A team of international scientists have described a new species of hadrosaur from the end of the Cretaceous. The dinosaur, from Coahuila in northern Mexico has been named Coahuilasaurus lipani. The cranial material used to describe this new duckbill dinosaur was previously identified as Kritosaurus. A closer examination revealed unique autapomorphies of the snout and beak that led to the establishment of this new taxon. Along with other recent dinosaur discoveries from Mexico, Coahuilasaurus shows that Mexico had different species of dinosaurs than the United States and Canada.

Coahuilasaurus lipani life reconstruction. Picture credit: C. Díaz Frías.

Picture credit: C. Díaz Frías

Coahuilasaurus lipani

The new duckbill is known from the front end of a skull. Coahuilasaurus differs from related species in having a very short, deep muzzle and a series of tooth-like projections on the roof of the mouth. The unusual morphology of the jaws suggests a specialisation for the consumption of tough vegetation like palms and cycads.

In recent years, scientists have found a rich fauna of dinosaurs in northern Mexico, like the horned dinosaur (Coahuilaceratops), the crested duckbills Velafrons and Tlatolophus, and now a new kritosaurin hadrosaurid Coahuilasaurus.  Mexico in the Late Cretaceous was very different from today.  It was not an arid, desert environment.  Instead, it was a tropical rainforest full of palm trees and bananas, bordering the Gulf of Mexico.

The Cerro del Pueblo Formation, in Coahuila State, Mexico. Picture credit: Longrich et al.

Picture credit: Longrich et al

An article from 2008 providing information on the discovery of Velafrons coahuilensis: Duckbilled Dinosaur from “South of the Border”.

A blog post from 2010 about the ceratopsian Coahuilaceratops magnacuerna: A New Genus of Horned Dinosaur.

To read a blog post from 2021 about the discovery of Tlatolophus galorum: A New Lambeosaurine from the Gulf of Mexico.

The Different Dinosaur Biotas of Laramidia

Further north, in the USA and Canada, completely different dinosaurs existed. For example, the duckbill Edmontosaurus and the ceratopsian Pachyrhinosaurus. The identification of a new taxon fits the pattern where dinosaurs in the south are distinct from the ones in the northern parts of the ancient landmass of Laramidia.

The dinosaur biota of the Cerro del Pueblo Formation. Picture credit: Longrich et al.

Picture credit: Longrich et al

There are lineages of dinosaurs that disappear from the north but persist for longer in the south. The southern dinosaurs seem to be very different from the northern dinosaurs, so it may be that a lot of what we think we know – including what dinosaur diversity was doing at the very end of the Cretaceous is biased by the fact that until now palaeontologists have been more focused on the dinosaur biota from northern Laramidia.

A drawing of the skull of Coahuilasaurus lipani with known bones show in white (A). A silhouette of C. lipani (B), note the scale bar in (A) of 20 cm and (B) one metre. Picture credit: Longrich et al.

Picture credit: Longrich et al

Commenting on the significance of this new dinosaur discovery Dr Nick Longrich (University of Bath), and a co-author of the study stated:

“Dinosaurs apparently had very small geographic ranges compared to modern mammals, which often range across entire continents. Which is bizarre given that big animals tend to have huge ranges. But what this means is that even in a relatively small area like western North America, you could pack huge numbers of species into a small landmass. Since we’ve only explored a few places for dinosaurs, that implies there’s a huge diversity of dinosaurs waiting to be discovered.”

More Dinosaur Discoveries from Mexico are Likely

Some of those dinosaurs may never be found.  For example, some may never have been preserved as fossils. The remains of others are buried far beneath the ground, or their fossils eroded out millions of years ago and have been weathered away. However, in Coahuila there are vast regions of desert that have hardly been explored.  It is likely that more dinosaur fossils representing new taxa will be discovered in northern Mexico.

The holotype of Coahuilasaurus lipani. The unique morphology of the skull and jaws led to the establishment of a new species of kritosaurin hadrosaurid. Picture credit: Longrich et al.

Picture credit: Longrich et al

Dr Longrich added:

“Canada and the United States have been pretty well-explored at this point. We’ll keep finding new dinosaurs there, but it’s slow going, the low-hanging fruit, the common species we’ve found. Mexico is terra incognita. There’s a lot of dinosaurs waiting to be discovered, we just need to get out there and find them.”

Everything Dinosaur acknowledges the assistance of the Department of Life Sciences (Bath University) and Dr Nicholas Longrich for the compilation of this article.

The scientific paper: “Coahuilasaurus lipani, a New Kritosaurin Hadrosaurid from the Upper Campanian Cerro Del Pueblo Formation, Northern Mexico” by Nicholas R. Longrich, Angel Alejandro Ramirez Velasco, Jim Kirkland, Andrés Eduardo Bermúdez Torres and Claudia Inés Serrano-Brañas published in the journal MDPI Diversity.

The Everything Dinosaur website: Prehistoric Animal Models and Toys.

Cacti (Cactaceae family) are a remarkably diverse group of plants.  Some are a few centimetres in size.  Moreover, others have tree-like habits such as the giant Pachycereus pringlei otherwise known as the elephant cactus.  This cactus can reach heights in excess of fifteen metres.  Their strange shapes and multiple spines might make you think that these angiosperms are truly ancient, perhaps amongst the first flowering plants to evolve.  However, the origins of the Cactaceae family might be relatively recent.  A new study by the Milner Centre for Evolution at the University of Bath has shed new light on cacti evolution and the mystery as to their remarkable diversity.

Cacti Evolution and Diversity

It had been thought that the dryness of the climate was the main driver in cacti evolution.  This new research published in “Nature Communications” challenges this view.  The study found that diurnal temperature range, sand content in the soil and seasonal changes are the biggest drivers of cacti evolution.

Cacti are popular house plants.  However, whilst they have a global distribution today, being found in homes all over the world, they are in fact native to the Americas.  The highest number of species are to be found in Mexico.

