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.

29 07, 2026

Newly Described Sauropodomorph from the Late Triassic of Zimbabwe

By |2026-07-28T15:50:35+01:00July 29th, 2026|Categories: Palaeontological articles|0 Comments

A team of international researchers have described a new dinosaur based on fossils found in Zimbabwe. This newly described sauropodomorph named Musango matusadonaensis lived during the Late Triassic (Norian faunal stage), around 210 million years ago. Musango is the fifth dinosaur to be named from fossils discovered in Zimbabwe. Furthermore, these fossils further support the idea of distinct dinosaur communities in southern Africa during the Late Triassic. Previously, scientists had thought that there were close faunal and biostratigraphical links between the Late Triassic vertebrate faunas of Zimbabwe and South Africa. Currently, no dinosaur taxa are shared between the Triassic-aged sedimentary units in Zimbabwe and those of the main Karoo Basin of South Africa and Lesotho.

Musango matusadonaensis life reconstruction.

A life reconstruction of the fifth dinosaur to be named from fossils found in Zimbabwe (Musango matusadonaensis). Picture credit: Mark Witton.

Picture credit: Mark Witton

The fossils were discovered on the shores of Lake Kariba in northern Zimbabwe. Moreover, the find provides fresh evidence that southern Africa preserves an important record of early dinosaur evolution.

Musango matusadonaensis – A New Member of the Sauropodomorpha

Musango matusadonaensis is classified as an early member of the Sauropodomorpha, a group of dinosaurs that eventually gave rise to giant, long-necked herbivores such as Brachiosaurus and Diplodocus. However, unlike its enormous descendants, M. matusadonaensis was a relatively small, lightly built dinosaur that probably walked on two legs. The fossils were found in association with each other but not articulated. The material consists of a partial skeleton consisting of five dorsal vertebrae, two sacral vertebrae, a left scapula and coracoid along with a partial left ilium; a right pubis and elements from the limbs. In addition, several indeterminate bone fragments were recovered.

The absence of a femur makes size estimation difficult.  However, based on comparisons with other Late Triassic sauropodomorphs, the specimen (NHMZ 2583) represents a four and a half metre long individual.  This dinosaur is estimated to have weighed around 220 kilograms.

Musango matusadonaensis silhouette showing known fossil material.

Musango matusadonaensis silhouette showing known fossil material. Scale bar equals 1 metre. Picture credit: Brandon Stuart with additional annotation by Everything Dinosaur.

Picture credit: Brandon Stuart with additional annotation by Everything Dinosaur

While the skull has not yet been found, researchers believe that Musango was probably herbivorous or perhaps omnivorous.

Revealing Ancient African Ecosystems

The Late Triassic was a pivotal period in Earth’s history. Dinosaurs had evolved, but they had not yet become the dominant terrestrial vertebrates they would be during the Jurassic and Cretaceous. For many years, scientists assumed that dinosaur faunas across southern Africa were broadly similar. However, discoveries from Zimbabwe are beginning to challenge this long-held view.

Professor Paul Barrett, Merit Researcher at the Natural History Museum, London, and the study’s lead author, commented:

“Until recently, it was assumed that the dinosaurs living across southern Africa were largely the same. However, these discoveries are showing that this part of the ancient supercontinent Gondwana was actually made of a series of smaller ecosystems – each with a different cast of characters.”

Professor Paul Barrett (London Natural History Museum) carefully excavating fossil material.

Professor Paul Barrett (London Natural History Museum) carefully excavating fossil material on the shores of Lake Kariba. Picture credit: Paul Barrett.

Picture credit: Paul Barrett

The Fifth Dinosaur to be Described from Zimbabwe

The first dinosaur to be named from Zimbabwe was the coelophysoid “Syntarsus” rhodesiensis which was formally named and described in 1969. However, the genus name was already assigned, so it was moved to the genus Megapnosaurus, although the fossils may represent a species of Coelophysis.

The five dinosaurs known from Zimbabwe:

  1. “Syntarsus” – Megapnosaurus (possibly Coelophysis) – a small theropod dinosaur.
  2. Vulcanodon karibaensis – a primitive sauropod.
  3. Mbiresaurus raathi – a basal sauropodomorph named in 2022 that is geologically older than Musango matusadonaensis (Griffen et al).
  4. Musankwa sanyatiensis – a basal sauropodomorph named in 2024 (Barrett et al) which was coeval with M. matusadonaensis.
  5. Musango matusadonaensis (Barret et al, 2026).

To read our article from 2024 about Musankwa sanyatiensis, the fourth dinosaur to be described from Zimbabwe: A New Sauropodomorph from Zimbabwe (2024).

The discovery of several sauropodomorphs in this locality highlights the significance of southern Africa to researchers examining the evolution of the sauropod lineage.

Analysis of the Musango fossil bones indicates that the individual was around eight years old and approaching full adult size when it died. Interestingly, the skeleton also preserves evidence that the dinosaur survived a serious injury or infection during its lifetime. This suggests it recovered successfully before eventually dying from another cause.

Life in an Ancient River Ecosystem

During the Late Triassic, the landscape of present-day Zimbabwe looked very different from today. Rivers and streams crossed the region, supporting a wide range of plants and animals. Musango matusadonaensis shared its habitat with lungfish, crocodile-like phytosaurs and other dinosaurs, including Musankwa sanyatiensis. As fieldwork continues, researchers expect many more species to emerge from these fossil-rich rocks.

Professor Paul Barrett believes these discoveries are only the beginning:

“It suggests that what we’ve found so far is only the tip of the iceberg. We’ve already got one other new species that we’ve yet to describe, while our team has been told about other fossils from the region that we’ve yet to look at. I think it’s likely there are even more dinosaurs still to be found there.”

Musango ilium.

The ilium of the newly described sauropodomorph from Zimbabwe (Musango matusadonaensis). Picture credit: Brandon Stuart.

Picture credit: Brandon Stuart

An International Scientific Collaboration

The research forms part of an ongoing collaboration between scientists from Zimbabwe, South Africa and the United Kingdom. Together, they are exploring regions that have received relatively little palaeontological attention compared to Europe, China and North America. As a result, these discoveries are helping fill important gaps in the fossil record. They also demonstrate that Africa played a significant role in the early evolution and diversification of dinosaurs.

Professor Jonah Choiniere, leader of the expedition and a co-author from Johannesburg’s Evolutionary Studies Institute, explained:

“New dinosaur species like Musango show the value of doing palaeontological fieldwork in remote, and often scenically beautiful, places. This study is the result of a thriving international collaboration between the UK, South Africa and Zimbabwe, and reinforces the importance of southern Africa in understanding dinosaur diversity.”

Musango matusadonaensis Etymology

The name of this new dinosaur reflects both the local language and the discovery site. Musango comes from the ChiShona language and means “living in the bush”, referring to the remote location where the dinosaur was unearthed. Meanwhile, the species name honours the nearby Matusadona National Park.

The discovery of the fifth dinosaur from Zimbabwe adds another important piece to the puzzle of dinosaur evolution. Moreover, it highlights the scientific importance of the country’s fossil record. As exploration continues, palaeontologists hope that many more prehistoric species will emerge from this remarkable part of Gondwana.

Everything Dinosaur acknowledges the assistance of a media release from the London Natural History Museum in the compilation of this article.

The scientific paper: “A new sauropodomorph dinosaur from the Pebbly Arkose Formation (Upper Triassic: Norian) of Kariba, Zimbabwe” by Paul M. Barrett, Jennifer Botha, Lara Sciscioe, Brandon P. Stuart, Jack Lovegrove, Darlington Munyikwa, Michel Zondo, Timothy J. Broderick, Steve F. Edwards, Edward Mbambo, Kimberley E. J. Chapelle, Kathleen N. Dollman, Steve Tolan and Jonah N. Choiniere published in the Journal of Systematic Palaeontology.

The award-winning Everything Dinosaur website: Sauropod Models and Dinosaur Figures.

28 07, 2026

Queensland Ichthyosaur Fossil Provides World-first Evidence of Predation on a Pterosaur

By |2026-07-29T15:51:13+01:00July 28th, 2026|Categories: Palaeontological articles|0 Comments

An extraordinary fossil from Queensland, Australia has provided evidence of a prehistoric food chain. Scientists have identified the first definitive evidence that an ichthyosaur consumed a pterosaur. Furthermore, the marine reptile later became prey for one of the largest predators in the ancient Eromanga Sea.

The spectacular fossil comes from the Lower Cretaceous Toolebuc Formation of Queensland. It provides an exceptionally rare glimpse into predator-prey relationships that occurred more than 100 million years ago. The research has been published in the journal “Gondwana Research”.

