A remarkable and extensive series of dinosaur tracks have been uncovered by researchers from the Universities of Oxford and Birmingham.  The location (Dewars Farm Quarry) reveals a series of trackways that date back to the Middle Jurassic (Bathonian faunal stage).  The scientists have uncovered multiple, lengthy trackways that form part of a huge “dinosaur highway”.  The quarry floor is covered by hundreds of dinosaur footprints.

Theropod tracks have been recorded.  These have been tentatively assigned to Megalosaurus.  Some of these three-toed prints indicate the presence of nine-metre-long carnivorous dinosaurs.  Sauropod tracks have also been found.  The sauropod tracks have been tentatively assigned to Cetiosaurus.  Cetiosaurus was the first sauropod dinosaur to be scientifically described (Owen 1841).  Some of the tracks indicate the presence of sauropods around eighteen metres in length.

The Dewars Farm Quarry excavation work taking place in June 2024. Picture credit: the University of Birmingham.

Picture credit: the University of Birmingham

The Remarkable Dewars Farm Quarry Dinosaur Tracks

This remarkable trace fossil site will be featured in a BBC television programme (Digging for Britain).  It will be broadcast on BBC Two on January the 8th.  A new public exhibition entitled “Breaking Ground” will be opening shortly at the Oxford University Museum of Natural History (OUMNH).  This exhibition will highlight the importance of the research into these dinosaur trackways.

A trio of fieldworkers excavating a dinosaur track. Picture credit: Caroline Wood (University of Oxford).

Picture credit: Caroline Wood (University of Oxford)

The site records the tracks made by dinosaurs as they crossed a wide lagoon. These extraordinary trace fossils offer a window into the lives of Middle Jurassic dinosaurs.  A snapshot revealing details about their movements, interactions, and the tropical environment that they inhabited.

The excavations were carried out at the Dewars Farm Quarry (Oxfordshire).  Five extensive trackways were uncovered, although there are probably many more prints and tracks in this area.  The longest continuous trackway measures over one hundred and fifty metres in length.  Four of these trackways were made by sauropods.  The fifth set of prints were made by a theropod.

Sauropod track SE38 picture credit: Dr Luke Meade University of Birmingham.

Picture credit: Dr Luke Meade University of Birmingham

Theropod and Sauropod Tracks Interacting

One area of the quarry preserves theropod and sauropod tracks crossing over.  This raises intriguing questions about whether and how these two dinosaurs were interacting.

Intersection of theropod and sauropod tracks. The theropod track is (left) with the deeper and larger sauropod behind it (right). Picture credit: Dr Luke Meade University of Birmingham.

Picture credit: Dr Luke Meade University of Birmingham

Vertebrate palaeontologist Dr Emma Nicholls (OUMNH), commented:

“Scientists have known about and been studying Megalosaurus for longer than any other dinosaur on Earth, and yet these recent discoveries prove there is still new evidence of these animals out there, waiting to be found.”

The tracks were buried under mud and came to light when quarry worker Gary Johnson felt “unusual bumps” as he was stripping the clay back with an excavator in order to expose the quarry’s limestone floor.  When the significance of the discovery was confirmed, experts were invited to the site to explore and map the trace fossils.  The Universities of Oxford and Birmingham collaborated on this research project.  A team of more than a hundred people worked at the site on a week-long excavation in June 2024.  The scientists thanked the staff at Dewars Farm Quarry and Duns Tew Quarry for their help with this project.

An aerial view of the dinosaur track site taken on the 22nd June 2024. Picture credit: University of Birmingham.

Picture credit: University of Birmingham

Drone Photography and Three-dimensional Footprint Models

The week-long excavation revealed around two hundred dinosaur footprints.  The researchers used aerial drone photography to document the site and map the location of the tracks.  Computer modelling was employed to create sophisticated three-dimensional prints.  In addition, colour depth models of prints were made providing further insight into the tracks and the substrate.

A colour depth computerised image showing a theropod and sauropod track intersecting. Picture credit: Dr Luke Meade University of Birmingham.

Picture credit: Dr Luke Meade University of Birmingham

Professor of Micropalaeontology at the University of Birmingham, Kirsty Edgar explained:

“These footprints offer an extraordinary window into the lives of dinosaurs, revealing details about their movements, interactions, and the tropical environment they inhabited.”

The scientists acknowledged the assistance of Duns Tew Quarry Manager Mark Stanway and his staff.  They were invaluable in providing both local expertise and operating specialist equipment such as excavators and rock saws.

Oxfordshire Dinosaur Tracks

These are not the first dinosaur tracks to have been found in Oxfordshire.  They connect to discoveries made in the area in 1997, where previous limestone quarrying revealed more than forty sets of dinosaur footprints.  Some of these trackways are up to one hundred and eighty metres long.  At the time, these tracks provided new information on the type of dinosaurs living in the area during the Middle Jurassic.

The Ardley dinosaur tracks discovered in the 1990s. Picture credit: Professor Paul Barrett.

Picture credit: Professor Paul Barrett

The location was recognised as one of the most scientifically important dinosaur track sites in the world. It was subsequently designated a Site of Special Scientific Interest. However, the original site is largely no longer accessible and, since the findings predated the use of digital cameras and drones, there is limited photographic evidence. The newly discovered dinosaur tracks demonstrate the importance of this location. Even though the discoveries are separated by just thirty years, modern techniques and technology mean the prints can be recorded much more comprehensively than ever before.