In a bid to better understand the diversity of the Cactaceae family and their evolution, researchers built the largest evolutionary tree for cacti.  The data tree was compiled using detailed DNA sequences.  Numerous biological variables were considered, including soil sand composition, plant size, geographical range, aridity and diurnal temperature range.  The diurnal temperature range measures the difference between the maximum and the minimum temperatures experienced over a day.  This database was then correlated using data on biodiversity and the perceived rates of the evolution of new species.

Cacti evolution outlined in a new scientific study. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

 Machine Learning

The team used sophisticated machine learning techniques to model the interactions between several variables simultaneously.  Results were then validated using traditional evolutionary methods. Surprisingly, the team found that whilst the highest number of species was found in Mexico, the country also had the lowest evolution rates of new species (speciation).

Aridity was previously assumed to be the main driving factor of their evolution.  However, the new study points to the diurnal temperature range, sand content in the soil and seasonality as being more important drivers of cacti evolution.

Commenting on the results, first author Dr Jamie Thompson stated:

“Cacti are a really interesting, diverse family of plants that have evolved relatively recently in evolutionary time to live in a wide range of environments across the American continents. People think they are very hardy because they are able to live in such extreme climates, but in fact they are more at risk of extinction than other types of plants.”

The doctor carried out the research whilst at the Milner Centre for Evolution (University of Bath), however he has moved on to become a lecturer at the University of Reading.

He added:

“Because there is the highest biodiversity in Mexico, it was assumed this was because the conditions there were best for evolution of species. However, our study shows this isn’t the case – instead Mexico has the slowest rate of speciation but has lots of biodiversity because the extinction rates are slower. In other words, the Mexican climate is not necessarily better at producing new species but good at preserving existing ones.”

A small cactus. Around 1,750 species have been described. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

When Did Cacti Evolve?

Team members are not aware of any definitive Cactaceae fossils having been found. It is difficult to establish their evolutionary origins. However, the geographical distribution of cacti can offer a clue. Wild cacti are found in South America and the southern parts of North America. This suggest that the cacti family evolved after the fragmentation of Gondwana and the splitting off of South America from the rest of the landmass. This suggest that the ancestors of today’s cacti evolved in the Early Cretaceous.

In contrast, molecular studies suggest that the Cactaceae are a more recent lineage of angiosperms. These studies suggest that the first cacti evolved during the late Eocene or early Oligocene Epochs. During this time, it is thought that the world became drier. The increased aridity led to a decline in forest habitats, and this may have helped fuel the evolution of plants adapted for water conservation.

Commenting on the research, co-author Dr Nick Priest (University of Bath) explained:

“Our work shows that cacti are not as successful as we thought, and are more vulnerable to climate change. This is concerning – if cacti can’t thrive in our changing climate, what chance do other plants have?”

The research team included scientists from the University of Reading, the Desert Botanical Garden (Phoenix, Arizona) and the Tecnológico Nacional de México (Mexico).

For a recent article highlighting the discovery of nine new species of ancient grapes: Nine New Species of Fossil Grape Identified in Study.

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

The scientific paper: “Identifying the multiple drivers of cactus diversification” by Jamie B. Thompson, Tania Hernández-Hernández, Georgia Keeling, Marilyn Vásquez-Cruz and Nicholas K. Priest published in Nature Communications.

The Everything Dinosaur website: Prehistoric Animal Toys.

The summer excavations at the world famous Bromacker fossil site in Germany have concluded. Hundreds of new fossil discoveries have been recorded.  The Bromacker Lagerstätte is considered one of the most important fossil sites in Germany. An international research team, consisting of experts in palaeontology, geology, fossil preparation and collection management have been working at the site for four weeks. They have unearthed amazing fossil discoveries.  New finds include vertebrate fossil remains, trace fossils, ancient crustaceans, plant imprints and insect wings.  In addition, over the course of the dig programme the scientists received over 2,300 visitors.  Members of the public taking an active interest in the exploration of deposits laid down in the Permian.

Field team members working at the famous Bromacker fossil site. Picture credit: Anastasia Voloshina/Museum für Naturkunde, Berlin.

Picture credit: Museum für Naturkunde (Berlin)

The Remarkable Bromacker Fossil Site

Researchers from the Museum für Naturkunde Berlin, the Friedenstein Foundation Gotha, the Friedrich Schiller University Jena and the UNESCO Global Geopark Thuringia Inselsberg – Drei Gleichen are involved in the project.  The fossils are approximately 290 million years old.  They present a record of a unique Palaeozoic ecosystem. The exceptionally well-preserved fossils provide information on the development of early terrestrial vertebrates.  New finds include fragments of a skull incorporating a jaw with long, thin teeth.

Since 2020, over three hundred and fifty finds have been documented each year. New taxa have been described based on Bromacker fossil site discoveries. For example, two recent early vertebrates have been named (Bromerpeton subcolossus and Diadectes dreichgleichenensis).

To read about the discovery of B. subcolossus: A New Lower Permian Amphibian is Named.

To learn more about Diadectes dreichgleichenensis: A Newly Described Early Tetrapod from the Bromacker Fossil Site.

Project and excavation manager Professor Jörg Fröbisch, from the Museum für Naturkunde, Berlin was very pleased with this season’s finds.

The professor commented:

“This year’s excavation at Bromacker was once again a complete success and far exceeded our expectations. The finds include numerous and varied trace fossils of invertebrates and vertebrates, including walking, swimming, scratching tracks and burrows.  By discovering and researching the prehistoric dinosaur bones and small skeletons, trace fossils, prehistoric crustaceans, plant imprints and insect wings, we hope to gain further insights into the entire ecosystem at Bromacker 290 million years ago.”

Piecing Together the Palaeoclimate

Some of the small invertebrate and plant remains are particularly significant.  For example, the crustaceans found are reminiscent of extant forms that live in temporary pools and puddles.  Therefore, if they occur in clusters in the Bromacker deposits, it can be inferred that these remains represent evidence of flooding.  The plant root finds indicate that other parts of the Bromacker fossil site were not as prone to flooding events.

The scientists hope to publish several papers based on these new, exciting fossil discoveries.