Life reconstruction illustrating the ichthyosaur ate a pterosaur paper.

A life reconstruction showing the ichthyosaur with a pterosaur in its jaws with a Kronosaurus attacking from below. Picture credit: Peter Trusler.

Peter credit: Peter Trusler

An Ichthyosaur with an Extraordinary Tale to Tell

The specimen represents an adult Platypterygius australis. This ichthyosaur measured around six to seven metres in length. Although ichthyosaurs are often compared to modern dolphins because of their streamlined bodies, they were reptiles and not mammals. Their similarity to cetaceans is an example of convergent evolution.

Scientists recovered the fossil from the famous marine deposits near Richmond (Queensland). Nicknamed “B.O.B.” (Bag of Bones), the fossil was first discovered by amateur fossil hunters during a public fossicking trip in 2019. Later excavations uncovered much more of the skeleton, and museum staff invested hundreds of hours preparing the remarkable specimen.

Ichthyosaur ate a pterosaur fossil block in situ.

The ichthyosaur specimen block in situ. Picture credit: White et al.

Picture credit: White et al

Examining the Gut Contents

The real surprise came from several unusual rock concretions preserved immediately behind the skull. Rather than breaking them open, researchers used neutron tomography to examine their contents without damaging the fossils. This advanced imaging technique revealed fragments of fish, cephalopods and two pterosaur bones, including part of a lower jaw.

Careful comparisons showed that the jaw belonged to a member of the Ornithocheiroidae, a group of large flying reptiles. This represents the first definitive fossil evidence that an ichthyosaur had eaten a pterosaur or at least part of one.

Graphical illustration of the food web.

Dietary insights from a dismembered Platypterygius from the Lower Cretaceous of Queensland. Picture credit: White et al.

Picture credit: White et al

The Ichthyosaur Predator Becomes Prey

However, the story did not end there.

The ichthyosaur’s skeleton preserves numerous massive bite marks. Several vertebrae are crushed or split apart, while other bones show signs of powerful jaw action. Some damaged vertebrae even have missing sections, suggesting that the carcass was actively processed rather than simply bitten.

Based on the size and spacing of the bite marks, the researchers conclude that the giant pliosaur Kronosaurus queenslandicus was almost certainly responsible. At around ten metres in length, Kronosaurus was one of the largest marine predators living in Australia’s inland sea during the Early Cretaceous.  It was an apex predator.

An Ichthyosaur Ate a Pterosaur Then Became a Meal For a Larger Marine Reptile

Fossils usually tell palaeontologists what extinct animals looked like. Direct evidence of behaviour is much harder to find in the fossil record.

However, this amazing marine reptile specimen preserves evidence of a sequence of ecological interactions:

  1. Ornithocheiroidae pterosaur.
  2. Platypterygius australis consumed the pterosaur.
  3. Subsequently the ichthyosaur was predated upon by a much larger animal (Kronosaurus queenslandicus).

In other words, the flying reptile became food for the ichthyosaur. Subsequently, the ichthyosaur itself became food for a giant pliosaur (most likely). Therefore, this fossil provides one of the clearest examples yet discovered of a three-tier marine food web from the Mesozoic.

Co-author of the paper Kevin Petersen (Kronosaurus Korner) stands next to the cut slabs containing the ichthyosaur fossil.

Co-author of the paper Kevin Petersen (Kronosaurus Korner) stands next to the cut slabs containing the ichthyosaur fossil. Picture credit: White et al.

Picture credit: White et al

Rare Evidence of Ancient Behaviour and Interactions

Commenting on the discovery, Dr Dean Lomax, a world-renowned expert on the Ichthyosauria and a chum of Everything Dinosaur explained that fossils preserving behaviour are exceptionally uncommon.

Dr Lomax added:

“It’s one of the clearest examples ever discovered of a three-tier predator interaction and offers an unprecedented snapshot of behaviour in Australia’s Cretaceous seas. This extraordinary fossil records a trophic interaction between a pterosaur eaten by an ichthyosaur that was then partly consumed by a giant pliosaur. It gives us direct evidence of behaviour in the Eromanga Sea.”

Platypterygius skull in situ.

Platypterygius skull in situ. Picture credit: White et al.

Picture credit: White et al

Ichthyosaur Ate a Pterosaur

During the Early Cretaceous, much of inland Queensland lay beneath the vast Eromanga Sea. This warm inland sea supported sharks, turtles, marine reptiles and numerous other predators. The new discovery shows that these ancient ecosystems were far more complex than scientists once appreciated. Instead of simple predator-prey relationships, the fossil captures a dynamic food web in which even successful hunters could quickly become victims themselves. In this instance, an ichthyosaur ate a pterosaur only for a larger animal to attack and partially consume the marine reptile.

In addition, the discovery highlights the scientific importance of public fossil collecting sites. Thanks to the curiosity of four fossil enthusiasts, one of Australia’s most significant marine reptile discoveries has provided a unique insight into life beneath the Cretaceous seas.  Indeed, the preserved gut contents of the P. australis specimen indicate that this ichthyosaur consumed fish, cephalopods and ate two pterosaur bones, including a fragment of jaw.

Dr Peter Trusler produced scientific artwork for the paper, updating depictions of Kronosaurus skull proportions and illustrating the ichthyosaur and pterosaur interaction. The prepared specimen (nicknamed “B.O.B.” – after the Bag of Bones epithet) is curated at Kronosaurus Korner Museum.

A Remarkable Snapshot of Prehistoric Marine Life

This exceptional fossil preserves far more than the skeleton of a marine reptile. It captures a sequence of events that unfolded over 100 million years ago and provides direct evidence of feeding behaviour that had never been documented before.

As imaging technology continues to improve, palaeontologists are uncovering increasingly detailed evidence of how extinct animals interacted with one another. Fossils such as this demonstrate that prehistoric ecosystems were every bit as complex as those found in today’s oceans.

Dr Matt White, Research Associate at the University of New England and lead author of the study and a self-funded palaeontologist said the fossil was unlike anything the team had seen before.

He stated:

“I was amazed by the size of the ichthyosaur, and shocked to see it littered with bite marks and partially exposed pterosaur remains behind the skull. The vertebrae were split; ribs were missing and numerous bones displayed large crushing bite marks. One vertebra even preserved a rib jammed against a broken margin, strongly suggesting forceful jaw processing rather than simple post-mortem damage. This discovery enriches our understanding of these ancient marine reptiles and illustrates the complex interactions that shaped their prehistoric aquatic environment. The public fossicking areas near Richmond have yielded thousands of fossils over the years, including dinosaurs, birds, turtles, polycotylid plesiosaurs, pliosaurs, pterosaurs and other marine reptiles.”

Highlighting the Fossil Evidence

The scientific paper documenting an ichthyosaur ate a pterosaur includes a series of helpful graphics that explains how the researchers identified the food web evidence.  For example, three-dimensional mesh images highlight the location of damaged ichthyosaur bones and provide images of the pterosaur dentary.

Figure specimens from the ichthyosaur at a pterosaur paper.

Three-dimensional mesh images of KK F1435 with bite marks and stomach content. (a) Near-complete skull; (b) Stomach content block; (c) articulated autopodium; (d) Basiosphenoid, seven dorsal vertebrae, an isolated neural spine, five partial ribs, left scapula, humerus, and ten isolated digits; (e) Two complete dorsal vertebral centra (one with articulated neural spine) and five partial dorsal vertebral centra that preserve bite marks (v1 and v3), one vertebral centra is shattered; (f) One complete dorsal vertebra, possibly six other shattered dorsal vertebrae along with portions of their neural spines, and one split vertebrae with a rib deformed against the fractured edge (v2); (g) Semi-articulated pre-flexural caudal vertebrae primarily consisting of mostly of pre-flexural vertebrae and a few scattered post-flexural vertebrae; (h) Silhouettes of the approximate in situ position of each block. Abbreviations: b, basisphenoid; f, femur; h, humerus, ip, ischiopubis; n, neural spine; p, phalanx; r, rib; s, scapula, sc stomach content; v1-v3 dorsal vertebral centra with tooth marks. Picture credit: White et al.

Picture credit: White et al

Improving Understanding of Cretaceous Marine Food Webs

As research continues and methodologies advance, each fossil discovery, like this Platypterygius australis, has the potential to reveal more intricate patterns and provide glimpses into the complex food webs that existed beneath the waves during a pivotal time in Earth’s history.

Everything Dinosaur acknowledges the assistance of a Dinosaur Experiences Australia media release in the compilation of this article.

