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.

22 01, 2026

New Research Postulates Giant, Prehistoric Kangaroos Could Still Hop

By |2026-01-22T07:30:00+00:00January 22nd, 2026|Categories: Palaeontological articles|0 Comments

Researchers studying the fossilised remains of giant, prehistoric kangaroos have concluded that even marsupials weighing more than two hundred kilograms were not too big to hop. This new study, published in the academic journal “Scientific Reports” challenges the long-held view that these giants were walkers rather than hoppers. The research team examined fossils of short-faced kangaroos (Sthenurinae). During the Pleistocene some of these kangaroos evolved giant, robust forms. Their method of locomotion remains controversial. Did humans encounter walking giant short-faced kangaroos or did they witness a sthenurine hopping?

Cast of the skelton of Sthenurus occidentalis. Was this a hopping stenurine?

Cast of a sthenurine skeleton (Sthenurus occidentalis) in the South Australian Museum. Picture credit Megan Jones.

Picture credit: Megan Jones

A Sthenurine Hopping Hypothesis

The Sthenurinae are a subfamily of the Macropodidae. The Macropodidae is a large family of marsupials that includes kangaroos, wallabies and their relatives. The largest extant kangaroo is the red kangaroo (Osphranter rufus). Males can weigh as much as ninety kilograms and stand 1.6 metres tall. They are the largest terrestrial mammal native to Australia and the largest living marsupial. However, during the Pleistocene, much larger kangaroos evolved.  For example, whilst small, wallaby-sized sthenurines are known, other taxa were much larger than living kangaroos. The sthenurine Procoptodon goliah is thought to be the biggest kangaroo that ever existed.  Males stood around two metres tall and weighed perhaps as much as two hundred and forty kilograms.

Life reconstruction of a sthenurine hopping.

Reconstruction of a giant short-faced kangaroo (sthenurine) hopping. Picture credit: Megan Jones.

Picture credit: Megan Jones

Earlier studies suggested that hopping would become mechanically impossible above a body weight of a hundred and fifty kilograms. Those conclusions were largely based on studies of extant kangaroo skeletons.  The anatomy of modern kangaroos was simply scaled up.

To read a blog post from 2014 that looked at evidence for walking locomotion in largest members of the Sthenurinae: Giant Kangaroos Made for Walking.

This new study involved scientists from The University of Manchester, in collaboration with the University of Bristol and the University of Melbourne.  These researchers took a different approach.  Measurements taken from the skeletons of extant species were compared with the fossil remains of extinct species.  The researchers conclude that giant kangaroos may have been capable of hopping.  Indeed, early Australians could have observed a sthenurine hopping.

Lead Researcher Megan Jones, (The University of Manchester) explained:

“Previous estimates were based on simply scaling up modern kangaroos, which may mean we miss crucial anatomical differences. Our findings show that these animals weren’t just larger versions of today’s kangaroos, they were built differently, in ways that helped them manage their enormous size.”

Examining the Two Limiting Factors for Hopping

The research team examined two potential limiting factors for hopping, the strength of the foot bones and the ability of the ankle to anchor the powerful tendons that power hopping.  The analysis demonstrated that giant, short-faced kangaroos had shorter, robust foot bones capable of withstanding landing forces and their heel bones were broad enough to support much thicker tendons.

However, Pleistocene giant kangaroos probably did not bounce across the landscape like modern red kangaroos.

Co-author Dr Katrina Jones (Bristol University), stated:

“Thicker tendons are safer, but they store less elastic energy. This likely made giant kangaroos slower and less efficient hoppers, better suited to short bursts of movement rather than long-distance travel. But hopping does not have to be extremely energy efficient to be useful, these animals probably used their hopping ability to cross rough ground quickly or to escape danger.”

Giant short-faced kangaroo heel bone.

Heel bone (calcaneum) of the largest kangaroo species, Procoptodon goliah. P. goliah stood over two metres tall and had an estimated body mass of 240 kilograms, almost three times the size of the largest living kangaroos. Picture credit: Megan Jones/UCMP.

Picture credit: Megan Jones/UCMP

A Range of Locomotion Strategies Identified

The fossil analysis also reveals a range of locomotion strategies adopted by extinct kangaroos.  Some giants may have mixed hopping with other forms of movement, including bipedal walking and moving around on all fours.  Sthenurine hopping may have just been one part of a broader “movement repertoire”.  The research implies different ecological niches for prehistoric kangaroos.

Fellow researcher and co-author Dr Robert Nudds, Senior Lecturer in Evolution, Infection and Genomics at The University of Manchester commented:

“Our findings contribute to the notion that kangaroos had a broader ecological diversity in prehistoric Australia than we find today, with some large species grazers like modern kangaroos while others were browsers – an ecological niche not seen in today’s large kangaroos.”

The research provides the most comprehensive assessment to date of the mechanical feasibility of hopping in giant extinct kangaroos.

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

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

15 01, 2026

New Study Suggests T. rex Grew Up More Slowly Than Previously Thought

By |2026-01-18T18:09:15+00:00January 15th, 2026|Categories: Palaeontological articles|Tags: , , , |0 Comments

A comprehensive overview of T. rex ontogeny has been published in the open access journal PeerJ.  This research suggests that Tyrannosaurus rex could have taken around forty years to reach full size. The study suggests that the Tyrannosaurus rex species grew more gradually and over a longer lifespan than indicated by prior models, with a protracted period of subadult development.  Knowing more about the ontogeny (growth) of dinosaurs like T. rex will help scientists to better understand how this iconic predator may have lived and how it interacted with prey species.  In addition, this research has implications with regards to the current debate over the Nanotyrannus taxon.