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

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

Earlier this year, researchers revealed the discovery of a new titanosaur from Patagonia.  The dinosaur named Titanomachya gimenezi comes from northern Chubut Province in central Patagonia. Several titanosaur taxa have been reported from northern Patagonia, as well as few titanosaurs from southern Patagonia. However, titanosaurs from the end-Cretaceous of central Patagonia are poorly known. The fossil specimen represents an adult animal. It is described as a small-bodied saltasauroid. However, despite being small by titanosaur standards, it has been estimated that Titanomachya weighed around 8 tonnes (weight estimates range from 5.8 to 9.8 tonnes).

Titanomachya gimenezi life reconstruction. Picture credit: Gabriel Diaz.

Picture credit: Gabriel Diaz

Fossils from the La Colonia Formation

The fossils come from La Colonia Formation and the research team consisted of Agustín Pérez Moreno, Leonardo Salgado, José Luis Carballido, Alejandro Otero, and Diego Pol. These eminent researchers herald from a variety of Argentinian institutions including the Museo de La Plata (MLP), the Museo Paleontológico Egidio Feruglio (MEF) and the Fundación Félix de Azara-Universidad Maimónides.

Titanomachya gimenezi fossil excavation. Picture credit: Vincent Brusca.

Picture credit: Vincent Brusca

The strata in which the fossils were found date from the Upper Cretaceous (Maastrichtian faunal stage).  This indicates that Titanomachya gimenezi roamed this part of Gondwana around seventy million years ago.  The genus name is derived from the Titanomachy, a mythical battle fought by the Olympian gods against the Titans in Greek mythology.  In this battle, the Titans lost.  The name is appropriate and fitting since Titanomachya comes from the time when the titanosaurs were heading for extinction.  The species name honours the late Dr Olga Giménez.  Dr Giménez played a pivotal role in the study of vertebrate fossils found in central Patagonia.  She was the first palaeontologist to study the dinosaurs of the Chubut province.

Field team members excavating the fossils. Picture credit: Vincent Brusca.

Picture credit: Vincent Brusca

Studying the Fossil Material

More than fifteen scientists have been involved in the field work.  The excavation work was carried out over two years and the fossil material found consists of elements from the limbs along with fragments of ribs and a caudal vertebra.  Once exposed, the fossils were jacketed with burlap and plaster and sent to the MEF laboratories for preparation.

Skeletal reconstruction of Titanomachya gimenezi. The bones coloured blue represent the known fossil material. Picture credit: Gabriel Lio.

Picture credit: Gabriel Lio

This newly described titanosaur is the smallest known from central Patagonia.  Titanomachya (pronounced tie-tan-om-mack-ee-ah), may have measured around ten metres long when fully grown.  It was similar in size to Neuquensaurus australis and Saltasaurus loricatus, to which it was closely related.  The research team identified several unique autapomorphies which allowed them to confidently erect a new taxon.  For example, the astragalus (bone from the ankle), demonstrates unique morphology.  It shows intermediate traits between the Saltasauroidea titanosaurs and the Colossosauria clade of titanosaurs.  These autapomorphies highlight the significance of this discovery as it provides an evolutionary link between different types of sauropod.

Furthermore, phylogenetic studies have demonstrated that Titanomachya is a derived titanosaur. It is a member of the great Saltasauroidea lineage.

Titanomachya gimenezi fossils exposed on the surface. Picture credit: Vincent Brusca.

Picture credit: Vincent Brusca

Titanomachya gimenezi and the South America Titanosaur Biota

The La Colonia formation has also yielded the famous theropod Carnotaurus as well as other material.  Fossils representing other carnivorous dinosaurs have been discovered.  For instance, the recently described abelisaurid Koleken (K. inakayali).

To read more about Koleken: A New Abelisaurid from Southern Argentina.

In addition, the remains of ornithischian dinosaurs have been found.  However, Titanomachya gimenezi represents one of only a handful of defined taxa and the first sauropod known from this formation.  This discovery sheds light on the diversity of the region’s ecosystems at the very end of the Age of Dinosaurs.  Moreover, it provides crucial data regarding the composition of sauropod populations in Patagonia during the Maastrichtian.

The researchers postulate that distinct sauropod faunas existed in different parts of Patagonia and also in Brazil over the Campanian and Maastrichtian Epochs. In northern Patagonia, aeolosaurines and saltasaurines dominated, whilst in southern Patagonia, the sauropod biota mostly comprised colossosaurians and other large titanosaurs. In contrast, the less well-known sauropod fauna from central Patagonia seems to have consisted of small-bodied saltasauroids such as Titanomachya along with members of the aeolosaurini and derived eutitanosaurs.

Titanomachya gimenezi in its low-lying coastal habitat. Picture credit: Gabriel Diaz.

Picture credit: Gabriel Diaz

Further Research Planned

Summarising their research to date, the scientists suggest that Titanomachya provides a new perspective on the rich history of sauropods in Patagonia.  In addition, this unique specimen opens the door to future research that will explore the diversity and evolution of these amazing herbivores.

Everything Dinosaur acknowledges the assistance of corresponding author Dr Pérez Moreno CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas), Buenos Aires, Argentina, in the compilation of this article.

The scientific paper: “A new titanosaur from the La Colonia Formation (Campanian-Maastrichtian), Chubut Province, Argentina” by Agustín Pérez-Moreno, Leonardo Salgado, José L. Carballido, Alejandro Otero and Diego Pol published in Historical Biology.

Visit the Everything Dinosaur website: Dinosaur Models and Toys.

During a short visit to Cambridge, Everything Dinosaur team members were able to examine a specimen of the remarkable Wollemi pine (Wollemia nobilis). This tree is regarded as a “living fossil”.  However, its fossil record is extremely poor and scientists are uncertain of its phylogeny.  What is certain, is that this gymnosperm is exceptionally rare.

In 1994, a small grove of fewer than a hundred Wollemi pines were found in a deep gorge in the Blue Mountains (New South Wales). The location remains a secret as this sheltered area is the only known habitat for these remarkable trees. This amazing discovery sparked a global effort to study and conserve the Wollemi pine, which is now considered one of the rarest trees on the planet. Two Wollemi pines have been potted into large planters flanking the glasshouses at the Cambridge University Botanic Gardens. In addition, a third specimen is located close to another ancient type of tree, a Dawn Redwood.

