Remarkable Arthropleura fossils from France offer new insights into the life and behaviour of one of the largest invertebrates known to science.  For the first time, scientists have revealed the head of this giant arthropod in detail.  Intriguingly, this study suggests that this Carboniferous creature had characteristics of both millipedes and centipedes.  Arthropleura was a giant arthropod.  For years, palaeontologists had only fragmentary body fossils to study.  It was thought that it was a giant millipede, probably herbivorous, but the absence of any fossil material representing the head had meant that scientists could not be certain about its taxonomy.

The CT analysis of a fossil preserving the head surprised the research team.  The head displays traits similar to early centipedes. This suggests that millipedes and centipedes may be more closely related than previously thought.

Arthropleura sp., specimen MNHN.F.SOT002123, details on the ventral sclerites and the feeding apparatus revealed by computer modelling after a CT scan of the fossil. Picture credit: Lhéritier et al.

Picture credit: Lhéritier et al

A Giant Invertebrate

Regarded as one of the largest land invertebrates of all time, some specimens may have measured over 2.6 metres in length. Arthropleura belongs to the arthropod group, which includes insects, crustaceans, and arachnids.  It had been thought that it preferred damp, swampy environments.  However, a study of fossil material published in 2021 indicated that larger individuals may have inhabited open woodland.

To read more about the giant invertebrate Arthropleura: Largest-ever Arthropleura Fossils Described.

An out-dated reconstruction of the giant arthropod Arthropleura.

The researchers, writing in the academic journal Science Advances, reveal breath-taking details identified from CT scans.  The fossils do not represent fully grown individuals.  However, they reveal important new details.  Notably, the head morphology is similar to that of early centipedes.

One of the authors of the paper, Dr Greg Edgecombe from the London Natural History Museum explained how these fossils helped refine our understanding of Arthropleura. He explained that previously, the presence of two pairs of legs on each body segment indicated affinity with millipedes.  Therefore, Arthropleura was thought to be a giant millipede.  However, now that fossil material representing the head has been studied, this theory has been challenged.  The head had enclosed mandibles and two pairs of head limbs behind them.  These fossils challenge long held views on millipede and centipede taxonomy.

By combining data from hundreds of genes in living species with physical characteristics of fossils like Arthropleura, the situation was clarified. Millipedes and centipedes are actually each other’s closest relatives.

Studying Arthropleura Fossils

Many aspects of Arthropleura’s life remain a mystery, such as how it breathed and what it ate. Researchers are gradually forming a clearer picture of this invertebrate.

Living between 346 and 290 million years ago, Arthropleura was the largest land invertebrate during an era of giant arthropods. When these animals died, sediment quickly buried them. Some became encased in a mineral called siderite, forming nodules. These fossils preserved even the most delicate anatomical features, making them valuable for researchers.

After hundreds of millions of years of continental drift, some siderite nodules surfaced in a coal mine in Montceau-les-Mines, France, during the 1970s. They later went to the Museum of Autun, where CT scans are finally revealing their hidden contents.

In the past, these nodules would have been split open and casts taken to produce three-dimensional replicas of the fossils.  However, the paper outlines how the Arthropleura fossils were scanned using a combination of microCT and synchrotron imagery to examine the Arthropleura inside, revealing the fine details of its anatomy.

A photograph of a latex cast taken from an Arthropleura fossil, the counterpart to specimen number MNHN.F.SOT002122. Picture credit: Lhéritier et al.

Picture credit: Lhéritier et al

Two Important Specimens

Two specimens were of particular significance to the researchers. These fossils represent juveniles. They measure just twenty-five and forty millimetres long, it is these fossils that reveal how Arthropleura reached a huge size.

Arthropleura specimens have different amounts of body segments. This suggests that these invertebrates added them until they reached a fixed maximum number. This is like most extant millipedes but differs from many centipedes, which are born with all of their segments already in place.

This means that Arthropleura’s maximum size would have been reached by, or after, sexual maturity, rather than at birth. The maximum size of the species used in the study is an open question, but it may not have been as massive as some of the biggest fossil specimens of Arthropleura spp. indicate.

It had been suggested that Arthropleura inhabited swampy environments. Whilst it was probably limited to equatorial regions, a recent study suggests it preferred open woodland. Picture credit: National Museum of Wales.

Picture credit: National Museum of Wales

Eyes on Stalks

Other aspects of their lifestyle are similarly ambiguous. While the researchers found that Arthropleura had club-shaped eyes, their structure has not survived. Moreover, startlingly, the Arthropleura fossils reveal that the eyes were on stalks. This is not a common feature in centipedes and millipedes. The team believe they were probably compound eyes, based on the animal’s relatives, but they cannot be certain.

No venom fangs or legs specialised for catching prey were found. Its legs are better adapted for slow movement. It is likely that Arthropleura was a detritus-eating animal, with a diet similar to modern day millipedes.

Everything Dinosaur acknowledges the assistance of the media team at the London Natural History Museum in the compilation of this article.

The scientific paper: “Head anatomy and phylogenomics show the Carboniferous giant Arthropleura belonged to a millipede-centipede group” by Mickaël Lhéritier, Gregory D. Edgecombe, Russell J. Garwood, Adrien Buisson, Alexis Gerbe, Nicolás Mongiardino Koch, Jean Vannier, Gilles Escarguel, Jérome Adrien, Vincent Fernandez, Aude Bergeret-Medina and Vincent Perrier published in Science Advances.

The Everything Dinosaur website: Prehistoric Animal Toys.