Previous studies had indicated that Tyrannosaurus rex grew rapidly and that it had a series of dramatic growth spurts before reaching adult size at around twenty-five years of age. In 2015, the reboot of the “Jurassic Park” franchise occurred. In the film “Jurassic World” a new theropod dinosaur was introduced – Indominus rex. We wrote an article comparing the growth rate of T. rex with this new, fictional theropod. We compared the growth rates proposed for these two theropod taxa. Whilst speculative, it permitted a comparison of I. rex growth based on the fictional movie timeline with the postulated growth rate for a large tyrannosaurid based on the current research.  The results are shown in the graph below.

T. rex ontogeny compared to I. rex.

I. rex versus T. rex growth rates.  The timeline from the 2015 film “Jurassic World” hinted at an extremely rapid growth rate for the fictional theropod Indominex rex.  At the time, research suggested that T. rex grew rapidly too, undergoing a series of growth spurts, particularly in its teenage years before reaching full size at around twenty-five years of age.  New research suggests T. rex grew more slowly.  Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The article comparing the growth rates of Tyrannosaurus rex and Indominus rexThe Growth Spurts of Tyrannosaurs.

A Comprehensive Assessment of T. rex Ontogeny

Earlier studies into T. rex ontogeny proposed that the “Tyrant Lizard King” exceeded eight tonnes in weight within two decades and had a lifespan of approximately thirty years. However, this understanding of Tyrannosaurus rex growth dynamics is dependent on single-point histological sampling of multiple skeletal elements and lacks specimens encompassing the earliest growth states.

Corresponding author of the study Dr Holly Ballard (Oklahoma State University), specialises in studying osteohistology (growth patterns of animals preserved in bone tissue) to map population growth dynamics in extinct vertebrates. We have reported on Holly’s research previously.  For example, back in 2015, we wrote an article examining research into the growth rates of the dinosaur Maiasaura peeblesorum.

To read this blog post: Examining the Lives of Dinosaurs.

Studying the Leg Bones from Seventeen Individuals

The researchers examined the growth rings preserved in the leg bones of seventeen T. rex. The individuals ranged from juveniles to mature adults.  It is the most comprehensive histological analysis of Tyrannosaurus ontogeny to date. Four alternative statistical models were employed.  The study indicates that rather than racing to adulthood with remarkable growth spurts, Tyrannosaurus rex grew more slowly and steadily than previously thought.

Co-author of the study John “Jack” Horner (Chapman University, California) explained that a forty-year growth phase may have permitted younger tyrannosaurs to fill a variety of ecological niches within Late Cretaceous palaeoenvironments.  Their growth rate could be one factor that permitted this taxon to dominate terrestrial ecosystems as the apex predator.

Many Tyrannosaurus rex models and figures are based on monsters from the movies.  Only a few T. rex models are developed based on closely following the scientific evidence. Our own Everything Dinosaur Evolution 1:33 scale Tyrannosaurus rex figure follows the fossil record closely.  The model represents a mature, adult animal.  Rather than reaching full size at around twenty-five years of age, based on this research, our figure represents a T. rex more than thirty years of age.

According to this study, T. rex could have reached forty years of age. However, very few individuals lived that long. Indeed, only two specimens in the sample of seventeen tyrannosaurs represent adult dinosaurs.

Introducing Everything Dinosaur Evolution.

Introducing Everything Dinosaur Evolution. A stunning range of prehistoric animal models developed by following the fossil evidence. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

To view the Everything Dinosaur Evolution range: Everything Dinosaur Evolution Tyrannosaur Figures.

The Implications for Nanotyrannus

Although Tyrannosaurus rex is the best-known species of this group of dinosaurs, recent studies have proposed that some specimens previously identified as T. rex may in fact be members of other related species. Some scientists, for example, have argued that certain smaller specimens represent a small-bodied species, named Nanotyrannus, rather than juvenile specimens of Tyrannosaurus rex.

The paper’s authors acknowledge the variation in tyrannosaurs. No single, completely uniform growth pattern is highlighted. They acknowledge variation among individual specimens, including ones historically attributed to the Nanotyrannus genus. However, T. rex ontogeny alone cannot prove that the outlying specimens within this dataset represent different taxa. Unusual growth patterns might reflect individual variation or pathology.  In addition, the dataset of tyrannosaur specimens is far from complete.  To gain greater certainty, a much larger sample would be required.

To read Everything Dinosaur’s blog post from November 2024 featuring details of the paper validating the Nanotyrannus taxon: A New Chapter in Tyrannosaur Evolution.

This new study does challenge current views on T. rex ontogeny.  These researchers conclude that the Tyrannosaurus rex species grew more gradually and over a longer lifespan.  Few tyrannosaur population members attained their adult size. Furthermore, this research indicates that these predators had a prolonged subadult phase of their lifecycle.

The scientific paper: “Prolonged growth and extended subadult development in the Tyrannosaurus rex species complex revealed by expanded histological sampling and statistical modeling” by Woodward, Myhrvold and Horner published in PeerJ.

The multi-award-winning Everything Dinosaur website: Tyrannosaur and Other Prehistoric Animal Figures.

14 01, 2026

A New Saurolophine Hadrosaur is Scientifically Described

By |2026-01-16T14:32:37+00:00January 14th, 2026|Categories: Palaeontological articles|Tags: , , |0 Comments

Catching up with some of the latest developments in ornithischian dinosaur research. For example, late last year, a new saurolophine hadrosaurid dinosaur from New Mexico was formally described.  Named Ahshislesaurus wimani, it reinforces the view that hadrosaurs were among the dominant large herbivorous dinosaurs present in southern Laramidia during the last ten million years of the Cretaceous.

Ahshislesaurus wimani life reconstruction.

Ahshislesaurus wimani life reconstruction. Picture credit: Sergey Krasovskiy.

Picture credit: Sergey Krasovskiy

Ahshislesaurus wimani

The research team erected a new hadrosaur taxon based on the study of skull bones as well as postcranial material. The bones that would be identified as Ahshislesaurus were uncovered in San Juan County (northwestern New Mexico), by famed collector John B. Reeside, Jr. in 1916. In 1935, the fossils were classified as belonging to another hadrosaurid named Kritosaurus navajovius. However, this new research identified distinctions between these fossils and all known hadrosaurids, including several key differences in the animal’s skull.