A young Wollemi pine (Wollemia nobilis) at the Cambridge University Botanic Garden. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The Extremely Rare Wollemi Pine

Ironically, the Wollemi pine (Wollemia nobilis) is not a pine.  It is thought to be a member of the Araucariaceae, a family of coniferous trees with three living genera, Agathis, the Wollemi pine and the Araucaria (monkey puzzle tree).   These trees flourished during the Mesozoic. They had a global distribution, although these days they are mostly confined to the Southern Hemisphere.  Wollemia nobilis shares several characteristics with both Araucaria and Agathis. Genetic studies have proved controversial, as they lacked consistency of method. However, many palaeobotanists consider Wollemia nobilis as a sister taxon to Agathis within the Araucariaceae and therefore more closely related to Agathis than it is to Araucaria.

A piece of plant prehistoric history. A small Wollemi pine surrounded by ferns and horsetails. These are ancient plants representing taxa that evolved before flowering plants. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Models of Prehistoric Plants

For dinosaur model fans and collectors keen to build dioramas, there are not that many prehistoric plant models.  Safari Ltd used to include three prehistoric plant models within their range (Tree fern, Agathis and a Cycad). Sadly, all three of these figures have been retired.  Thankfully, diorama builders can rely on CollectA to provide models of prehistoric plants.  The company has introduced replicas of many prehistoric trees and plants.  For instance, CollectA have made a replica of Williamsonia, an example of a member of the Bennettitales Order of seed plants.

The CollectA Williamsonia prehistoric plant, a great addition to dinosaur dioramas.

To view the CollectA not-to-scale model range: CollectA Prehistoric Life Models.

Mike from Everything Dinosaur commented:

“It was fascinating to learn more about the remarkable Wollemi pine.  The Cambridge University Botanic Gardens are amazing.  We are so pleased that model makers and diorama builders still have the CollectA prehistoric plants to help them with their prehistoric landscapes.”

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

Newly published research suggests that large pterosaurs probably used all four limbs to propel themselves into the air, as seen in bats today.  Take-off is a vital part of powered flight.  The physical effort required to launch is dictated by body mass.  The bigger and heavier you are, the greater the physical effort required to take to the air.  This rule likely constrains the size of birds, yet extinct pterosaurs are known to have reached far larger sizes. How did pterosaurs launch?

The new study, published in the journal “PeerJ” suggest that large pterosaurs took off using a similar method as bats.  In essence, the researchers conclude that big flying reptiles used all four limbs to propel themselves into the air. This is referred to as “quadrupedal launching”.

The Mojo Fun Tropeognathus pterosaur model.  The researchers used a life-size computer-generated model of an ornithocheirid pterosaur such as Tropeognathus to conduct their research.

The picture above shows a typical ornithocheirid pterosaur (Tropeognathus). This is a model from the Mojo Fun prehistoric and extinct range.

To view this range of prehistoric animal figures: Mojo Fun Prehistoric Animal Models.

Quadrupedal Launching of Large Pterosaurs

This research helps scientists to understand the unique anatomy and biology of the Pterosauria.  In addition, it provides a new perspective on how flying reptiles became airborne, despite some taxa having wingspans in excess of ten metres. The scientific paper sheds new light on the flight initiating jumping ability of these archosaurs.

The research was conducted by scientists at the University of Bristol, the University of Keele, Liverpool John Moores University and Universidade Federal do ABC, São Bernardo do Campo, Brazil.  The team constructed a computer model of the skeleton and muscles of an ornithocheiraean pterosaur with a wingspan of five metres. Thirty-four key muscles were modelled to estimate limb movements through three alternative take-off motions.

The three alternative take-off motions:

• a vertical jump using just the hind legs, as seen in many ground-dwelling birds.
• a less vertical jump using just the legs, more similar to the jump used by birds that fly frequently.
• a four-limbed jump using the wings as well in a motion more akin to the take-off jump of a bat.

By reproducing these take-off motions using the large pterosaur model, the team were able to understand the forces generated to push the reptile into the air.

A replica of an ornithocheirid pterosaur based on Cambridge Greensand fossil remains. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The Bigger the Animal the Greater the Challenge of Becoming Airborne

Lead author of the study, Dr Ben Griffin (University of Bristol), explained:

“Larger animals have greater challenges to overcome in order to fly making the ability of animals as large as pterosaurs to do so especially fascinating. Unlike birds which mainly rely on their hindlimbs, our models indicate that pterosaurs were more likely to rely on all four of their limbs to propel themselves into the air.”

The researchers examined one of the long-standing questions about the underlying biomechanics of the Pterosauria. This study not only enhances the understanding of pterosaur biology but also provides broader insights into the limits and dynamics of flight in large vertebrates. By comparing pterosaurs with modern birds and bats, this research highlights the remarkable evolutionary solutions to the challenge of powered flight.

There are no living analogues for large pterosaurs. Hence, scientists rely on computer modelling to provide data on these remarkable creatures. After all, pterosaurs were the first vertebrates to evolve powered flight.

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

The scientific paper: “Modelling take-off moment arms in an ornithocheiraean pterosaur” by Benjamin W. Griffin​, Elizabeth Martin-Silverstone, Rodrigo V. Pêgas, Erik Anthony Meilak, Fabiana R. Costa, Colin Palmer and Emily J. Rayfield published in PeerJ.

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

Another week, and another new dinosaur.  This time, it is a tyrannosaur, and it has been named Asiatyrannus xui.  The fossils consist of a nearly complete skull and postcranial material. The postcranial material comprises leg bones and caudal vertebrae. A cross-sectional analysis of the right fibula has permitted the researchers to estimate the age of this tyrannosaur. It was at least thirteen years old when it met its demise.