The scientific paper: “Beneath the waves: “Extraordinary dietary insights from a dismembered ichthyosaur from the lower Cretaceous” by Matt Andrew White, Joseph John Bevitt, Mackenzie Jordan Enchelmaier, Kevin William Petersen and Peter William Trusler published in Gondwana Research.

The award-winning Everything Dinosaur website: Models of Marine Reptiles and Other Prehistoric Animals.

22 07, 2026

New Research Examines Sauropod Rearing Behaviour

By |2026-07-22T18:05:47+01:00July 22nd, 2026|Categories: Palaeontological articles|0 Comments

Could giant sauropod dinosaurs stand up on their hind legs? A newly published study has explored this long-debated question using advanced digital biomechanical modelling. The research suggests that although many sauropods were capable of rearing up, the largest species probably found it much more difficult to maintain this posture.  The paper published as an open-access article in the journal “Palaeontology”, is the first to use finite element analysis (FEA) to examine sauropod rearing behaviour.

CollectA rearing Diplodocus (grey). Research into Diplodocus feeding habits.

A model depicting a rearing Diplodocus.  This is the 2020 CollectA Age of Dinosaurs rearing Diplodocus model. Previous studies (Mallison, 2011) had proposed that Diplodocus with its centre of mass located posteriorly may have been able to rear up more easily than other taxa. However, these results provide no strong evidence to indicate that rearing was a frequent behaviour for Diplodocus. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Sauropods, such as Diplodocus, Giraffatitan, Dreadnoughtus and Patagotitan, were the some of the largest terrestrial animals to have ever lived. Their immense size, long necks and pillar-like limbs have fascinated palaeontologists for more than a century. One of the enduring questions surrounding these giants is whether they could raise themselves into a bipedal or tripodal stance. Sauropod rearing behaviour may have occurred to permit them to reach higher branches in trees to feed. In addition, adopting a rearing pose may have helped to intimidate rivals or to defend themselves from carnivorous theropods. Perhaps rearing behaviour could have played role in social display, courtship or mating.

Haolonggood HLG 185c Sauroposeidon Heterochromatic version.

A Haolonggood Sauroposeidon figure depicted in a tripodal rearing pose.  The dinosaur’s huge weight is supported by its massive hind legs and muscular tail.  However, the new study concludes that larger sauropods were probably less capable of maintaining a rearing pose for sustained periods.

Testing Sauropod Rearing Behaviour

The new study, published in the journal Palaeontology, examined the hind limb biomechanics of seven sauropod genera representing a range of sizes and evolutionary groups. Rather than relying solely on skeletal anatomy, the researchers created detailed three-dimensional digital models of the femora (thigh bones) and subjected them to finite element analysis (FEA). This engineering technique predicts how a structure responds to forces and stresses and is widely used in the design of buildings, aircraft and vehicles.

The seven sauropod genera included in the study:

  1. Amargasaurus – a dicraeosaurid known from the Early Cretaceous of Argentina estimated to have reached a length of 12 metres and weighing 5 tonnes.
  2. Australotitan – of the Somphospondyli clade from the Late Cretaceous of Australia with some estimates suggesting a body length around 30 metres and weighing more than 50 tonnes.
  3. Diplodocus – a diplodocid from the Late Jurassic of North America reaching a length of around 27 metres and weighing an estimated 10-20 tonnes.
  4. Dreadnoughtus – a lithostrotian titanosaur from the Late Cretaceous of Argentina approximately 26 metres long and weighing 48-49 tonnes.
  5. Giraffatitan – a brachiosaurid from the Late Jurassic of Tanzania estimated to reach a length of 23 metres and to weigh over 40 tonnes.
  6. Neuquensaurus – a saltasaurid from the Late Cretaceous of Argentina estimated to reach a length of around 9 metres and to weigh 3.5 tonnes.
  7. Uberabatitan – a lithostrotian titanosaur known from the Late Cretaceous of Brazil around 26 metres in length and weighing more than 30 tonnes.

Our detailed guide explaining whether sauropods could stand on their hind legs will be published shortly.

Two Different Femora Load Scenarios

The scientists modelled two different loading scenarios. One simulated how the femora would respond to the animal’s body weight during a rearing posture. The second incorporated the forces generated by the surrounding muscles. By comparing the stress experienced by each femur, the team assessed how well different sauropods may have coped with standing on their hind limbs.

Extrinsic functional scenario modelled in the study Sauropoda rearing study.

Extrinsic functional scenario modelled in the study. A, 3D rendering of the femur of Uberabatitan (CPPLIP-1238) in posterior view, with the red arrow showing the position of the applied loads. B, representation of the constraints (yellow circles) applied to all models for the extrinsic scenarios. Picture credit: Silva Junior et al. (2025), Palaeontology. Reproduced under the terms of the applicable Creative Commons licence.

Picture credit: Silva Junior et al. (2025), Palaeontology. Reproduced under the terms of the applicable Creative Commons licence.

Smaller Sauropods Had an Advantage

The results indicate that body size played a major role in determining how effectively a sauropod could rear up. Smaller species generally experienced lower levels of stress within their femora. In particular, the saltasaurid titanosaur Neuquensaurus performed exceptionally well in the simulations. Its relatively robust femur and favourable muscle attachment sites suggest that it may have been capable of maintaining a rearing posture for longer periods.

In contrast, enormous titanosaurs such as Dreadnoughtus experienced much higher levels of stress within their hind limbs. This finding suggests that although these giants may have been able to rear briefly, maintaining such a posture would have placed considerable demands on their skeleton.

Juveniles may have been more capable of rearing than adults.  This opens up the intriguing possibility of sauropod rearing behaviour permitting ontogenetic niche partitioning. Sauropods may have changed their rearing behaviour as they grew and matured.

Interestingly, the study also compared Diplodocus and Giraffatitan, two sauropods that have featured prominently in previous discussions about rearing behaviour. The new biomechanical analysis broadly supports earlier research suggesting that differences in body shape and centre of mass influenced how easily these dinosaurs could adopt an upright stance. For example, the researchers conclude that Diplodocus was more capable of rearing than a brachiosaur such as Giraffatitan. However, the stress forces in the femur were still relatively high. Therefore, the study authors postulate that rearing for a Diplodocus was not a routine or frequent behaviour.

Giraffatitan brancai on display at the Museum für Naturkunde Berlin.

The giant Giraffatitan brancai skeleton on display at the Museum für Naturkunde Berlin. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Sauropod Rearing Behaviour Probably More Than Just Feeding

For many years, palaeontologists have suggested that rearing allowed sauropods to browse vegetation beyond the reach of other herbivores. However, the researchers point out that this behaviour may also have served several other important functions.

Standing upright could have helped during defensive displays, combat between rivals or mating. Furthermore, the authors note that sauropods may not always have reared unsupported. Leaning against a tree while feeding, or using a mate for additional support during courtship, would have reduced the stresses acting on the hind limbs.

Femora stress results of genera from sauropod rearing study.

Finite element analysis of stress on femora with applied load of 24,500 N to sauropod femora in anterior (left) and posterior (right) views of: Amargasaurus (A); (B), Australotitan; (C), Diplodocus; (D), Dreadnoughtus; (E), Giraffatitan; (F), Neuquensaurus and Uberabatitan (G). Regions displayed in white indicate stress value that exceed the upper limit of the defined scale. Picture credit: Silva Junior et al. (2025), Palaeontology. Reproduced under the terms of the applicable Creative Commons licence.

Picture credit: Silva Junior et al. (2025), Palaeontology. Reproduced under the terms of the applicable Creative Commons licence.

A New Perspective

This is the first study to use finite element analysis specifically to investigate sauropod rearing behaviour. As with any computer model, there are limitations. The digital reconstructions do not include the complex internal structure of bone or the cushioning effects of cartilage. Consequently, the stress values should be viewed as comparative rather than absolute.

Nevertheless, the research provides fresh insight into the lives of the largest terrestrial animals known to science. Rather than treating all sauropods alike, the study demonstrates that anatomy, body size and muscle configuration all influenced their ability to rear up. The findings suggest that some smaller sauropods may have been surprisingly agile, while the largest species were constrained by the sheer scale of their bodies.

Commenting on the research, Mike from Everything Dinosaur explained:

“Sauropods have always challenged our understanding of biomechanics. After all, there are no extant animals analogous to them. This study shows how modern digital techniques can test ideas that were once based largely on educated guesswork. It demonstrates that even among the giant sauropods, anatomy mattered, and not every species would have behaved in exactly the same way.”

The study provides another excellent example of how engineering, computer modelling and palaeontology are working together to answer questions about dinosaur behaviour that would have seemed impossible to investigate just a few decades ago.