Ahshislesaurus (pronounced Ah-shi-sle-sore-us), is estimated to have reached lengths in excess of eleven metres.  It might have weighed more than eight tonnes. The fossil material comes from the lower Hunter Wash Member of the lower Kirtland Formation (Campanian faunal stage). The paper describing the new species was published in the Bulletin of the New Mexico Museum of Natural History and Science.  It is a journal managed by the New Mexico Museum of Natural History and Science.

Co-author of the paper, Dr Anthony Fiorillo, Executive Director of the New Mexico Museum of Natural History and Science stated:

“Discoveries like this remind us that science truly is a community. Our team of researchers spanning five institutions and two countries were able to build upon research that started nearly a century ago and now advances our understanding of what our state looked like during the Late Cretaceous Period.”

Views of the right jugal of the holotype of Ahshislesaurus wimani.

Right jugal of the holotype of Ahshislesaurus wimani gen. et sp. nov., (USNM VP-8629); in A, lateral view; B, medial view. Picture credit: Dalman et al.

Picture credit: Dalman et al

Dr Fiorillo examined the fossils alongside his colleague Dr Spencer Lucas.  In addition, Sebastian Dalman (Montana State University), the lead author and co-authors Steven Jasinski (Harrisburg University), Edward Malinzak (Pennsylvania State University), and Martin Kundrát (Pavol Jozef Šafárik University in Slovakia) were involved in the research.

De Lucas commented:

“It seems like palaeontologists are discovering new dinosaurs in New Mexico every few months. This new hadrosaur just adds to my conviction that there are many, many new dinosaurs still out there waiting to be unearthed!”

To read an article from 2018 about the discovery of a new species of armoured dinosaur in New Mexico: A New Nodosaur from New Mexico.

A new species of chasmosaurine ceratopsian from New Mexico: The Chasmosaurine Bisticeratops.

A Novel Clade of Flat-headed Saurolophine Hadrosaurids

Although only some isolated skull material has been found, the scientists postulate that Ahshislesaurus lacked a head crest. The skull of Ahshislesaurus wimani preserves several taxonomically informative characters that show close affinities with the stratigraphically younger Naashoibitosaurus ostromi from the De-na-zin Member. Together with Naashoibitosaurus, Ahshislesaurus forms a potentially novel clade of flat-headed saurolophine hadrosaurids. This clade suggests the saurolophines were a taxonomically diverse group, which, during the last twenty million years of the Cretaceous, were among the dominant herbivorous dinosaurs in southern Laramidia.

Scientists are building up a detailed picture of the dinosaur fauna from the Late Cretaceous of New Mexico. Similar types of dinosaurs existed in southern Laramidia as those in more northerly parts of the landmass. However, the genera are different.  For example, the herbivorous Ahshislesaurus wimani co-existed with ankylosaurids and horned dinosaurs like Navajoceratops.  The apex predator was a tyrannosaur – Bistahieversor.

Ahshislesaurus wimani cervical vertebrae.

Proximal cervical vertebrae of the holotype of Ahshislesaurus wimani gen. et sp. nov., (USNM VP-8629); in right lateral view. Picture credit: Dalman et al.

Picture credit: Dalman et al

What’s in a Name?

This new hadrosaur taxon was named for the Ah-shi-sle-pah Wilderness in San Juan County, where its fossils were found. The specific epithet, “wimani”, honours the first Swedish professor of palaeontology, Carl Wiman (1867–1944), from Uppsala University, who worked on fossil vertebrates from the San Juan Basin. Recognition of a new hadrosaurid species from New Mexico also provides further evidence for latitudinal variation in the hadrosaurid fauna during the Late Cretaceous in Laramidia. In addition to the holotype of A. wimani, several specimens from the same strata may also belong to this newly identified species, including a well-preserved left dentary and a partial skeleton, as well as two humeri, one belonging to a large adult and the other to a juvenile.

The scientific paper: “A new saurolophine hadrosaurid (Ornithischia: Hadrosauridae) from the Upper Cretaceous (Campanian) Hunter Wash Member, Kirtland Formation, San Juan Basin, New Mexico” by Sebastian Dalman, Steven E. Jasinski, Dale Edward Malinzak, Spencer G. Lucas, Martin Kundrát and Anthony R. Fiorillo published in the New Mexico Museum of Natural History and Science Bulletin.

For scientifically accurate dinosaur models and figures visit the award-winning Everything Dinosaur website: Prehistoric Animal Models and Figures.

7 01, 2026

The First International Mammoth Conference to be Held in Africa

By |2026-01-10T06:36:00+00:00January 7th, 2026|Categories: Palaeontological articles|0 Comments

For the first time, the International Mammoth Conference heads to Africa. This decision marks a historic milestone. Importantly, it reflects the continent’s deep evolutionary significance. In January 2026, the National Museums of Kenya will host the “International Conference of Mammoths and their Relatives” in Nairobi. Scientists, academics, researchers, and enthusiasts will gather from across the globe. Together, they will share new insights into mammoths, mastodons, and their extinct relatives.

Crucially, proboscideans first evolved in Africa. Fossil evidence suggests the first proboscideans evolved around sixty million years ago (Palaeocene Epoch). Therefore, this setting feels especially fitting. It places cutting-edge research back at the group’s evolutionary roots. Furthermore, two of the remaining extant elephant species are in Africa.  Many proboscidean lineages evolved in Africa.  For example, deinotheres (family Deinotheriidae) are thought to have originated in Ethiopia.  A favourite Deinotherium figure is the Eofauna Scientific Research Deinotherium model.

Eofauna Deinotherium model.