Remarkable cynodont fossils from southern Brazil are helping researchers from the University of Bristol and their South American colleagues to better understand mammal evolution.  The fossils represent the mammal-precursors Brasilodon quadrangularis and Riograndia guaibensis.  These animals lived in the Late Triassic.  The fossils provide a critical insight into the development of the mammalian middle ear and jaw.  These key anatomical features of the Mammalia may have evolved millions of years earlier than previously thought.

Getting to Grips with Mammal Evolution

Mammals have a distinctive jaw structure and have evolved three middle ear bones to help with hearing.  The evolutionary transition from earlier tetrapods which had a single middle ear bone, has intrigued palaeontologists.  This new research, published in the journal “Nature” examines how mammalian ancestors (cynodonts), evolved these features over time.

Computed tomography (CT scans) was used to create digital models of the jaw joint of these Brazilian cynodonts.  The scientists discovered a “mammalian-style” contact between the skull and the lower jaw in Riograndia guaibensis.  This feature was not found in the Brasilodon quadrangularis fossil material.   B. quadrangularis is closer to the stem mammals than Riograndia guaibensis. This discovery suggests that the defining mammalian jaw feature evolved multiple times in different groups of cynodonts.  In addition, Riograndia lived around seventeen million years earlier than the previous oldest known example of this structure.  This indicates that this anatomical feature had evolved earlier than previously thought.

Riograndia guaibensis and Brasilodon quadrangularis life reconstruction. Brasilodon quadrangularis (left) and Riograndia guaibensis (right). Picture credit: Jorge Blanco.

Picture credit: Jorge Blanco

Brazilian cynodont fossils have played an important role in helping to better understand mammal evolution. In 2022, Everything Dinosaur reported on an analysis of the teeth of Brasilodon quadrangularis that led palaeontologists to suggest the Mammaliaformes (the lineage leading to the modern Mammalia), originated some twenty million years earlier than previously perceived.

To read this article: Nibbling Away at the Earliest Date for True Mammals.

New Study Suggests Mammaliaformes Experimented with Different Jaw Functions

The authors of this new study conclude that Mammaliaformes experimented with different jaw functions, leading to the evolution of “mammalian” traits independently in various lineages.

Lead author of the study, James Rawson (University of Bristol) explained:

“The acquisition of the mammalian jaw contact was a key moment in mammal evolution. What these new Brazilian fossils have shown is that different cynodont groups were experimenting with various jaw joint types, and that some features once considered uniquely mammalian evolved numerous times in other lineages as well.”

This new research has significant implications for the understanding of the early stages of mammal evolution.  The study illustrates that features such as the mammalian jaw joint and middle ear bones evolved in a patchwork, or mosaic, fashion across different cynodont groups.

Fossils from Brazil Have Global Significance for Understanding Mammal Evolution

Co-author of the study, Dr Agustín Martinelli (Museo Argentino de Ciencias Natural, Buenos Aires) added:

“Over the last years, these tiny fossil species from Brazil have brought marvellous information that enrich our knowledge about the origin and evolution of mammalian features. We are just in the beginning and our multi-national collaborations will bring more news soon.”

The researchers are eager to investigate further the South American fossil record.  It has proven to be a rich source of new information on mammalian evolution.

Professor Marina Soares of the Museu Nacional, Brazil, exclaimed:

“Nowhere else in the world has such a diverse array of cynodont forms, closely related to the earliest mammals.”

By integrating these findings with the results from other studies, the scientists hope to deepen their understanding of how early jaw joints functioned and contributed to the development of the Mammalia.

James added:

“The study opens new doors for palaeontological research, as these fossils provide invaluable evidence of the complex and varied evolutionary experiments that ultimately gave rise to modern mammals.”

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

The scientific paper: “Brazilian fossils reveal homoplasy in the oldest mammalian jaw joint” by James Rawson et al published in Nature.

The Everything Dinosaur website: Dinosaur and Prehistoric Mammal Toys.

Following the publication of a scientific paper describing Coahuilasaurus lipani the Saurolophinae evolutionary tree has been updated.  Coahuilasaurus was named and described by Longrich et al. This new Mexican hadrosaur is known from the front end of a skull.  It 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 genus name is derived from the Coahuila State and the Greek “sauros” for lizard. The species name honours the Lipani Apache tribe of northern Mexico.

It had been thought that the fossil material represented a Kritosaurus. However, a more detailed analysis revealed unique traits which permitted the establishment of a new species of hadrosaur.

To read Everything Dinosaur’s blog post about Coahuilasaurus lipani: A New Duckbill Dinosaur from Northern Mexico.

The Saurolophinae Evolutionary Tree

The phylogeny of Coahuilasaurus. Evolutionary tree of the Saurolophinae, showing the relationships of Coahuilasaurus within the Kritosaurini. Picture credit: Longrich et al.

Picture credit: Longrich et al

The researchers performed two phylogenetic analyses. The information used was given different weights, and the two sets of results are different. However, the second analysis is better-resolved and is in line with the stratigraphy.

Both analyses recover three major subclades within the Kritosaurini tribe.

1. Coahuilasaurus lipani, Gryposaurus utahensis, Rhinorex condrupus, and Gryposaurus notabilis.
2. Naashoibitosaurus ostromi, Anasazisaurus horneri, and Kritosaurus navajovius.
3. Comprises the South American kritosaurins, the Austrokritosauria, as well as “Gryposaurus” alsatei.

The Wild Safari Prehistoric World Gryposaurus dinosaur model.

The image (above) shows the Gryposaurus model that was introduced by Safari Ltd in 2013. This figure has been retired.

To view the range of Wild Safari Prehistoric World figures in stock at Everything Dinosaur: Wild Safari Prehistoric World Figures.

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.

Visit the award-winning Everything Dinosaur website: Dinosaur Models.

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.