The scientific paper: “Standing giants: a digital biomechanical model for bipedal postures in sauropod dinosaurs” by Julian C. G. Silva Junior, Gabriel S. Ferreira, Agustín G. Martinelli, Thiago S. Marinho, Felipe C. Montefeltro published in the journal Palaeontology.

Models of sauropods and other prehistoric animals: Sauropod and Other Dinosaur Models.

20 07, 2026

Earliest Synapsid Cloaca Revealed by 294-Million-Year-Old Fossil

By |2026-07-15T16:30:00+01:00July 20th, 2026|Categories: Palaeontological articles|0 Comments

A remarkable trace fossil from Germany has provided the oldest known evidence of a cloaca in the mammalian lineage. The discovery helps palaeontologists better understand the evolution of early terrestrial vertebrates and fills an important gap in the fossil record. The fossil comes from the famous Bromacker fossil locality in Thuringia (Germany). Among footprints and other trace fossils the scientists identified a tail impression. The anterior portion of this tail impression preserves evidence of the earliest synapsid cloaca.

The international team of researchers, led by scientists from the Museum für Naturkunde Berlin, published their findings in the journal “iScience”. The trace fossils are approximately 294 million years old (Early Permian). This represents the first occurrence of a cloaca in the fossil record of stem mammals.

Earliest synapsid cloaca identified in Bromacker locality trace fossil.

The trace fossil specimen MNG 13490 with the preserved underside of the tail impression. Note scale bar equals 10 cm. Picture credit: Marchetti et al.

Picture credit: Marchetti et al

A Rare Glimpse of Soft Tissue Preservation

Fossils usually preserve bones and teeth. Soft tissues, however, almost always decay before fossilisation can occur. Consequently, direct evidence of anatomical features such as the cloaca is exceptionally rare. The newly described specimen includes a beautifully preserved impression of the tail together with fossil footprints. Near the base of the tail, the researchers identified two rows of raised scales separated by a narrow vertical slit. They interpret these features as the lips and opening of a cloaca.

This fossil provides the first direct evidence of an earliest synapsid cloaca, offering scientists an unprecedented look at the anatomy of an animal closely related to the ancestors of mammals.

Caseid synapsid tail impression.

The caseid synapsid tail impression. Note scale bar equals 5 cm. Picture credit: Marchetti et al.

Picture credit: Marchetti et al

What is a Cloaca?

A cloaca is a single external opening used by the digestive, urinary and reproductive systems. Today, amphibians, reptiles and birds possess a cloaca. Among mammals, however, only monotremes such as the platypus and echidnas have retained this feature. Most extant mammals (placentals and marsupials) have separate openings for these bodily functions. Until now, scientists had little direct fossil evidence showing how this important anatomical structure appeared in the mammalian lineage.

An Early Relative of Mammals

The fossil traces have been linked to a caseid synapsid. Caseids were large-bodied, herbivorous members of the Synapsida, the evolutionary group that eventually gave rise to the Mammalia. Researchers matched the fossil impression with the distinctive Dimetropus footprints found at the Bromacker locality. Comparisons with skeletal fossils collected from the same site strengthened this interpretation.

Although caseids looked very different from mammals today, they belonged to the same broad evolutionary lineage. Therefore, this discovery provides valuable information about the early stages of mammalian evolution.

A close view of the earliest synapsid cloaca.

The cloacal area in the anterior part of the tail impression. Note scale bar equals 5 cm. Picture credit: Marchetti et al.

Picture credit: Marchetti et al

New study highlights the growth rates of diminutive Dimetrodon species from the Bromacker locality: Bromacker Dimetrodon Growth Study.

Why Did the Cloaca Evolve?

The study also explores why the cloaca changed during vertebrate evolution. Although the answer remains uncertain, the researchers suggest several possible explanations.

For example, changes in reproductive anatomy may have played a role. Likewise, increasingly dry environments could have influenced the evolution of different body structures. The scientists also propose that evaporative cooling through the cloacal opening may have helped animals regulate their body temperature. Furthermore, changes in body shape, including shorter tails and modified limbs, may have contributed to these evolutionary developments.

In squamates and birds, the cloaca tends to have a horizontal orientation. Cloacal evaporation for thermoregulation purposes has been observed in squamates and birds. In contrast, the Crocodylomorpha and the Caudata (salamanders and their extinct relatives), have a vertical cloaca. These animals are associated with aquatic environments. Intriguingly, the fossilised tail impression is clearly impressed in a water-saturated sediment.

The fossil specimen shows swimming traces associated with Dimetropus footprints. Therefore, it is possible that a transition from a vertical to a horizontal cloaca occurred as an adaptation to drier environments. The horizontal orientation of the cloacal orifice could favour more efficient cloacal evaporation to help maintain body temperature. This would be in agreement with the vent orientation change in stem reptiles between the Carboniferous and the Permian, in a time of global warming and increasing aridity and seasonality. Nevertheless, the causes of this correlation should be further investigated in modern taxa.

The Significance of the Bromacker Fossil Site

The Bromacker fossil locality is recognised as one of the world’s most important Late Palaeozoic fossil sites. It has produced an exceptional record of terrestrial animals and plants that lived during the Early Permian. This latest discovery also demonstrates the value of revisiting historic museum collections. Modern imaging techniques and careful re-examination can reveal important anatomical details that earlier researchers could not detect.

False-colour depth map of the cloacal area.

A false-colour depth map of the cloacal area taken from the photogrammetric 3D model. Picture credit: Marchetti et al.

Picture credit: Marchetti et al

Understanding the Evolution of Mammals

The discovery of the earliest synapsid cloaca provides much more than an anatomical curiosity. It offers scientists a rare opportunity to investigate the evolution of reproductive and excretory systems in one of the most important vertebrate lineages. As new discoveries emerge from the Bromacker site and other fossil localities, researchers will continue to refine our understanding of how the ancestors of mammals adapted to life on land hundreds of millions of years ago.

Commenting on the importance of this research, Mike from Everything Dinosaur stated:

“Soft tissue fossils are incredibly rare, so discoveries like this earliest synapsid cloaca impression are exceptionally important. The specimen shows that trace fossils can preserve anatomical details that skeletal remains alone cannot reveal. It also reminds us that remarkable scientific discoveries can still be made by re-examining specimens already held in museum collections.”

This remarkable discovery demonstrates how exceptional fossil preservation continues to reveal new chapters in the evolutionary history of the Mammalia.

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

The scientific paper: “The evolutionary significance of the earliest cloacal opening in Synapsida” by Lorenzo Marchetti, Antoine Logghe, Arnaud Rebillard, Mark J. MacDougall and Jörg Fröbisch published in IScience.

The multi-award-winning Everything Dinosaur website: Models of Prehistoric Life.

16 07, 2026

Seal Underwater Hearing Explained by New Research

By |2026-07-15T11:40:13+01:00July 16th, 2026|Categories: Palaeontological articles|0 Comments

A team of international scientists has uncovered the remarkable mechanism behind seal underwater hearing. A new study, led by researchers from the London Natural History Museum reveals how extant seals hear equally well in air and underwater. The findings help to explain a long-standing evolutionary mystery and could support future conservation efforts.

The research, published as an open-access paper in the “Royal Society Proceedings B”, examined more than two hundred living and fossil seal specimens. By combining advanced CT scanning with evolutionary analysis, the researchers identified the specialised tissue that makes this extraordinary ability possible.

Blood-Filled Tissue Helps Seals Hear Underwater

Unlike humans and most other land mammals, seals can hear efficiently in two very different environments. Normally, mammalian hearing relies on an air-filled middle ear. However, this arrangement performs poorly underwater because the air pocket behind the eardrum reflects almost all sound. The researchers discovered that seals overcome this problem with specialised cavernous tissue inside the middle ear. During a dive, this tissue fills with blood. As blood has a density similar to seawater, sound passes more efficiently through the ear and reaches the cochlea. As a result, seals continue to hear clearly beneath the waves.

Lead and corresponding author Dr James Rule (London Natural History Museum/Monash University) explained that scientists have puzzled over this adaptation for decades. The new research finally identifies the anatomical feature responsible for amphibious hearing.

New study helps to explain seal underwater hearing.

A 3D rendering of the skull of a Southern Elephant seal showing the underwater hearing adaptations. Picture credit: James Rule.

Picture credit: James Rule

Fossils Reveal the Evolution of Seal Underwater Hearing

The team’s analysis included both living species and fossil relatives of modern seals. Consequently, the researchers could trace when this remarkable adaptation first evolved. Evidence suggests that the ancestors of seals initially heard well only in air. Ancient species such as Potamotherium (Oligocene to Miocene) and the stem pinniped Puijila (late Oligocene to early Miocene) probably lacked effective underwater hearing. However, later marine relatives, including Enaliarctos, appear to have evolved the first form of amphibious hearing approximately 26.7 million years ago.