The Eofauna Scientific Research Deinotherium model. A fantastic prehistoric elephant replica. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The team behind the Eofauna range of figures have conducted extensive research into prehistoric elephants.

To view the range of Eofauna Scientific Research models: Eofauna Scientific Research Figures.

The International Mammoth Conference

The “International Conference of Mammoths and their Relatives” is held every four years.  The inaugural conference took place in 1995. This quadrennial international meeting brings together leading researchers in this field of palaeontology. Moreover, conferences like this matter. They help strengthen academic networks beyond Europe and the United States. They also inspire regional students and researchers. As a result, interest in the natural world can grow more evenly worldwide.

Ultimately, this conference celebrates science, collaboration, and Africa’s vital role in palaeontology.

Mike from Everything Dinosaur commented:

“We wish the organisers and everyone attending an enjoyable and most rewarding conference.  It is great to see that this event is being held in Africa.  Perhaps, the conference will lead to greater cooperation between African universities and museums and their counterparts in Europe and North America.”

For models of prehistoric elephants and other prehistoric animals: Prehistoric Animal Models.

6 01, 2026

A New Parvicursorine Theropod from the Gobi Desert is Described

By |2026-01-07T15:02:24+00:00January 6th, 2026|Categories: Palaeontological articles|0 Comments

In the last few days of 2025, a bizarre new dinosaur taxon was scientifically described.  Researchers have published a paper about a fragmentary skeleton from the Upper Cretaceous (Maastrichtian) Nemegt Formation at Khermeen Tsav in the Gobi Desert of Mongolia.  Named Manipulonyx reshetovi, it has been assigned to the Parvicursorinae subfamily of the Alvarezsauridae.  The specimen includes an articulated and complete forelimb and crucially much of the manus (hand).  The single, large digit (digit I) is preserved.  However, evidence of rudimentary side fingers and a complete series of proximal carpal bones are also preserved.  This is the first time that proximal carpal bones have been identified in a parvicursorine.

Manipulonyx reshetov life reconstruction.

A life reconstruction of Manipulonyx reshetovi. Note the scale bar equals 10 cm. Picture credit: Tim Bollinger (TotalDino) with additional annotation by Everything Dinosaur.

Picture credit: Tim Bollinger (TotalDino) with additional annotation by Everything Dinosaur.

Our thanks to the artist Tim Bollinger for giving us permission to use his illustration of this recently described theropod. Tim’s website is a great resource with lots of amazing dinosaur images, updates and helpful information about the Dinosauria: Visit Total Dino.

Manipulonyx reshetovi

With the description of this new parvicursorine, palaeontologists have a much better understanding of the hand anatomy of this type of dinosaur.  In addition, they have hypothesised that parvicursorines specialised in eating eggs.  Therefore, the short forelimbs ended in highly specialised appendages that permitted these little theropods to hold and puncture the eggs of other dinosaurs.

The fossilised material consists of a pair of cervical vertebrae, one dorsal vertebra, sacral vertebrae and caudals. Moreover, the field team recovered fragmentary bones representing hindlimbs and part of the pelvic girdle. In contrast to the scrappy nature of this material, most of the bones from both forelimbs were found. The carpal bones indicate the presence of unique spikes on the wrist that would have helped this dinosaur to grasp and manipulate eggs. The enlarged claw on the powerful first digit is thought to have been used to puncture eggs so that the contents could be consumed.

Previous discoveries have suggested that parvicursorines could have been specialised insectivores.  It had been proposed that their specialised hands had evolved to help them dig for insects or for breaking into termite mounds.  For example, in 2022 we wrote an article about Dzharaonyx eski from Uzbekistan.

To read Everything Dinosaur’s blog post: The Remarkable “Old Dzharakuduk Claw”.

Were Some Alvarezsaurids Ovivores?

Alvarezsaurids are an unusual group of maniraptoran theropods. They evolved long hind limbs, compact bodies, and extremely reduced forearms. However, these arms were not useless. Instead, they supported a powerful, specialised manus. In most species, the hand appears adapted for a single dominant claw. This unusual body plan sets alvarezsaurids apart from all other theropods.

Within this family, Manipulonyx reshetovi belongs to the subfamily Parvicursorinae. These dinosaurs are typically lightly built and highly cursorial. Moreover, they show extreme forelimb modification. However, Manipulonyx goes much further. Its forelimbs preserve the wrist, metacarpals, and digits in near-complete condition. Notably, the manus shows reinforced elements and distinctive bony spikes. Therefore, researchers can assess how the hand functioned in life, not just how it looked.

The scientists writing in the Proceedings of the Zoological Institute of the Russian Academy of Sciences speculate that M. reshetovi was an egg-eater (ovivore).  This hypothesis builds on earlier discussions about alvarezsaurid diets.  For example, back in 2018 we authored an article about Qiupanykus zhangi, an alvarezsaurid from central China. At the time, it was speculated that Qiupanykus was an ovivore.

To read the blog post on Q. zhangiDid Alvarezsaurids Eat Eggs?

Mike from Everything Dinosaur commented:

“Manipulonyx reshetovi provides a rare and valuable window into parvicursorine evolution. Above all, its well-preserved forelimbs transform how we interpret alvarezsaurid behaviour and feeding strategies.  The forelimb is the most completely known of any parvicursorine and its discovery highlights the incredible diversity of the Dinosauria.”

The scientific paper is published in Proceedings of the Zoological Institute of the Russian Academy of Sciences.

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

4 01, 2026

The Remarkable Titanosaur Utetitan and the Return of Giant Sauropods to North America

By |2026-01-03T21:59:27+00:00January 4th, 2026|Categories: Palaeontological articles|0 Comments

The recent description of Utetitan zellaguymondeweyae marks a significant step forward in Late Cretaceous dinosaur research. This newly recognised titanosaurian sauropod lived during the Maastrichtian fauna stage in what is now Utah. Importantly, it challenges long-held assumptions about sauropod diversity in what we now know as North America.