Asiatyrannus co-existed with the much larger, Qianzhousaurus sinensis. Qianzhousaurus had a long, narrow snout.  When it was formally described in 2014 it was nicknamed “Pinocchio rex”.  The different skull morphologies and their different body sizes suggest that Asiatyrannus xui and Qianzhousaurus sinensis likely had different feeding strategies and occupied different ecological niches.  Asiatyrannus is the first deep-snouted tyrannosaurid to have been described from the Late Cretaceous of south-eastern China.

A skeletal reconstruction of the newly described (2024) deep-snouted Asian tyrannosaur (Asiatyrannus xui). Known fossil material in (A) shown in yellow. Photographs of the fossils (B-H). Picture credit: Zheng et al.

Picture credit: Zheng et al

Asiatyrannus xui

The fossil material was unearthed in September 2017 at a construction site in Shahe Town, Nankang District, Ganzhou City (Jiangxi Province).  The fossils were taken to the Zhejiang Museum of Natural History, Hangzhou, China for cleaning and preparation.  The genus name translates as “Asian tyrant king”, whilst the species name honours Dr Xing Xu (Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences).  Dr Xing Xu has made a huge contribution to the study of Chinese dinosaurs including research into and the naming of other tyrannosaurs (Dilong, Guanlong and Yutyrannus).

The discovery of Asiatyrannus highlights the diversification of deep-snouted tyrannosaurids towards the end of the Cretaceous.  It demonstrates that during the Late Cretaceous (Maastrichtian), different types of tyrannosaurs co-existed in south-eastern China.  Numerous dinosaurs are known from the strata in this area (Nanxiong Formation).  Ornithischians and sauropods have been described, but the majority of dinosaurs discovered are theropods, overwhelmingly oviraptorosaurs.

To read a blog post from 2016 about another oviraptorosaur from the Nanxiong Formation: Tongtianlong – A New Oviraptorosaur.

For an article describing a new oviraptorosaur (Corythoraptor) named in 2017: Another New Oviraptorosaur from Jiangxi Province.

Isolated teeth and other fragmentary elements suggest that there could have been other tyrannosaurid taxa present in this area at the very end of the Cretaceous.

Photograph (A) and line drawing (B) of the skull of Asiatyrannus xui (ZMNH M30360) in right lateral view. Picture credit: Zheng et al.

Picture credit: Zheng et al

Tyrannosaurid Growth Spurts

The open-access study published in “Scientific Reports”, includes details of bone histology.  This analysis revealed that this dinosaur died when it was a least thirteen years of age.  This is significant as the research team conclude that whilst this individual was not fully-grown, it had already passed through its most rapid growth phase.  Early tyrannosauroids such as Guanlong and Moros reached their adult size at around six to seven years of age.  In contrast, large-bodied tyrannosaurs from the Late Cretaceous (Campanian/Maastrichtian) such as Daspletosaurus, Tyrannosaurus rex and Albertosaurus had rapid growth spurts in their teenage years.  These theropods did not reach their full adult size until at least twenty years old.

Qianzhousaurus and Asiatyrannus xui

The skull of Asiatyrannus measures 47.5 cm in length.  Based on this, and the limb sizes, the research team estimate that Asiatyrannus had a body length of around 3.5 to 4 metres.  Qianzhousaurus (Q. sinensis) was over twice as big.  It had an estimated body length of around 9 metres.

These two carnivores very probably co-existed.  The long-snouted Qianzhousaurus was likely to have been the apex predator, with the smaller Asiatyrannus having the role of a secondary predator in the ecosystem.  Their different body sizes, and different shaped skulls suggest that these two dinosaurs may have had different hunting behaviours and perhaps, preyed on different animals.  They may not have directly competed, each tyrannosaur becoming adapted to a different ecological niche.  This could be an example of niche partitioning within coeval tyrannosaurids.

A size comparison between the probable, coeval tyrannosaurids Qianzhousaurus and Asiatyrannus. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The image above shows an approximate size comparison between the newly described Asiatyrannus xui and the probably coeval Qianzhousaurus sinensis.

Note: the models used to show the comparison are the PNSO Lythronax and Qianzhousaurus figures.

To view the PNSO range of prehistoric animal models: PNSO Dinosaur Models.

Implications for Mid-sized Theropod Carnivores

The paper’s authors comment that the discovery of Asiatyrannus might have implications for the way in which Mesozoic ecosystems are perceived.  Medium-sized carnivorous dinosaurs are relatively rare in the fossil record.  For example, in the Late Cretaceous carnivore guilds are monopolised by tyrannosaurids.  Adult, medium-sized predators are exceptionally rare.  Scientists have postulated that the “missing mid-sized” niches in the theropod guilds of Late Cretaceous Laramidia and Asia could be a consequence of these types of carnivores being outcompeted by juveniles and sub-adults of much larger taxa.

To read an article about a scientific paper that postulates the juveniles of apex predators out-competed mid-sized theropod carnivores: Why Are There So Few Medium-sized Carnivorous Dinosaurs?

The polar tyrannosaur Nanuqsaurus (N. hoglundi) was thought to be a mid-sized Late Cretaceous carnivore.  However, new fossil material from the Prince Creek Formation of Alaska suggests that it was comparable in size to the likes of Gorgosaurus and Daspletosaurus.  In the light of the continuing speculation as to the taxonomic validity of Nanotyrannus, the paper’s authors propose that Asiatyrannus xui currently represents the only definitive small to medium-sized member of the tyrannosaur family.

Everything Dinosaur acknowledges the assistance of the scientific paper in the compilation of this article. The paper is licensed under a Creative Commons Attribution 4.0 International License: The Creative Commons License.

The scientific paper: “The first deep-snouted tyrannosaur from Upper Cretaceous Ganzhou City of southeastern China” by Wenjie Zheng, Xingsheng Jin, Junfang Xie and Tianming Du published in Scientific Reports.

Research into a living fossil has provided scientists with a fresh perspective on animal evolution.  A new brachiopod study, involving the careful analysis of over a thousand genera, indicates these ancient creatures were diversifying and evolving but this did not result in many new species.  The research published in the journal “Nature Ecology & Evolution”, challenges some of the core principles of evolution.