Puijila (seal ancestor) life reconstruction.

The earliest relatives of pinnipeds, such as the 23-million-year-old Puijila darwini, could only hear in-air. Like most mammals, their ears did not function properly underwater. Picture credit: Jaime Bran.

Picture credit: Jaime Bran

From this point onwards, different seal groups continued to refine their hearing. For example, true seals (phocids) developed enhanced underwater hearing. In contrast, the earliest eared seals retained adaptations that favoured hearing in air.

The study indicates that these improvements evolved independently after the earliest marine pinnipeds had already acquired the basic mechanism for hearing in both environments.

Rare Acoustic Abilities

The scientists also suggest that improved underwater hearing opened new evolutionary opportunities. Over millions of years, seals developed an impressive range of acoustic behaviours.

Today, some species produce haunting underwater vocalisations. Others can learn new sounds, keep a rhythmic beat and even imitate aspects of human speech. These unusual abilities may have become possible because their ancestors first evolved an ear capable of functioning effectively both above and below the water’s surface.

Life reconstruction of Enaliarctos mealsi.

Life reconstruction of Enaliarctos mealsi, one of the earliest marine seals from around 23 million years ago, being chased by a cetacean. It was capable of hearing both in-air and underwater (amphibious hearing), thanks to a specialised tissue in their ears (called a cavernous tissue). However, their hearing ranges in both environments were quite limited. Picture credit: Jaime Bran.

Picture credit: Jaime Bran

Museum Collections Unlock New Discoveries

The research depended upon the Natural History Museum’s extensive collections. Scientists examined more than two hundred specimens representing a hundred and nineteen living and extinct species of Carnivora.

By studying fossil skulls alongside modern seals, the researchers reconstructed the evolutionary history of the middle ear. This work demonstrates the continuing scientific value of museum collections assembled over many generations.

Dr Natalie Cooper, Merit Researcher at the London Natural History Museum, London stated:

“The Natural History Museum has some of the best seal collections in the world, and this study really shows its value. This research simply wouldn’t have been possible without these specimens,
which have been collected across hundreds of years from all over the world. It’s important that we know how seals hear because noise pollution in the ocean is growing. As the seas get louder, it’s harder for seals to find mates and communicate with each other putting their survival at risk. By understanding how these animals hear, we can start to put solutions in place.”

To read an article from 2020 but the discovery of a prehistoric pinniped in New Zealand that re-writes seal evolution: Sealing the Fate of Pinniped Evolution.

Understanding Hearing Function Can Help Protect Seals

The discovery has important conservation implications. Oceans are becoming increasingly noisy because of shipping, offshore construction and other human activities. Consequently, underwater noise can interfere with how seals communicate, locate mates and navigate.

Understanding seal underwater hearing provides researchers with valuable information about how these animals perceive their environment. In turn, this knowledge could help shape future conservation measures designed to reduce the impact of underwater noise pollution.

Mike from Everything Dinosaur commented:

“This fascinating study shows how fossils continue to answer important questions about the evolution of living animals. By combining evidence from extinct and modern seals, the researchers have explained one of the most remarkable hearing adaptations found in any mammal.”

Everything Dinosaur acknowledges the assistance of a media release from the London Natural History Museum in the compilation of this article.

The scientific paper: “The origin and evolution of amphibious hearing in pinnipeds” by James P. Rule, Travis Park, Moganavalli Kattan, Camille Grohé, Roxana Taszus, Stephanie M. Palmer, David P. Hocking, Justin W. Adams, Alistair R. Evans, Ian G. Brennan, Tahlia I. Pollock, Daniela Sanfelice, Felix G. Marx, Naoki Kohno, Martin Sabol, Alexander Stoessel, John J. Flynn and Natalie Cooper published in the Proceedings of the Royal Society B.

The award-winning Everything Dinosaur website: Models of Prehistoric Mammals.

15 07, 2026

Uragasaurus – A New Mamenchisaurid Sauropod from Thailand

By |2026-07-13T14:07:35+01:00July 15th, 2026|Categories: Palaeontological articles|2 Comments

A team of international researchers has named a remarkable new species of long-necked dinosaur from Thailand. Uragasaurus kalasinensis is the first formally described member of the Mamenchisauridae from Thailand. Although the fossil evidence consists of a single vertebra, the bone preserves a unique combination of anatomical features that enabled scientists to identify an entirely new dinosaur.  It is the fifteenth dinosaur to be named from fossils discovered in Thailand.

The research, published as an open-access paper in the journal “Scientific Reports”, highlights the growing importance of Thailand in helping palaeontologists understand the evolution and distribution of giant sauropod dinosaurs during the Late Jurassic.

Uragasaurus kalasinensis and the Mamenchisauridae

The newly described dinosaur lived approximately 145–150 million years ago during the Late Jurassic. Its fossil was recovered from the Phu Noi locality in Kalasin Province, north-eastern Thailand, within the Phu Kradung Formation.

Mamenchisaurids are famous for their extraordinarily long necks. Most known mamenchisaurids have been discovered in China, so the identification of Uragasaurus kalasinensis (pronounced You-rah-ga-sore-us cal-ah-sin-en-sis), considerably extends the confirmed geographical distribution of this distinctive group.

Scientists estimate that Uragasaurus measured around twenty metres in length and was a huge plant-eater that browsed vegetation growing high above the ground. Its neck has been described as being as long as a cricket pitch.

Uragasaurus kalasinensis life reconstruction.

A herd of Uragasaurus kalasinensis feeding in a Late Jurassic forest in Thailand. A metriacanthosaurid theropod can be seen in the background along with a pair of rhamphorhynchoid pterosaurs. Picture credit: Pakorn Chotchaiyaporn.

Picture credit: Pakorn Chotchaiyaporn. Licensed under a Creative Commons Attribution 4.0 International License.

A Single Vertebra Tells an Extraordinary Story

The fossil consists of an anterior dorsal vertebra. At first glance, naming a dinosaur from just one bone might seem surprising. However, vertebrae contain numerous anatomical characteristics that are extremely useful for identifying different dinosaur groups. Individual sauropod vertebrae often preserve unique anatomical characteristics that enable researchers to recognise and describe new species.

The researchers carefully compared the fossil with vertebrae belonging to many other Asian sauropods. They found a unique arrangement of bony ridges, cavities and supporting structures, known as laminae, which had not previously been documented in any recognised species. This distinctive combination of features justified the establishment of the new genus Uragasaurus.

Uragasaurus kalasinensis (PRC 460) vertebra.

The holotype anterior dorsal vertebra of Uragasaurus kalasinensis (PRC 460) in anterior (a) and posterior (b) views. Digital rendering of the specimen in anterior (c), posterior (d), right lateral (e), left lateral (f), dorsal (g), and ventral (h) views. Asterisk refers to an autapomorphic character. The blue highlight indicates the pneumatic fossa and pleurocoel. Picture credit: Nilpanapan et al.

Picture credit: Nilpanapan et al. Licensed under a Creative Commons Attribution 4.0 International License.

A Growing Picture of Thailand’s Dinosaur Fauna

Thailand has become increasingly important for dinosaur research over the last three decades. Numerous excavations have revealed an impressive diversity of prehistoric animals, including theropods, ornithopods and several species of sauropod.

To read an article from 2019 highlighting the discovery of two new theropod species from north-eastern Thailand: Two New Theropod Dinosaurs from Thailand.

The discovery of Uragasaurus kalasinensis demonstrates that north-eastern Thailand preserves fossils of dinosaur groups previously thought to be largely restricted to China. It also suggests that mamenchisaurids dispersed more widely across eastern Asia than palaeontologists had previously appreciated. The researchers propose that continued exploration of the Phu Kradung Formation is likely to reveal additional fossils that will help clarify the evolutionary history of these spectacular long-necked dinosaurs.

The giant Nagatitan chaiyaphumensis, the fourteenth dinosaur to be described from Thailand: The Last Titan from Thailand.

A Single Vertebra Can Rewrite Dinosaur History

While complete dinosaur skeletons understandably capture the public imagination, they are extremely rare. Discoveries such as Uragasaurus kalasinensis remind us that experienced palaeontologists can extract an enormous amount of scientific information from isolated bones. Careful anatomical comparisons often reveal evolutionary relationships that would otherwise remain hidden.

Uragasaurus kalasinensis anterior dorsal vertebra compared to the vertebrae of other mamenchisaurids.