For many years, palaeontologists believed that Alamosaurus sanjuanensis was the only sauropod present in North America during the final few million years of the Cretaceous. This idea always raised questions. After all, sauropods elsewhere often show multiple species living side by side. A single species persisting unchanged for such a long time seemed implausible.

The fossils that led to description of Utetitan come from the North Horn Formation, which dates to the very end of the Age of Dinosaurs. Although these remains were collected decades ago, they were historically placed within the Alamosaurus taxon. At the time, comparisons were difficult. Most sauropod fossils from the southwest and northern Mexico are fragmentary. Overlapping bones are rare. In addition, it is often difficult to compare fossil skeletons as they represent individuals at different growth stages.

A life reconstruction of Utetitan zellaguymondeweyae.

A life reconstruction of Utetitan zellaguymondeweyae. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Utetitan zellaguymondeweyae

Recent re-examination of the material revealed something important. The Utah fossils differ consistently from Alamosaurus fossils found in New Mexico. These distinctions are anatomical, not simply related to ontogeny or taphonomy. As a result, the Utah skeleton was designated as the holotype of a new species, Utetitan zellaguymondeweyae.

The name Utetitan honours the native Ute peoples of the region. Whereas the species name honours the author’s (Gregory S. Paul) maternal grandmother Zella Guymon Dewey (1901–2002).

The holotype includes tail vertebrae, pelvic bones, limb elements, and a distinctive osteoderm. Consequently, Utetitan is one of the most informative Late Cretaceous sauropods known from North America. Its anatomy confirms its place within the Titanosauria clade.

Many Different Titanosaurs Lived in Late Cretaceous North America

Crucially, Utetitan changes how palaeontologists view Late Cretaceous ecosystems. Evidence now suggests that multiple titanosaurs lived in southwestern North America during the Campanian and Maastrichtian faunal stages of the Late Cretaceous. Furthermore, some fossils from Texas may belong to Utetitan. Other fossils do not. Older Campanian remains cannot be confidently assigned to either Alamosaurus or Utetitan. This suggests that there are many more titanosaur genera awaiting scientific description.

These titanosaurs may even represent a short-lived regional lineage. In semi-isolation, they could have evolved separately from titanosaurs elsewhere in the world. Interestingly, new skeletal reconstructions suggest that these animals were not as massive as earlier size estimates indicated.

Alamosaurus scale drawing.

Scale drawing of Alamosaurus.  Recent research suggests that Alamosaurus sanjuanensis may not have been as large as previously thought.  Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

From a biogeographical perspective, Utetitan supports the idea of late sauropod migrations into North America. Changing sea levels may have opened temporary land corridors. Through these routes, titanosaurs could disperse from other continents.

Ultimately, the Utetitan zellaguymondeweyae paper shows how revisiting old fossils can transform scientific understanding.

The scientific paper: “Stratigraphic and anatomical evidence for multiple titanosaurid dinosaur taxa in the Late Cretaceous (Campanian-Maastrichtian) of southwestern North America” by Gregory S. Paul published as an open-access paper in Geology of the Intermountain West.

For models of Alamosaurus and other titanosaurs: Dinosaur Models.

3 01, 2026

Rare Azhdarchid Pterosaur Fossils From the Gobi Desert

By |2026-01-03T16:08:54+00:00January 3rd, 2026|Categories: Palaeontological articles|0 Comments

Palaeontologists have described two new species of azhdarchid pterosaurs from Mongolia’s Gobi Desert. The Gobi Desert is famous for its numerous dinosaur fossils. However, pterosaur remains are very rare in Mongolian Mesozoic deposits. Researchers writing in the academic journal “PeerJ” identified azhdarchid pterosaur fossils.

The material consists of bones from the neck, and from these specimens two new species have been erected. The fossils come from two different localities (Bayshin Tsav and Burkhant). Originally collected in the 1990s, the fossils were described in detail in 2009 (Watabe et al). Yet, at the time the pterosaurs were not named, just described as indeterminate azhdarchids.

Azhdarchid Pterosaur Fossils

Subsequently, knowledge of azhdarchid pterosaur anatomy has improved. As a result, two distinct species have been named.  In a paper published in the autumn, researchers identified diagnostic features permitting the establishment of these two new species. The paper was written by researchers from the Universidade de São Paulo (Brazil), Shihezi University (China) and Hokkaido University (Japan).

Azhdarchid pterosaur fossils lead to the naming of two new taxa.

Azhdarchid pterosaur fossils lead to the naming of two new taxa. The two new Mongolian taxa are compared to two of the largest azhdarchid pterosaurs. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Gobiazhdarcho tsogtbaatari: A Medium-Sized Pterosaur

The first species is named Gobiazhdarcho tsogtbaatari. It comes from the Burkhant locality of the Bayanshiree Formation. This pterosaur had an estimated wingspan of three to three and a half metres. It has been described as a medium-sized azhdarchid, with a wingspan roughly comparable to an Andean Condor (Vultur gryphus).  Fossils associated with this taxon include an atlantoaxis (fused neck vertebrae) and other cervical bones. These show it belonged to a lineage related to giants such as Quetzalcoatlus and Arambourgiania. In evolutionary terms, Gobiazhdarcho is a basal member of this quetzalcoatlid group, bridging gaps in the fossil record.

Its name reflects both its origin and scientific heritage. “Gobi” refers to the desert where it was found. “Azhdarcho” comes from Persian for dragon. The species name honours Mongolian palaeontologist Khishigjav Tsogtbaatar.

Tsogtopteryx mongoliensis: A Small Azhdarchid Pterosaur

The second species named in the paper is Tsogtopteryx mongoliensis. This pterosaur is notably small for an azhdarchid. Its estimated wingspan was approximately two metres, making it one of the smallest members of the Azhdarchidae family.  A single, partial mid-cervical vertebra is known for this species. Despite the limited material, distinct features show it belongs to a different pterosaur lineage than Gobiazhdarcho.  It was related to Hatzegopteryx. This lineage includes robust-necked azhdarchids previously known only from Europe.