Let’s hear it for the humble brachiopod!

What is a Brachiopod?

Brachiopods (Brachiopoda) are shelled animals that originated during the Cambrian.  Many resemble Roman oil lamps, hence their common name “lamp-shells”.  Their shells consist of two parts (valves), with one part larger than the other.  They are entirely marine and benthic.  These filter feeders have shells around two to five centimetres in diameter, although some genera grew much larger.  Although superficially similar to molluscs such as clams, mussels and oysters, they are not closely related.

Triassic brachiopod fossils (left), recent brachiopod shells (right). Picture credit: Zhen Guo.

Picture credit: Zhen Guo

In many species of brachiopod, the animal is attached to the sea floor by a fleshy stalk (pedicle).  The presence of a pedicle is indicated by the hole located on the larger of the valves (see picture above).  They were abundant in the Palaeozoic and Mesozoic and are often the most common fossil found in Palaeozoic marine deposits.  These ancient creatures are still around today but most species are confined to deep water.  Some 12,000 fossil species have been named.  In contrast, it has been estimated that there are less than 500 extant species.

Lots of brachiopod and coral fossils to find at Wren’s Nest.  The strata were deposited during the Silurian, a time when the Brachiopoda were abundant. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

New Brachiopod Study

This new brachiopod study is a collaboration between the University of Bristol, the China University of Geosciences and the Open University.  The team found that following the end-Permian mass extinction event, the Brachiopoda were evolving in new directions, but this did not lead to many new species.  In comparison, the Mollusca became increasingly dominant.  Today, the Mollusca is an amazingly diverse phylum with more than 50,000 species. The Brachiopoda currently contains just 394 known species.  The research team found that brachiopods were evolving new shell shapes and ecological behaviours following the end-Permian mass extinction, but their diversity did not grow.

Lead author Dr Zhen Guo (China University of Geosciences) explained:

“In the Palaeozoic, from 540 to 250 million years ago, brachiopods ruled the seabed.  Most of them are quite small–you could hold twenty of them in your hands; but others were big and thick-shelled and lived a long time. Their shells were anything from circular to widely stretched and they had either smooth shells or carried deep ridges and troughs.”

Professor Michael Benton (University of Bristol), a co-author of the new brachiopod study, commented:

“The brachiopods were hit very hard by the end-Permian mass extinction 252 million years ago.  The group could have disappeared completely, and indeed from that point, molluscs just became more and more successful. For a long time, it was thought that the brachiopods remained rare because the survivors were stuck in just a few modes of life.”

Studying Over 1,000 Brachiopod Genera

This new research involved the analysis of a vast brachiopod database.  More than 1,000 genera were studied.  This database was comprised of brachiopods that lived after the Permian.  For each genus, the analysts recorded dozens of measurements of the overall shape of the shells, their external sculpture, and internal anatomy. These features were analysed together to provide measurements of overall diversity of shapes for each major brachiopod group at each point in geological time. This measure of “diversity of shape”, is referred to in biology as “disparity”.  An understanding of shape innovations and changes over time could then be plotted.

These Mesozoic-Cenozoic brachiopods were adapting to different modes of life, but there were fewer species evolving than expected.

Reconstructions of some Mesozoic-Cenozoic brachiopods, showing adaptations to certain environments. Picture credit: Shunyi Shi.

Picture credit: Shunyi Shi

The co-author from the Open University, Dr Tom Stubbs added:

“In fact, the post-extinction brachiopods were innovating and trying new modes of life. One group, the terebratulids, were diversifying their body shapes and ecological functions from the end of the Permian to the present day, but their diversity did not increase.”

To read about an earlier, related brachiopod study conducted by University of Bristol researchers: Brachiopods and Bivalves (Mollusca) Faunal Turnover Study.

Unexpected Results

Fellow researcher Professor Zhong-Qiang Chen of the China University of Geosciences said:

“This was quite unexpected. Brachiopods were far from failures after the end-Permian extinction. They were evolving in new directions and exploring new modes of life, just as the molluscs were at the same time. But this did not turn into evolutionary success in terms of the numbers of species. Despite their bursts of evolution in form and function, they could not spread widely, and the exact reason remains unclear.”

Modern brachiopods represent the tip of the ecological iceberg for this once immensely abundant phylum.  Extant species do not provide scientists with an understanding of their extremely successful lineage, but we don’t know why these marine creatures did not become super-abundant again after the Permian.

Dr Zhen Guo explained the importance of this research.  This new brachiopod study suggests that disparity and diversity are effectively decoupled, at least as far as the Brachiopoda after the Permian are concerned.

Dr Zhen Guo concluded:

“It’s important to understand modern biodiversity in terms of the processes that lie behind it.”

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

The scientific paper: “Morphological innovation did not drive diversification in Mesozoic–Cenozoic brachiopods” by Zhen Guo, Michael J. Benton, Thomas L. Stubbs, and Zhong-Qiang Chen published in Nature Ecology & Evolution.

The Everything Dinosaur website: Prehistoric Animal Toys.

A research paper published this week in the journal “Nature” has revealed that early mammals may have lived much longer than their modern-day counterparts.  The study describes two Krusatodon kirtlingtonensis fossil specimens.  These mouse-sized mammals lived approximately 166 million years ago (Bathonian faunal stage of the Middle Jurassic).  The fossils come from the remarkable Jurassic strata found on the Isle of Skye.

The research led by National Museums Scotland describes the fossilised remains of one adult and one juvenile.  The adult K. kirtlingtonensis is thought to have been around seven years old when it perished.  The juvenile is thought to have been between seven to twenty-four months old when it died.  It was still in the process of replacing its deciduous dentition (milk teeth) with its final, adult set of teeth.

National Museums Scotland’s Dr Elsa Panciroli with enlarged, 3D printed models of Krusatodon kirtlingtonensis skeletons. Picture credit: Duncan Mc Glynn.

Picture credit: Duncan Mc Glynn

The scientists conclude that early diverging mammaliaforms did not experience the same life histories as extant small-bodied mammals. Furthermore, the fundamental shift to faster growth over a shorter lifespan may not have taken place in mammaliaforms until during or after the Middle Jurassic.