A comparison of the anterior dorsal vertebrae of Uragasaurus kalasinensis with other Late Jurassic mamenchisaurids. Mamenchisaurus youngi (Upper Shaximiao Formation of Sichuan, China) and Mamenchisaurus hochuanensis (Upper Shaximiao Formation of the Chongqing municipality, China). Abbreviations lprdl, lower prezygodiapophyseal lamina; uprdl, upper prezygodiapophyseal lamina. Other abbreviations can be found in the second image in this article.  Asterisk refers to an autapomorphic character. The blue highlight indicates the pneumatic fossa and pleurocoel. Note images are not to scale. Picture credit: Nilpanapan et al.

Picture credit: Nilpanapan et al. Licensed under a Creative Commons Attribution 4.0 International License.

A Significant Discovery

The description of Uragasaurus kalasinensis represents another important milestone for Southeast Asian palaeontology. The discovery strengthens evidence that Thailand preserves an exceptionally important record of Jurassic dinosaurs and demonstrates that many new species remain to be discovered.

As fieldwork continues across the region, further fossil discoveries are likely to improve our understanding of how giant sauropods evolved and dispersed across Asia during the Jurassic.

Commenting on the research, Mike from Everything Dinosaur said:

“This fascinating study demonstrates how even a single fossil bone can significantly improve our understanding of dinosaur evolution. Thailand continues to produce scientifically important discoveries, and Uragasaurus kalasinensis adds another impressive dinosaur to the country’s growing fossil record.”

The scientific paper: “A new mamenchisaurid sauropod from the Lower Phu Kradung Formation, Upper Jurassic of northeastern Thailand” by Apirut Nilpanapan, Sita Manitkoon, Varavudh Suteethorn and Komsorn Lauprasert an open-access paper published in Scientific Reports.

12 07, 2026

New Study Examines Tyrannosaur Reproduction Strategy

By |2026-07-09T10:44:28+01:00July 12th, 2026|Categories: Palaeontological articles|0 Comments

A new study examining Tyrannosaurus rex hatchlings has provided fresh insight into the early lives of these famous theropod dinosaurs. Researchers writing in the journal “Biology” investigated evidence linked to the development and reproductive strategies of large meat-eating dinosaurs.  The researchers concluded that tyrannosaurs produced relatively small hatchlings compared to modern birds. This suggests that they laid large numbers of eggs and invested less energy in caring for their young.

Although adult Tyrannosaurus rex specimens are amongst the most famous fossils ever found, the earliest growth stages remain poorly understood. Fossils of very young tyrannosaurs are exceptionally rare. Therefore, palaeontologists continue to search for clues about how these remarkable animals developed.

Tristan the Tyrannosaurus rex skull.

The beautiful Tristan the Tyrannosaurus rex skull shown in lateral view. A new study suggests different niches in the ecosystem for juvenile tyrannosaurs compared to the adult animals. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Studying Tyrannosaurus rex Hatchlings

The enormous size of adult T. rex raises fascinating questions about reproduction. Every giant dinosaur began life as a small hatchling.  All dinosaurs emerged from eggs. Consequently, scientists want to understand how these animals grew from vulnerable juveniles into apex predators.

The scientists, which included researchers from the University of Bath, examined fossil evidence and compared growth patterns seen in related dinosaurs. This work helps palaeontologists build a more complete picture of tyrannosaur biology. Dinosaurs occupied an evolutionary position between more primitive reptiles and modern birds, both in their anatomy and in some aspects of their biology such as reproduction strategies.

Young tyrannosaurs would have looked very different from adults. They were probably lightly built, long-legged animals adapted for speed. In contrast, mature T. rex individuals developed huge skulls, powerful jaws and immense bite forces.

This dramatic transformation demonstrates how dinosaurs could occupy different ecological roles during their lives.

New study into Tyrannosaurus rex hatchlings.

Tyrannosaur hatchlings had very different body proportions compared to adults. A new study provides fresh insights into tyrannosaur reproduction strategies. Picture credit: Everything Dinosaur (AI Assisted).

Picture credit: Everything Dinosaur (AI Assisted)

Understanding Dinosaur Growth and Reproduction

The study also highlights the challenges associated with investigating dinosaur reproduction. Unlike modern birds and reptiles, palaeontologists cannot directly observe extinct dinosaurs nesting or raising their young.

Instead, scientists rely on fossils, bone histology, eggs, embryos and comparisons with related, extant animals. Dinosaur reproductive strategies probably represented an intermediate stage between more primitive reptiles, such as crocodilians which typically provide limited parental care, and modern birds. Birds often demonstrate advanced parental behaviours and significant investment in their offspring.

Evidence from other theropod dinosaurs shows that many species grew rapidly. This fast growth helped them reach larger sizes more quickly and may have reduced the risks faced by young animals.

From Tiny Hatchling to Apex Predator

An adult Tyrannosaurus rex could reach more than twelve metres in length. However, newly hatched individuals would have been tiny compared to their parents. The research team studied bones and teeth of hatchlings from the Frenchman Formation of Saskatchewan (Canada). These fossils reputedly represent T. rex. In addition, juvenile tyrannosaur fossils from the geologically older Dinosaur Provincial Park formation were studied. These fossils have been assigned to Gorgosaurus.

The difference between hatchlings and adults suggests that young tyrannosaurs may have hunted different prey. This reduced competition between generations and allowed animals of different ages to exploit separate ecological niches. Indeed, the contrasting body shapes between juvenile and mature tyrannosaurs fuelled the Nanotyrannus debate.  However, recent studies have concluded that lightly built, long-legged tyrannosaurs thought to represent T. rex juveniles are most likely a different tyrannosaur taxon.

To read more about the recent Nanotyrannus research: New Paper Reinforces Nanotyrannus Unique Taxon Theory.

This idea, animals of the same species filling different niches depending on their age is known as ontogenetic niche partitioning, has been proposed for several dinosaur groups.

Revealing the Early Lives of Famous Dinosaurs

The study of Tyrannosaurus rex hatchlings remains an exciting area of palaeontology. For example, in this paper, the researchers stated that synchrotron scans revealed Haversian bone re-modelling, suggesting that tyrannosaurs moved soon after hatching.  It is speculated that tyrannosaurs may have been precocial.  Precocial young are relatively mobile and independent soon after hatching.

A 2021 article that highlights a study suggesting that baby tyrannosaurs were precocial: Tyrannosaurs – Born Ready to Hunt!

Future fossil discoveries may reveal more information about nesting behaviour, growth rates and juvenile anatomy.

Everything Dinosaur team members regularly highlight that even the most famous dinosaurs continue to surprise scientists. New research techniques and fossil discoveries are helping experts build a clearer picture of how these extraordinary animals lived. Understanding the youngest members of this species provides valuable information about one of the most remarkable predators in Earth’s history.

A dinosaur egg fossil.

A dinosaur egg (believed to be from a theropod dinosaur). Theropod dinosaur eggs tend to be elongated and less round compared to the eggs of other dinosaurs such as sauropods. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Estimating Nest Sizes

Clutch sizes were likely large. The team conservatively estimated that a small, female adult T. rex would lay around twenty eggs. The largest T. rex females could perhaps lay thirty eggs. In comparison, Gorgosaurus (G. libratus), may have laid more eggs per clutch. For example, the researchers propose clutch sizes of up to a hundred eggs for Gorgosaurus.

Scientists can only speculate about the mortality rate of hatchling tyrannosaurs. However, animals that produce large numbers of offspring typically experience high juvenile mortality rates. Many predators could have killed a baby T. rex. For example, hatchlings had to avoid dromaeosaurs, crocodilians and the powerful beaks of azhdarchid pterosaurs.

The scientific paper “Hatchlings of Tyrannosaurus rex and the Evolution of Dinosaur Reproductive Strategies” by Nicholas R. Longrich, Peter J. Makovicky, Tim Tokaryk, David M. L. Cooper, Evan T. Saitta, Gregory M. Erickson, Tamas Szekely and Eric Snively published in Biology.

The Everything Dinosaur website: Models of Theropods and Other Dinosaurs.

9 07, 2026

Examining the Remarkable Australian Marsupial Lion – A Super Predator from Down Under

By |2026-07-08T10:36:28+01:00July 9th, 2026|Categories: Palaeontological articles|0 Comments

The study of Thylacoleo carnifex anatomy has revealed one of the most unusual mammalian predators known to science. Often called the “marsupial lion”, this apex predator was not a member of the cat family.  Indeed, its closest living relatives are wombats and koalas. Despite evolving from primarily plant-eating ancestors, Thylacoleo carnifex became a highly specialised carnivore. Its powerful jaws, extraordinary teeth and muscular body made it a significant predator of the Pleistocene Epoch.  Early studies suggested that it may have been frugivore (fruit eater), or that it was a scavenger.  However, more modern interpretations depict Thylacoleo carnifex as a hypercarnivore.