The genus name combines the Mongolian word “Tsogt” (meaning mighty hero) with the Greek word pteryx which means wing. The species name references its discovery in Mongolia.

Azhdarchids Occupied Diverse Ecological Niches

The coexistence of Gobiazhdarcho and Tsogtopteryx in the same geological formation emphasises that azhdarchids occupied diverse ecological niches. Different body sizes suggest varied foraging behaviours and diets. This pattern echoes findings from other Upper Cretaceous deposits.  This study sheds fresh light on the diversity and phylogeny of azhdarchid pterosaurs. It reinforces the reoccurring pattern of coexistence between multiple, differently-sized azhdarchid species within the same palaeoenvironment.

The scientific paper: “Azhdarchid pterosaur diversity in the Bayanshiree Formation, Upper Cretaceous of the Gobi Desert, Mongolia” by R. V. Pêgas, Xuanyu Zhou​ and Yoshitsugu Kobayashi published in PeerJ.

For pterosaur models and other prehistoric animal figures: Pterosaur Models and Prehistoric Animal Figures.

10 12, 2025

The First Evidence of Colour Patterning in Sauropod Dinosaur Skin

By |2026-01-01T14:19:42+00:00December 10th, 2025|Categories: Palaeontological articles|0 Comments

A new study published by the Royal Society Open Science reveals colour patterning in sauropod dinosaur skin.  Interpretation of the preserved integumentary covering has led scientists to suggest that the dull grey, elephant-like colouration of sauropods is probably inaccurate.  The peer-reviewed study was led by Tess Gallagher (Department of Palaeobiology, University of Bristol), and it provides exciting new information on the Sauropodomorpha.

This is the first reported evidence of colour patterning in a sauropod.  Exceptionally preserved juvenile diplodocid (Diplodocus) skin impressions from Montana formed the basis of this study. The fossils come from the Mother’s Day Quarry (Morrison Formation) and for the purposes of this study they were ascribed to Diplodocus. However, the taxonomic classification of these sauropods might change with future research.

Sauropod dinosaur skin life reconstruction.

Sauropod dinosaur skin speculative life reconstruction with graphic microscopy (inset). Picture credit: Tess Gallagher.

Picture credit: Tess Gallagher

Studying Sauropod Dinosaur Skin

One of the key conclusions from the research is the confirmation of the presence of two distinct microbody morphotypes associated with the integument. These structures have been identified as melanosomes.  Therefore, they are linked to pigmentation and colouration. The different shapes of these microbodies indicates that young sauropods may have displayed visual patterning rather than being a single uniform colour.

A sample of Diplodocus fossilised skin from the Mother's Day Quarry site.

Elevation Science student holding a sample of Diplodocus fossilised skin. Picture credit: Joshua Levy.

Picture credit: Joshua Levy

It is possible that juvenile Diplodocus had complex colour patterning. Perhaps, these leviathans had similar colouration to extant archosaurs such as birds.

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

The new for 2020 CollectA rearing Diplodocus dinosaur model in the elephantine colour scheme. Many sauropods are depicted with a uniform colouration. This colouration has been inspired by large mammals alive today.  However, new research suggests that Diplodocus had complex colour patterning. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Difficult to Confirm the Exact Colours

The first sauropod to be scientifically described from fossilised bones was Cetiosaurus (1842 – Owen). Initially thought to be aquatic lizards, these animals were mainly terrestrial and some of them grew to enormous sizes.  Some taxa are regarded as the largest land animals that have ever existed.  Although dozens of genera have been named, evidence for their colouration is lacking.  This research provides a rare insight into the colouration of juvenile sauropods and opens new avenues for studying dinosaur biology and behaviour.

Commenting on the significance of the research, Tess Gallagher (University of Bristol) stated:

“This study investigates fossilised juvenile Diplodocus scales and marks the first instance of colour patterning found in a long-necked dinosaur. The skin is preserved 3-dimensionally as clay minerals with melanosome groups (melanin bearing organelles) dispersed throughout. Disk-shaped objects were found intermixed with the melanosomes. The disk-shaped objects are hypothesized to be melanosomes, though their bizarre shape makes it impossible to determine the true colour of the scales. Regardless, the results show juvenile sauropods could create more diverse melanosome morphologies than previously thought, akin to modern birds and mammals.”

Tess Gallagher holding a preserved skin impression.

Field photo of Tess Gallagher holding a preserved skin impression. Picture credit: Skye Walker/Elevation Science Institute.

Picture credit: Skye Walker/Elevation Science Institute.

The Significance of Integumentary Fossils

Remarkable, well-preserved integumentary fossils have the potential to help us learn more about dinosaur physiology. In addition, we can infer ecological niches and the appearance of dinosaurs in terms of their colouration.

Co-author of the paper, Jason Schein (Executive Director of Elevation Science for Natural History Exploration) added:

“It wasn’t that long ago when it seemed impossible that we could even really know what dinosaurs truly looked like. Technology and innovative scientists like Tess are pushing us into new frontiers, and showing us what is actually possible.”

Everything Dinosaur acknowledges the assistance of a media release from the Elevation Science Institute for Natural History Exploration in the compilation of this article.

The scientific paper: “Fossilized melanosomes reveal colour patterning of a sauropod dinosaur” by Tess Gallagher, Dan Folkes, Michael Pittman, Tom G. Kaye, Glenn W. Storrs and Jason Schein published in the Royal Society Open Science.

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

6 12, 2025

New Study Highlights Ancient “Drop Crocs” from Australia

By |2025-12-29T06:58:45+00:00December 6th, 2025|Categories: Palaeontological articles|0 Comments

A recently published paper highlights Australia’s oldest known crocodilian eggshells.  The study is helping researchers from the University of New South Wales to unlock clues to an ancient ecosystem that thrived before Australia became an island continent.  The eggshell fragments have been assigned to the oospecies Wakkaoolithus godthelpi.