Two Krusatodon kirtlingtonensis Fossil Specimens

These two Krusatodon kirtlingtonensis fossils are extremely significant.  The adult specimen represents one of the earliest fossil discoveries from the Isle of Skye.  It was found in the 1970s.  This specimen is one of the most complete Jurassic mammaliaform skeletons known to science.  The juvenile fossil was found more recently (2016).  It is the only known skeleton of an immature Jurassic mammaliaform. Indeed, there is no other record of an adult and juvenile from the same Jurassic mammaliaform taxon.

The Isle of Skye is one of the most important locations in the world for Middle Jurassic fossils.  Vertebrate body and trace fossils confirm the presence of a rich biota of dinosaurs, pterosaurs and early mammals. This new study focusing on K. kirtlingtonensis underscores the significance of the Scottish island to palaeontology.

An article about the discovery of a large, new species of pterosaur (Dearc sgiathanach): Fantastic Pterosaur from the Isle of Skye.

Dr Elsa Panciroli examines the barnacle encrusted fossil which contained Krusatodon kirtlingtonensis material. Picture credit: Duncan Mc Glynn.

Picture credit: Duncan Mc Glynn

X-ray Computed Tomography Employed

The discovery of a juvenile and adult of the same species of Jurassic mammaliaform is unique.  As a result, a ground-breaking comparative analysis into their growth and life history (ontogeny) was undertaken. The ages of the specimens at death were determined using X-ray imaging to count the growth rings in their teeth.  Therefore, the age of each animal at the time they died could be established.  The X-ray computed tomography was carried out in several laboratories, including the European Synchrotron (ESRF) located in Grenoble, France.

Extant small mammals have much shorter lifespans.  Many live for less than a year.  They mature quickly, losing their milk teeth and weaning within months of birth.  In addition, most small mammals living today rapidly reach sexual maturity and breeding age. The Krusatodon fossils reveal for the first time that the earliest mammals didn’t finish replacing their milk teeth until well into their second year of life, possibly later.  The researchers conclude that mammals grew more slowly in the Jurassic than they do today.  This suggests a fundamental shift in the growth patterns and life expectancy of mammals must have taken place during or after the Middle Jurassic.

An adult and young Krusatodon kirtlingtonensis life reconstruction. A stegosaur can be seen in the background. Fossilised tracks found on the Isle of Skye indicate the presence of stegosaurs in the ecosystem.  Picture credit Maija Karala.

Picture credit: Maija Karala

Dr Elsa Panciroli, lead author and Associate Researcher of Palaeobiology at National Museums Scotland, commented:

“These fossils are among the most complete mammals from this time period in the world. They give us unprecedented insights into the lives of the first mammals in the time of dinosaurs. Although on the outside Krusatodon looked like a shrew or mouse, on the inside it was quite different; it grew more slowly and lived much longer than small mammals do today. As a result, it probably had quite a different physiology and life history as well. Skye’s fossils are really putting Scotland firmly on the map when it comes to understanding mammal evolution. This is just the tip of the iceberg in terms of what they can tell us.”

National Museums Scotland’s Dr Elsa Panciroli pointing out details on a high-resolution scan of the Krusatodon kirtlingtonensis fossils. Picture credit: Duncan Mc Glynn.

Picture credit: Duncan Mc Glynn

Analysis of Teeth Growth Patterns Yields Surprising Results

Co-author Dr Elis Newham, a Postdoctoral Research Associate at Queen Mary University of London explained:

“Our study benefited greatly from a new technique we developed using synchrotron X-ray technology. This allowed us to analyse growth patterns in the teeth of these fossils, much like counting tree rings. It was surprising to discover that Krusatodon, while showing a similar development pattern to modern mammals, grew much slower and lived longer. This research emphasises the value of studying juvenile fossils, and the X-ray cementochronology technique offers a powerful tool for unlocking these secrets from the past.”

Dr Stig Walsh, Senior Curator of Vertebrate Palaeobiology at National Museums Scotland and fellow co-author on the research, said:

“Even in the context of the amazing palaeontological finds on Skye in recent years, these fossils are remarkable. Mammal fossils of this age are exceptionally rare worldwide, and most are just single teeth found by sieving sediment. To find two such rare fossil skeletons of the same species at different growth stages has rewritten our understanding of the lives of the very earliest mammals. We’re thrilled they are both now part of Scotland’s National Collection, an important part of the global fossil record, and will be preserved for generations of researchers to come.”

National Museums Scotland’s Dr Elsa Panciroli examines two Krusatodon kirtlingtonensis fossils. Picture credit: Duncan Mc Glynn.

Picture credit: Duncan Mc Glynn

International Collaboration

In addition to National Museums Scotland, the study also involved researchers from the American Museum of Natural History (New York), the University of Chicago, the European Synchrotron Radiation Facility, and Queen Mary University of London.

Co-author Professor Roger Benson (American Museum of Natural History), described the juvenile fossil material:

“When we found the tiny juvenile skull, I didn’t realise what we’d found right away. The part of the fossil that was sticking out of the rock was blasted by erosion, surrounded by barnacles, and looked just like a piece of ash. I used micro-CT scanning, a form of 3D X-ray imaging, and was very surprised to see a whole skull in the rock. For science, it’s really remarkable to have this fossil and it told us a lot about growth and life history in some of the earliest mammals.”

To read a blog post from 2019 about greater legal protection for Scottish fossil sites: Legal Protection for Isle of Skye Fossils.

Everything Dinosaur acknowledges the assistance of a media release from National Museums Scotland in the compilation of this article.

The scientific paper: “Jurassic fossil juvenile reveals prolonged life history in early mammals” by Elsa Panciroli, Roger B. J. Benson, Vincent Fernandez, Nicholas C. Fraser, Matt Humpage, Zhe-Xi Luo, Elis Newham and Stig Walsh published in the journal Nature.

The Everything Dinosaur website: Prehistoric Animal Models and Toys.