Understanding Thylacoleo carnifex Anatomy

The first fossils of Thylacoleo carnifex were scientifically described in the 19th century. Since then, more complete fossil discoveries have transformed our understanding of this animal. Older reconstructions often depicted Thylacoleo as cat-like. However, detailed studies show that this marsupial had a very different body plan. It combined tremendous strength with adaptations for climbing, gripping and ambushing prey.

A large individual may have measured around 1.5 metres long. Many adults probably weighed between 100 and 130 kilograms, although exceptionally large specimens may have approached 160 kilograms. Larger individuals may represent males, suggesting possible sexual dimorphism. After all, sexual dimorphism is seen in extant relatives of this species.

This extinct marsupial continues to inspire scientists and palaeoartists.  For instance, it has featured on the front cover of the prestigious “Prehistoric Times” magazine.

Thylacoleo carnifex anatomy.

The front cover features a Marsupial lion. Thylacoleo carnifex features on the front cover art of “Prehistoric Times” magazine issue 85. Picture credit: Mike Fredericks.

Picture credit: Mike Fredericks

A Powerful Skull and an Incredible Bite

The skull of Thylacoleo carnifex was short, broad and extremely robust. Huge jaw muscles helped generate a tremendous bite force. Indeed, studies suggest that relative to body size, Thylacoleo possessed one of the most powerful bites of any known mammalian predator. The eyes faced forwards, providing binocular vision. This adaptation would have helped with judging distance when attacking prey. Consequently, palaeontologists often interpret Thylacoleo as an ambush hunter rather than a pursuit predator.

The Remarkable Teeth of Thylacoleo carnifex

One of the most fascinating aspects of Thylacoleo carnifex anatomy is the dentition. Unlike felids, Thylacoleo did not rely on large canine teeth to despatch prey. Its upper canines were small and rounded, whilst the lower jaw lacked canine teeth entirely.

The dental formula of T. carnifex:

  • Upper jaw (each side): 3 incisors, 1 canine, 3 premolars and 1 molar
  • Lower jaw (each side): 1 incisor, no canines, 3 premolars and 2 molars.

The lower incisors were enlarged, chisel-shaped and projected forwards.  In addition, fossils show extensive wear. The enormous third premolars were highly specialised. They acted like shears and were functionally similar to the carnassial teeth found in modern carnivorous mammals.

No living predator has a set of teeth quite like Thylacoleo carnifex.

To read an article about the discovery of an ancestor of the “marsupial lion”: Attenborough’s New Kitty.

Strong Forelimbs and a Deadly Thumb Claw

The forelimbs of Thylacoleo were exceptionally powerful. The shoulders and front legs were heavily muscled, suggesting an animal that relied on strength to subdue prey. Furthermore, the manus (hand) had five digits, each equipped with a claw. The first digit, equivalent to a thumb, was particularly remarkable. It was semi-opposable and carried a large, strongly curved claw.

This enlarged claw was probably used to grip prey and assist with climbing. It may have been protected when not in use, although it worked differently from the retractable claws of modern cats.

A Marsupial Built for Power Not for Speed

The body of Thylacoleo carnifex was compact and muscular. It had a deep chest, broad shoulders and a relatively short back. Its body proportions suggest that this predator was not built for chasing prey over long distances. Instead, it was adapted for explosive power, climbing ability and controlling struggling animals. The hind feet provide further evidence that Thylacoleo was no cat-like predator. It walked with the sole of the foot contacting the ground, a posture known as plantigrade locomotion. Bears and humans also use this type of stance.

The potential maximum velocity of Thylacoleo remains unknown.  The combat bodies of extant wombats (see image below) share many characteristics with their close relatives (Thylacoleonidae).  At first sight, these animals might look like they are incapable of running at speed.  However, appearances can be deceptive.  Wombats have been recorded running at twenty-five miles per hour (forty kilometres per hour) over short distances.

Like other diprotodontian marsupials, the second and third toes were probably fused together.

A stuffed specimen of a wombat on display.

Thylacoleo is classified as a member of the Diprotodontia suborder the Vombatiformes. Extant wombats such as this forest wombat (Vombatidae family) are closely related to marsupial lions (Thylacoleonidae).

Picture credit: Everything Dinosaur

The Tail of Thylacoleo carnifex

For many years, the tail of Thylacoleo was poorly understood. However, more complete fossil discoveries have revealed that this predator had a long and muscular tail.

The tail may have provided extra support when the animal reared upwards. This “tripod” posture is seen in some living marsupials.

Some Australian rock art has been suggested to represent Thylacoleo. These interpretations remain debated, but they raise interesting questions about the external appearance of this extinct animal. For example, there could have been a tuft on the end of the tail.

Did Thylacoleo carnifex Hunt Diprotodon?

Thylacoleo carnifex shared its environment with many famous Australian megafauna species, including the giant marsupial Diprotodon optatum. Diprotodon was the largest marsupial known to science. A fully-grown male Diprotodon had a shoulder height of approximately 1.8 metres.  It weighed around three tonnes, around twenty-five times heavier than Thylacoleo.

However, Thylacoleo may have targeted young, injured or vulnerable individuals. Its powerful forelimbs, gripping claws and devastating bite would have made it a dangerous predator.  The CollectA Deluxe Diprotodon, introduced in 2024 shows some remarkable detail.  For example, the top of the left hind limb reveals an old scar from an attack from a Thylacoleo. The scars are old suggesting an attack when this Diprotodon was much younger.

Whilst speculative, it is interesting to note that CollectA added this detail, a speculation on a predator/prey relationship.

CollectA Deluxe Diprotodon model.

The CollectA Diprotodon model has an old scar from a marsupial lion on its rump.

The relationship between these two iconic marsupials highlights the complexity of prehistoric Australian ecosystems.

To view the CollectA Deluxe model range: CollectA Deluxe Age of Dinosaurs.

Thylacoleo carnifex Anatomy Reveals A Unique Australian Predator

Research into Thylacoleo carnifex anatomy continues to demonstrate how unusual this animal was. It was not simply Australia’s version of a big cat. Instead, evolution produced a completely different type of predator. Indeed, several species have been classified, tracing the origins of these bizarre carnivores back into the Oligocene Epoch.

To read a blog post outlining ideas into Thylacoleo hunting strategy: How the Marsupial Lion Got to Grips with its Prey.

Mike from Everything Dinosaur commented:

“With its powerful front limbs, extraordinary teeth and specialised hunting adaptations, Thylacoleo remains one of the most fascinating mammals to have ever lived.  Thylacoleo carnifex died out around 40,000 years ago.  Modern humans would have encountered it.  Imagine viewing a living Thylacoleo!  I am sure this creature would have had a special status amongst those hunter gatherers that shared its environment.”

The award-winning Everything Dinosaur website: Dinosaur Toys and Prehistoric Animal Models.

29 06, 2026

Scientists Formally Describe the First Dinosaur Fossil Found in Antarctica

By |2026-06-30T06:38:08+01:00June 29th, 2026|Categories: Palaeontological articles|0 Comments

Scientists have formally described the first dinosaur fossil found in Antarctica. The remarkable discovery is a single vertebra from a Late Cretaceous titanosaur. Although the fossil was collected more than forty years ago, researchers have only recently confirmed its identity.  The first dinosaur fossil found in Antarctica described in the journal Acta Palaeontologica Polonica.

The Late Cretaceous Antarctic titanosaur life reconstruction.

A life reconstruction of the titanosaur. The single caudal vertebra may have come from a dwarf titanosaur species or perhaps a titanosaur that was not fully grown. Picture credit: Andrew McAfee, Carnegie Museum of Natural History.

Picture credit: Andrew McAfee, Carnegie Museum of Natural History

The First Dinosaur Fossil Found in Antarctica Described

The fossil was discovered in 1985 by British Antarctic Survey geologist Dr Mike Thomson during an expedition Ross Island. At the time, the team focused on finding marine fossils such as ammonites. These fossils help scientists date ancient rock layers. However, one unusual bone collected during the expedition has now proved to be Antarctica’s first recognised dinosaur fossil.

The survey team's camp during the 1985 expedition to James Ross Island (Antarctica).

A photograph of the geology field camp on James Ross Island taken in 1985. Picture credit: Mike Thomson (British Antarctic Survey).