The fossilised fragments of eggshell are approximately fifty-five million years old (Eocene Epoch).  The come from mekosuchine crocodiles.  These now extinct crocodiles dominated inland waters during the Eocene.  Modern saltwater and freshwater crocodiles only arrived in Australia around 3.8 million years ago.

Wakkaoolithus godthelpi eggshell fragments.

Electron microscope scans of the eggshell fragments. Picture credit: Xavier Panadès.

Picture credit: Xavier Panadès

Field teams have been working in clay pit close to the small town of Murgon in southeast Queensland. The clay layers preserve evidence of when Australia was still connected to South America and Antarctica.  It is one of the oldest fossil sites in Australia.  An international research team led by the Institut Català de Paleontologia Miquel Crusafont (ICP) in collaboration with researchers from University New South Wales (UNSW) identified the mekosuchine fossil eggshells.

Commenting on the significance of the fossil finds, lead author of the study Xavier Panadès i Blas (El Museu de la Conca Dellà, Isona, Spain), stated:

“These eggshells have given us a glimpse of the intimate life history of mekosuchines. We can now investigate not only the strange anatomy of these crocs, but also how they reproduced and adapted to changing environments.”

Wakkaoolithus godthelpi artwork generated by AI.

A virtual reconstruction of the Murgon palaeoecosystem during the Early Eocene, featuring the oospecies Wakkaoolithus godthelpi. Also shown is one of the abundant giant soft-shell turtles, Murgonomys braithwaitei, an archaic marsupial, Djarthia murgonensis, and an unnamed ancestral songbird. The clays that form the fossil deposit were accumulated in this ancient lake. Image: generated with Google Gemini AI.

Picture credit: Google Gemini AI

Swimming and Tree Climbing Crocodiles

Unlike Australia’s crocodiles today, mekosuchines filled much more varied ecological niches.  For example, some species were almost entirely terrestrial and inhabited forests.  Others were at home in the river systems and grew to at least five metres in length.  Co-author of the paper, Professor Michael Archer (UNSW) has postulated that some species were at least partly arboreal, and these animals have been termed “drop crocs.”

Professor Archer added:

“They were perhaps hunting like leopards – dropping out of trees on any unsuspecting thing they fancied for dinner.”

Fieldteam working on the Tingamarra clay deposits. It is from these deposits the the oospecies Wakkaoolithus godthelpi has been discovered.

The palaeontological team from UNSW excavating the Tingamarra fossil deposit at Murgon, Queensland, Australia. The hard clay is quarried, dried and then soaked in water to release the fossils it contains. Photo credit: Mina Bassarova.

Picture credit: Mina Bassarova

Delicate Time Capsules

The authors state that tiny, fossilised eggshells are an underused resource in vertebrate palaeontology.  They preserve microstructural and geochemical signals that provide information on the kinds of creatures that laid them but also where they nested and how they bred.

Xavier Panadès i Blas explained:

“Our study shows just how powerful these fragments can be.  Eggshells should be a routine, standard component of palaeontological research – collected curated and analysed alongside bones and teeth.”

The shell fragments from the clay pit were examined under optical and electron microscopes.  Their microstructure indicates that they were laid on the margins of a lake, with the reproductive strategy adapting to fluctuating conditions.

Co-author of the study, Dr Michael Stein (UNSW), commented that mekosuchine crocs may have lost much of their inland territory because of encroaching dry land.  These crocodiles eventually had to compete in the shrinking waterways not only with new crocodilian rivals arriving in Australia but also with dwindling numbers of prey.  As the climate became much drier, many of the large prey animals that these crocodiles hunted became rarer.

The researchers think that the lake was surrounded by a lush, tropical forest.

Dr Stein said:

“This forest was also home to the world’s oldest-known songbirds, Australia’s earliest frogs and snakes, a wide range of small mammals with South American links, as well as one of the world’s oldest bats.”

Wakkaoolithus godthelpi eggshell fragments shown in high magnification.

Wakkaoolithus godthelpi eggshell fragments shown in high magnification. Picture credit: Xavier Panadès.

Picture credit: Xavier Panadès

A Study with Teeth

The research into the Tingamarra deposits at Murgon is just part of a much bigger story.  Professor Archer recalls finding a bizarre crocodilian jaw fragment in 1975 in the Texas Caves of southeastern Queensland.  This jaw fossil has been confirmed to represent a mekosuchine crocodile.  The large teeth in situ were linked to another type of extinct crocodile known from South America.  This was the first evidence of crocodiles related to South American crocodiles being present in Australia during the Eocene.

Discoveries like this are more than just a glimpse into ancient history. They are reminders that Australia’s fossil record can provide important clues to help save today’s threatened species. For example, scientists have been working to help bring a small possum – Burramys parvus back from the brink of extinction.  Researchers discovered that the possum’s prehistoric relatives, evolving over the past twenty-five million years, have always thrived in temperate lowland rainforests.

This led to the theory that the immediate ancestors of B. parvus likely followed the rainforests as they moved up into the alpine areas during a warm, wet interval during the Pleistocene Epoch. However, when the climate in the alpine zone changed and became cooler, these small marsupials had to evolve evasive behaviours such as hibernation to escape the increasingly hostile conditions.

Based on the findings from the fossil record a breeding facility in an area of non-alpine rainforest was set up.  As a result, the numbers of Burramys parvus have increased.  The possums are flourishing in a non-alpine sanctuary, just as the fossil record predicted.

Wakkaoolithus godthelpi Fossils Provide Guidance to Conservationists

As climate change threatens Australia’s fauna today, the fossil record can provide important indicators to assist with the conservation of species.

Professor Archer stated:

“Clues from the fossil record matter.  Not just to understand the past, but also to help secure the future”.

