these appendages, such as the chelicerae of giant pterygotids evolved into powerful pincers armed with strong claws analogous to those seen in crabs and lobsters. These chelicerae seem to be adapted for grasping and subduing prey. This suggests that many eurypterids were predatory.

A sea scorpion claw
A stunning fossil of a sea scorpion (eurypterid) claw housed at the National Museum Cardiff (Wales) photographed in 2019 when team members at Everything Dinosaur visited. The image shows a single chelicera ramus. Picture credit: Everything Dinosaur.

Note

A single appendage is referred to as a chelicera (pronounced kel-iss-ser-rah). Whereas a pair or more are referred to as chelicerae (kel-iss-ser-ray).

A spokesperson from Everything Dinosaur commented that these arthropods were remarkable animals.

“Some 250 different taxa have been described and some of these sea scorpions show adaptations that indicate they may have been partially terrestrial. Venturing out onto land is supported by trace fossils potentially preserving tracks of eurypterids walking across mud close to bodies of water.”

Visit the Everything Dinosaur website: Everything Dinosaur’s Website.

10 02, 2024

Getting to Grips with the Enigmatic Caenagnathidae

By |2024-02-07T10:13:48+00:00February 10th, 2024|Dinosaur and Prehistoric Animal Drawings, Dinosaur Fans, Main Page, Palaeontological articles, Photos of Everything Dinosaur Products, Photos/Pictures of Fossils|0 Comments

With the publication of the scientific paper announcing the discovery of Eoneophron infernalis, we at Everything Dinosaur thought we would take a closer look at the Caenagnathidae. The Caenagnathidae family (pronounced seen-nag-nay-thid-ay), are part of the Oviraptorosauria clade of maniraptoran theropod dinosaurs. They are closely related to the oviraptorids (Oviraptoridae family).

Anzu wyliei scale drawing.
A scale drawing of a dinosaur (Anzu wyliei). This dinosaur is a member of the Caenagnathidae family, and its fossils come from the Hell Creek Formation (Maastrichtian faunal stage of the Late Cretaceous). Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

To read the recent article about Eoneophron infernalis: University Student Discovers New Dinosaur Species.

Defining the Maniraptora and the Oviraptorosauria

The Maniraptora clade consists of coelurosaurian dinosaurs and is defined as including the birds and the non-avian dinosaurs more closely related to them than to Ornithomimus velox. As well as containing the Oviraptorosauria, this clade also includes several other groups such as the dromaeosaurids, the Troodontidae family and the therizinosaurs.

The Oviraptorosauria clade* is comprised of the Caudipteridae family and two closely related dinosaur families the Caenagnathidae and the Oviraptoridae that together are classified as the Caenagnathoidea. The Oviraptorosauria are united by having very bird-like skeletons, with highly pneumatised bones. In addition, the rostrum is very short, and these dinosaurs have beaks. The beak is often, but not always edentulous (no teeth). These dinosaurs were all probably feathered.

A model of an Oviraptor.
An Oviraptor dinosaur model (CollectA Age of Dinosaurs).

The image (above) depicts an Oviraptor model from the CollectA Age of Dinosaurs range.

To view this range of prehistoric animal figures: CollectA Age of Dinosaurs/Prehistoric Life Models.

The Caenagnathidae Family and Eoneophron infernalis

The family Caenagnathidae, together with its closely related sister family the Oviraptoridae, comprises the superfamily Caenagnathoidea. Virtually all known members of this superfamily are confined to the Late Cretaceous. Taxonomically the Caenagnathidae is defined as Chirostenotes pergracilis and all other theropods more closely related to it than they are to Oviraptor philoceratops.

Most of these dinosaurs tend to be quite small. As a result, they are probably underrepresented in the fossil record. For example, Anzu wyliei was thought until recently to be the only caenagnathid from the Hell Creek Formation. However, there are probably at least three caenagnathids present in Hell Creek strata, including the recently named Eoneophron infernalis.

Eoneophron infernalis limb bones
The femur (left) and right tibia (right) of Eoneophron. Picture credit: Kyle Atkins-Weldman.

Caenagnathids Not Closely Related to Ostriches

The Caenagnathidae family was originally erected by Raymond Martin Sternberg (1940), the son of the pioneering palaeontologist Charles Mortram Sternberg. Raymond Martin Sternberg thought that these dinosaurs were flightless birds. He erected the Caenagnathidae family which translates as “recent jaws”. It was mistakenly thought that these theropods were closely related to the Palaeognathae “old jaws” bird family. Extant palaeognath birds include the flightless Kiwi, the Ostrich and the Rhea as well as volant forms such as Tinamou birds. It is now known that the Caenagnathidae family of non-avian dinosaurs are not closely related to palaeognaths.

Caenagnathids are confined to the Late Cretaceous of Asia and North America. They tend to have small heads, long necks and short tails.

Time-calibrated Oviraptorosauria clade consensus tree showing the position of Eoneophron infernalis. Picture credit: Atkins-Weltman et al.

Challenging Phylogenetic Assessment

Whilst the fragmentary nature of most caenagnathid specimens makes phylogenetic assessment challenging, in the recent Eoneophron infernalis paper the researchers undertook a time-calibrated phylogenetic analysis of the Oviraptorosauria. Eoneophron was placed as a sister taxon to Citipes elegans and Elmisaurus rarus.

The difficulties involved in classifying oviraptorosaurs is exemplified by this placement. Although skeletal similarities between these three dinosaurs exist, there is a lack of comparable fossil material to study. Citipes elegans is geologically older. Its fossils come from the Dinosaur Provincial Park Formation of Alberta (Campanian faunal stage of the Late Cretaceous). In contrast, Elmisaurus rarus probably predates Eoneophron infernalis by a couple of million years. It too is from the Maastrichtian faunal stage of the Cretaceous. However, E. rarus fossils come from the Nemegt Formation of Mongolia.

A revision of already described specimens coupled with improved fossil sampling should help palaeontologists to gain a better understanding of the taxonomy of the Oviraptorosauria and specifically the enigmatic Caenagnathidae.

The Oviraptorosauria clade* also includes some other theropods regarded as basal members of this clade. For example, Incisivosaurus gauthieri from the Early Cretaceous of China.

Visit the Everything Dinosaur website: Everything Dinosaur.

7 02, 2024

New Research into Dinosaur Locomotion

By |2024-02-08T08:32:20+00:00February 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 |2024-02-06T13:45:11+00:00February 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.

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