Picture credit: Mike Thomson (British Antarctic Survey)

Researchers identified the specimen as a tail vertebra from a titanosaur. Titanosaurs belonged to a diverse and geographically widespread group of sauropod dinosaurs. These plant-eating giants had long necks, long tails and pillar-like limbs. Some species ranked among the largest land animals ever to walk the Earth. The Antarctic animal, however, measured only around six to seven metres long. It was either a juvenile, or it possibly represented a relatively small species.

The Santa Marta Formation

The fossil came from the Santa Marta Formation, a sequence of Late Cretaceous rocks dating to approximately 82 million years ago (Campanian faunal stage). At that time, Antarctica looked very different. Instead of being buried beneath thick ice, much of the continent supported lush temperate forests. Dinosaurs, alongside a wide variety of other animals and plants, thrived in this much warmer environment.

Antarctic titanosaur caudal vertebra.

Eutitanosauria indet. (BAS D.8621.25) from the Upper Cretaceous (lower Campanian) Beta Member (≈ upper Lachman Crags Member) of the Santa Marta Formation of James Ross Island, Antarctica. Fossil is shown in anterior view. Picture credit: The Trustees of the Natural History Museum, London.

Picture credit: The Trustees of the Natural History Museum, London

Interestingly, the vertebra was preserved in marine sediments. Scientists think the dinosaur died on land before its body drifted out to sea. Eventually, the remains settled onto the seabed where they became buried and fossilised.

Commenting on the significance of this single fossil bone, Dr Mark Evans (British Antarctic Survey) stated:

“This fossil was found by Dr Mike Thomson, one of the true pioneers of Antarctic geology, whose work helps us date all fossil finds across the Antarctic Peninsula today. When I first spotted this bone in our collections a few years ago, I suspected it was a dinosaur. After looking at it properly, I thought it was probably a titanosaur tail vertebra. Looking back at Mike’s notebooks, he knew it was a large reptile – so it’s very special to confirm his find forty years later. We’ve also been able to compare it against dinosaur fossils that have been found since.”

Antarctica preserves very few dinosaur fossils. Today, almost the entire continent lies beneath a vast ice sheet. As a result, very little fossil-bearing rock remains exposed. Most discoveries come from isolated coastal outcrops and mountain ranges where ancient rocks reach the surface. Consequently, every new specimen provides valuable information about Antarctica’s prehistoric ecosystems.

The titanosaur caudal vertebra shown in posterior view.

First ever dinosaur remains found in Antarctica described. A photograph of the single, caudal vertebra (BAS D.8621.25) shown in posterior view. Picture credit: The Trustees of the Natural History Museum, London.

Picture credit: The Trustees of the Natural History Museum, London

By comparing the vertebra with more recently discovered sauropod fossils, researchers confirmed that the bone belonged to a titanosaur.

An Important Milestone in Antarctic Exploration

Professor Paul Barrett of the Natural History Museum explained that the fossil represents an important milestone in Antarctic exploration. Furthermore, he suggested that many more dinosaur discoveries could await scientists as additional fossil-bearing rocks become exposed.

This discovery also improves our understanding of dinosaur evolution across the southern continents. During the Late Cretaceous, Antarctica formed part of the southern supercontinent Gondwana. Land connections linked Antarctica with South America and Australasia. Therefore, fossils such as this provide important evidence for the movement and distribution of dinosaurs across these ancient landmasses.

The first dinosaur fossil found in Antarctica may consist of only a single vertebra. Nevertheless, it represents a landmark discovery. Moreover, it highlights how museum collections continue to yield important scientific discoveries decades after fossils were first collected.

Everything Dinosaur acknowledges the assistance of a media release from the London Natural History Museum in the compilation of this article.

The scientific paper: “A titanosaurian sauropod dinosaur from the Upper Cretaceous of Antarctica” by Paul M. Barrett, Philip D. Mannion, Samantha L. Beeston, Matthew C. Lamanna, Brett Clark, Alejandro Otero, José P. O’gorman and Mark Evans published in Acta Palaeontologica Polonica.

For museum quality models of titanosaurs and other sauropods: Dinosaur and Prehistoric Animal Models.

19 06, 2026

Pterosaurs May Have Possessed Iridescent Pycnofibres

By |2026-06-21T12:34:59+01:00June 19th, 2026|Categories: Palaeontological articles|0 Comments

New research suggests that colourful tapejarid pterosaurs may have been even more spectacular than previously imagined. A recently published study proposes that some of these flying reptiles possessed iridescent pycnofibres that produced shimmering colours. As a result, these structures may have played an important role in visual signalling and display.

The bodies of pterosaurs, the first vertebrates to achieve powered flight, are covered with integumentary filaments (pycnofibres). They are thought to be homologous with feathers associated with the Dinosauria.

CollectA Deluxe Caiuajara with moveable jaw.

The Age of Dinosaurs Deluxe Caiuajara pterosaur figure with a moveable jaw. Tapejarid pterosaurs like Caiuajara have been depicted with colourful crests, however, a recent study (May 2026) proposes that the pycnofibres covering their bodies may have been iridescent.

The image (above) shows the CollectA Supreme Deluxe Caiuajara figure.  It is pronounced – Kay-you-ah-jar-rah.  CollectA have introduced an extensive range of beautiful pterosaur scale models.

To view the CollectA Deluxe model range: Scale Models of Pterosaurs and Other Prehistoric Animals.

Colourful Tapejarid Pterosaurs

The Tapejaridae were a geographically widespread Early Cretaceous pterosaur family with probable Asian origins.  Tapejarid fossil material is known from the UK, Europe, Africa, South America and possibly from North America too.  All known tapejarids were edentulous (lacked teeth). These pterosaurs are famed for their large and flamboyant crests.  A recently published paper suggests that pycnofibres covering their bodies may have been capable of iridescence.  If this is the case, they would have been extremely colourful.

To read a blog post from 2020 about the discovery of a tapejarid pterosaur in the Wessex Formation (Wightia declivirostris)A Terrific Tapejarid from the Isle of Wight.

Significantly, the recently published paper reveals evidence of something remarkable.

Scientists identified a layered arrangement of melanosomes within the pycnofibres of a tapejarid specimen. The fossil material represents Sinopterus dongi from the Early Cretaceous Jehol Biota.  It had not been formally studied previously. Importantly, this internal structure of melanosomes resembles the organisation seen in the iridescent feathers of living birds. In modern species, such arrangements generate structural colours that can shift and shimmer when viewed from different angles. Consequently, the researchers propose that these pterosaurs exhibited colours ranging from green to magenta.

Did Iridescence Appear Early in the Evolution of Integumentary Filaments?

The research also has wider implications. According to the authors, this discovery indicates that the capacity for producing iridescence evolved very early in the evolution of integumentary filaments. Therefore, complex colour signalling and visual displays may have originated long before the appearance of birds.

In addition, the research provides further evidence that pycnofibres were multifunctional. Although they probably helped with insulation and thermoregulation, they also appear to have been used for communication and display. This finding supports the idea that visual signalling played a significant role in pterosaur behaviour. After all, if you are a tapejarid with a bold crest, then why not have iridescent pycnofibres too?  The Early Cretaceous skies could have been filled with colourful tapejarid pterosaurs.

Highlighting the importance of this recent research, Mike from Everything Dinosaur commented:

“Large head crests already made tapejarids some of the most distinctive pterosaurs known. Now, scientists suggest that these reptiles may have enhanced their appearance with dazzling colours. Such displays could have helped attract mates, establish dominance or identify members of the same species.”

Implications for Palaeoartists and Model Makers

Most pterosaurs very probably had excellent colour vision.  Using colour for signalling, social status and display makes sense.  This has implications for model makers and palaeoartists. As a result of this study, colourful tapejarid pterosaurs may have looked far more vibrant than traditionally portrayed. They might have rivalled many modern birds in both appearance and visual complexity.

Wild Safari Prehistoric World Tapejara model.

A model of Tapejara imperator (Safari Ltd)

The image (above) shows a model of a tapejarid pterosaur (Tapejara imperator).  Most models have bright crests, but the pycnofibres tend to be plain in comparison. The conclusions from this study suggest a re-think when it comes to pterosaur colouration.

The paper highlights how exceptionally preserved fossils continue to transform our understanding of prehistoric life. Moreover, it demonstrates that the skies of the Cretaceous Period may have been filled with flying reptiles adorned with brilliant, iridescent colours.

The scientific paper: “Iridescence in pterosaur pycnofibers and the evolution of integumentary coloration” by Zelin Wu, Liliana D’ Alba, Chang-Fu Zhou, Julia A. Clarke, Jinhua Li, Matthew D. Shawkey and Quanguo Li published in bioRxiv.

The award-winning Everything Dinosaur website: Models of Pterosaurs and Other Prehistoric Animals.

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