The new crocodile species’ name, Wakkaoolithus godthelpi, acknowledges, with permission, the Wakka Wakka First Nations people, on whose Country the fossils were found. The second part of the name recognises Henk Godthelp, who was part of the UNSW palaeontologist crew along with Professor Archer, Professor Sue Hand and many other research staff and students.

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

The scientific paper: “Australia’s oldest crocodylian eggshell: insights into the reproductive paleoecology of mekosuchines” by Xavier Panadès I Blas, Àngel Galobart, Michael Archer, Michael Stein, Suzanne Hand and Albert Sellés published in the Journal of Vertebrate Paleontology.

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

5 12, 2025

New Nanotyrannus Paper Strengthens Unique Taxon Theory

By |2025-12-16T14:34:11+00:00December 5th, 2025|Categories: Palaeontological articles|0 Comments

A recently published scientific paper lends weight to the theory that Nanotyrannus is a valid taxon.  Writing in the journal “Science” a team of scientists, including researchers from the Cleveland Museum of Natural History used a novel approach to confirm that a skull does indeed represent skeletally mature adult.  Their evidence confirms that the fossil specimen, known as the “Cleveland skull” does not represent a juvenile Tyrannosaurus rex.  An often-overlooked bone helped make the breakthrough.  The Nanotyrannus hyoid bone provided the vital information.

Whether Nanotyrannus lancensis represents a distinct taxon or an immature T. rex is a decades-long controversy.  This new study comes shortly after a paper that concluded that Nanotyrannus was a valid taxon.  Indeed, this study claimed that there were two species of Nanotyrannus in the known fossil record.

To read Everything Dinosaur’s blog post about this earlier study: Nanotyrannus – A New Chapter in Tyrannosaur Evolution.

The "Cleveland skull" - Nanotyrannus lancensis fossil material.

The “Cleveland skull” – Nanotyrannus lancensis fossil material. Picture credit: Cleveland Museum of Natural History.

Picture credit: Cleveland Museum of Natural History

The Cleveland Skull

The Cleveland skull lies at the heart of this long-running controversy. Discovered in 1942, the specimen consists almost entirely of a skull, with no associated postcranial bones. As a result, palaeontologists found it difficult to determine whether these fossils represented a juvenile tyrannosaur or an adult animal. If the fossil skull represented an adult, then this would indicate a new tyrannosaur genus present in Hell Creek. Hence, the erection of a new tyrannosaur species (Gorgosaurus lancensis) in a paper published posthumously in 1946 by the American palaeontologist Charles Whitney Gilmore.

Dr Caitlin Colleary examining Nanotyrannus skull material.

Dr Caitlin Colleary (Department of Earth Sciences, Cleveland Museum of Natural History), examining the Nanotyrannus skull material. Picture credit: Cleveland Museum of Natural History.

Picture credit: Cleveland Museum of Natural History

The Nanotyrannus Hyoid Bone

One small bone proved vital when trying to assess the skull material. The Nanotyrannus hyoid bone had detached from the skull and was stored separately in the museum collection. This slender throat bone had gone largely unnoticed until a visiting researcher recognised its potential importance. The hyoid supports the tongue and airway in living animals. Crucially, it also records growth in a measurable way. The researchers were able to demonstrate that the histology preserved in this bone was useful for assessing the ontogeny of the fossils. The research team therefore applied histological analysis to the hyoid, an approach never used on this bone before.

Before examining the Cleveland specimen, the scientists validated their method. They studied hyoids from birds and crocodilians, which represent living dinosaur relatives. They then compared the Nanotyrannus hyoid bone with those from theropod dinosaurs including Tyrannosaurus rex, Allosaurus, and Coelophysis.

Thin sections viewed under a microscope revealed clear growth patterns. Most importantly, the hyoid contained an external fundamental system. This structure forms when growth has ceased. The team demonstrated that hyoid bone histology is useful for ontogenetic assessment in extant and extinct archosaur.

Senior author of the paper, Dr Caitlin Colleary (Department of Earth Sciences, Cleveland Museum of Natural History), explained:

“By applying a new technique to a specimen that’s been in the collection for nearly 80 years, we unlocked information that’s been there all along.”

The Cleveland Skull Material Represents a Fully Grown Animal

The presence of this feature confirms that the Cleveland skull fossils belonged to a fully grown individual. It did not represent a juvenile Tyrannosaurus rex. Instead, it supports the interpretation of Nanotyrannus lancensis as a distinct taxon coeval with T. rex.

An adult Nanotyrannus lancensis competes for food with a juvenile T. rex.

A Nanotyrannus (N. lancensis) left, competes for food with a juvenile Tyrannosaurus rex, whilst an adult T. rex watches in the background. Picture credit: Andrey Atuchin.

Picture credit: Andrey Atuchin

Nanotyrannus Hyoid Bone Study – The Implications

This study has significant implications for tyrannosaur research. The holotype defines the species. Demonstrating adult status strengthens the case for Nanotyrannus beyond reasonable doubt. The study also highlights the enduring value of museum collections. A single overlooked bone provided the decisive evidence. Sometimes, the most important discoveries wait quietly in storage.

For the moment, the debate has shifted decisively. The Nanotyrannus hyoid bone offers direct proof of skeletal maturity. As a result, this small tyrannosaur finally steps out from the shadow of Tyrannosaurus rex.  This study and the earlier Nanotyrannus paper, indicate that the Hell Creek ecosystem was home to a wide assemblage of predatory dinosaurs.

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

The scientific paper: “A diminutive tyrannosaur lived alongside Tyrannosaurus rex” by Christopher T. Griffin, Jeb Bugos, Ashley W. Poust, Zachary S. Morris, Riley S. Sombathy, Michael D. D’Emic, Patrick M. O’Connor, Holger Petermann, Matteo Fabbri and Caitlin Colleary published in the journal Science.

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