And so, the hammer came down and bidding ended on a remarkable Stegosaurus fossil skeleton that had been offered for sale at the auction house Sotheby’s (New York).  The Stegosaurus specimen, nicknamed “Apex” sold for a whopping $44.6 million USD (£34.5 million GBP).  This is a world record amount for a dinosaur fossil.  It had an estimated value of between $4 million and $6 million USD.  However, as the bidding started this was soon exceeded.

Seven bidders wanted this Stegosaurus, and they were prepared to pay big bucks to get it.  After fifteen minutes of frantic excitement lot thirteen was sold.  Unsurprisingly, given the sums involved, the Stegosaurus fossil skeleton was purchased by an anonymous bidder.  The buyer is believed to be a billionaire hedge fund owner (Kenneth Griffin).

The stunning Stegosaurus skeleton “Apex” sold for a world record amount of $44.6 million USD at Sotheby’s New York. Picture credit: Matthew Sherman.

Picture credit: Matthew Sherman

“Apex” A Stunning Stegosaurus Fossil Skeleton

“Apex” was discovered on privately owned land in Moffat County, Colorado.  The land is owned by a commercial palaeontologist called Jason Cooper.  It is ironic, that the dig site was close to the small town of Dinosaur. The material, representing a single animal, consists of 254 fossil bones. This represents nearly eighty percent of the entire skeleton. The estimated number of bones in a Stegosaurus skeleton is 319, give or take the odd chevron.

Not only is it one of the most complete large dinosaur skeletons discovered, the bones bear witness to some remarkable pathology that helps tell the tale of this iconic Late Jurassic herbivore. The mounted skeleton measures over 8.2 metres long.

The impressive “thagomizer” on “Apex” the Stegosaurus fossil skeleton. Picture credit: Matthew Sherman.

Picture credit: Matthew Sherman

Auction House and Commercial Palaeontologist Co-operating Closely

Cassandra Hatton, Sotheby’s Global Head of Science & Popular Culture worked closely with Jason Cooper from the day of discovery onwards.  The fossils were carefully documented and excavated.  The material was prepared and mounted and at each stage the highest standards of transparency were adhered to.  The aim being to preserve as much information about the fossils as possible.  Skin impressions were noted and three, tiny ossicles representing throat armour were carefully extracted from the Morrison Formation matrix.  These also ended up as part of the Stegosaurus lot.

This is the first time an auction house has been so intimately involved with a dinosaur skeleton.

Cassandra stated:

“This sale has been years in the making, and at every turn, we have worked closely with Jason Cooper, from the moment of its discovery in Dinosaur, Colorado, to its sale in New York.  I am thrilled that such an important specimen has now taken its place in history, some 150 million years since it roamed the planet.  This remarkable result underscores our unwavering commitment to preserving these ancient treasures.”

Following the sale, the anonymous buyer is believed to have remarked:

“Apex was born in America and is going to stay in America!”

An Amazing Specimen

The fossil was preserved in hard sandstone and the black colour is typical of Morrison Formation specimens.  The fossils represent a fully-grown, robust adult and the fossilisation is described as “superb”, with little or no distortion.  Along with the skin impressions, fragile cervical plates and elements of the pebbly throat armour have been preserved.  Some fossil bones indicate the presence of arthritis.  This suggests “Apex” lived to an old age.  There are no signs of combat injuries or trauma on the bones.  In addition, there is no evidence of post-mortem scavenging by theropod dinosaurs.

A spokesperson from Everything Dinosaur commented that it was hoped that this remarkable Stegosaurus fossil skeleton would be made available to science for further study.

The spokesperson added:

“Commercial palaeontologists play an important role as they excavate specimens that could have been lost to science through erosion and weathering.  To excavate, clean and prepare such a remarkable specimen would have probably cost hundreds of thousands of dollars. Whilst we understand the importance of financial gain in these situations, and we suspect a portion of the money will be reinvested in further field work and research, hopefully, this specimen will be made available to the scientific community for further analysis and study.”

Sotheby’s Natural History Auction

The auction featured numerous amazing fossil specimens as well as meteorites, minerals, gogottes and for the first time, Palaeolithic tools including tools made by Neanderthals.  The Neanderthal tools sold for $22,800 USD, much higher than the pre-auction estimate.  A large iridescent ammonite fetched an eye-watering $72,000 USD.

Other fossils in the auction included mass mortality trilobite fossils from Morocco, Megalodon otodus teeth, fossil eurypterids from New York and beautiful fossilised fish. The natural history themed auction also featured meteorites and rare minerals including a large lapiz lazuli tower from Afghanistan.

The auction also included numerous dinosaur fossils such as a Tyrannosaurus rex femur, two T. rex teeth and an Edmontosaurus (E. annectens) skull.

Lot 26 the Edmontosaurus skull with an estimated value of between $40,000 and $60,000 USD. Picture credit: Sotheby’s New York.

Picture credit: Sotheby’s New York

Auctions of fossils and other rare objects can be controversial.  For example, Everything Dinosaur has previously reported upon the seizure of a Tarbosaurus specimen after evidence emerged that it had been illegally smuggled out of Mongolia.

To read more about this: Tyrannosaur Skeleton Smuggled out of Mongolia.

Sadly, there is a lot of illegal fossil collecting taking place. Many of these specimens are sold on the black market and find their way into Europe and America.  However, the authorities in many countries are cracking down on this illegal trade and some perpetrators have been jailed.

Fossil dealer incarcerated: American Fossil Dealer is Jailed.

The spokesperson from Everything Dinosaur commented:

“It is worrying to read of other rare items being offered for auction, particularly the Palaeolithic tools.  The large sums of money these lots are sold for could incentivise unscrupulous parties to exploit archaeological sites as well as fossil quarries.  Let us hope that sales such as this leads to closer regulation and greater co-operation between countries.”

Everything Dinosaur acknowledges the assistance of a media release from Sotheby’s New York “The most valuable fossil ever sold at auction “apex” achieves $44.6m at Sotheby’s”.  This media release was available to download from the Sotheby’s New York website on 18th July 2024.