Commenting on the importance of this research, Professor Richard Butler (University of Birmingham), stated:

“There is much more that we can learn from this site, which is an important part of our national Earth heritage. Our 3D models will allow researchers to continue to study and make accessible this fascinating piece of our past for generations to come.”

Documenting the Dinosaur Tracks

During the study, more than twenty thousand images of the dinosaur tracks were created. These images will provide a wealth of new data and can help provide answers to questions about dinosaur locomotion, velocity and how they interacted.

Dr Duncan Murdock, Earth Scientist at OUMNH, added:

“The preservation is so detailed that we can see how the mud was deformed as the dinosaur’s feet squelched in and out. Along with other fossils like burrows, shells and plants we can bring to life the muddy lagoon environment the dinosaurs walked through.”

An artist’s reconstruction of the Dewars Farm Quarry site 166 million years ago. A Megalosaurus follows an adult Cetiosaurus with a second sauropod in the background whilst pterosaurs soar overhead. Picture credit: Mark Witton.

Picture credit: Mark Witton

The excavation was funded by the Geologists’ Association, School of Geography, Earth and Environmental Sciences at the University of Birmingham, and the University of Birmingham Alumni Fund.

A replica of the first “dinosaur” to be scientifically described, the CollectA Megalosaurus in ambush figure. This dinosaur was named before the term “Dinosauria” had been coined. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The picture (above) shows a replica of a Megalosaurus (M. bucklandii).  This is a modern interpretation of this iconic theropod dinosaur.  It was introduced by CollectA in 2021, and the figure is part of the Age of Dinosaurs Popular range.

To view the range of CollectA Age of Dinosaurs Popular models in stock: CollectA Age of Dinosaurs Popular Figures.

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

The award-winning Everything Dinosaur website: Dinosaur Models.

Researchers have described a new dinosaur from fossils found in southwestern China.   The dinosaur has been named Archaeocursor asiaticus.  It is the oldest ornithischian (bird-hipped) dinosaur from Asia described to date.  Phylogenetic analysis suggests Archaeocursor also represents the earliest-diverging ornithischian known from Asia. This discovery extends the known presence of ornithischian dinosaurs in East Asia to the Pliensbachian or even late Sinemurian stages of the Early Jurassic.

Archaeocursor asiaticus the oldest ornithischian dinosaur from Asia described to date. A silhouette of the dinosaur providing a basic body shape and highlighting the position of the fossil femur (top left). Top right, close-up view of bone histology confirming a subadult specimen. Proposed phylogeny (bottom) and the close relationship with Eocursor parvus from South Africa. Image credit: Yao et al.

Picture credit: Yao et al

Archaeocursor asiaticus

The Early Jurassic ornithischian dinosaurs in Laurasia are dominated by armoured dinosaurs.  Other types of ornithischian are rare. Scientists from Yunnan University, the Chinese Academy of Sciences, the Southeast Sichuan Geological Team and the Chongqing Institute of Palaeontology examined a nearly complete left femur.  The fossil, specimen number L01-HY999, was found approximately two kilometres north of Chongqing Central Park in Yubei District, Chongqing Municipality.  The leg bone fossil comes from the Lower Jurassic Dongyuemiao Member of the Ziliujing Formation.

Osteohistological analysis of the bone indicates that it came from a young adult.  The animal would have been less than a metre in length.  The genus name is derived from the Latin words “archaeo”, “cursor” and “asiaticus” which translate as “old runner from Asia”.  The team conducted an in-depth phylogenetic analysis that placed A. asiaticus as the earliest-diverging ornithischian dinosaur yet discovered in Asia, albeit with weak support. Archaeocursor asiaticus is identified as an ornithischian dinosaur based on distinctive morphological features, namely a broad, wing-like anterior trochanter and a well-developed flange-like fourth trochanter, which differentiate it within Ornithischia.

Related to Eocursor parvus from South Africa

Ornithischian fossils are scarce in Early Jurassic deposits of Asia, primarily reported from the contemporaneous Lower Jurassic Lufeng and Fengjiahe formations in Yunnan province, also in
southwestern China.  The phylogenetic analysis indicated that Archaeocursor asiaticus was closely related to Eocursor parvus. Eocursor is a genus of basal ornithischian dinosaur that lived in South Africa in the Early Jurassic. Its fossils had been thought to be much older dating from the Late Triassic (Norian). However, it is not possible at this time to determine the age of this fossil material with confidence. Many palaeontologists consider Eocursor to have lived during the Sinemurian (Early Jurassic).

To read an article from 2007 about the discovery of E. parvus: The Ancestor of Stegosaurus, Triceratops etc.

Ornithischian dinosaurs originated from Gondwana and migrated to the North Hemisphere in the Early Jurassic. However, the timing of their arrival in East Asia is obscure. The close relationship between Archaeocursor asiaticus and Eocursor parvus, despite their distance (China and South Africa respectively), suggests a probable ornithischian origin in Gondwana. At some point there followed a northward migration to Laurasia and eventually to East Asia during the Pliensbachian. This timing might precede the arrival of armoured dinosaurs in the region.

Everything Dinosaur acknowledges the assistance of the corresponding author of the scientific paper Xi Yao in the compilation of this article.

The scientific paper: “New evidence for the earliest ornithischian dinosaurs from Asia” by Xi Yao, Qi Zhao, Tingcong Ren, Guangbiao Wei and Xing Xu published in iScience.

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

A study of theropod teeth found in sediments from the Wadhurst Clay Formation suggests tyrannosaurs roamed the Bexhill-on-Sea region of East Sussex around 135 million years ago.  The research, published earlier this month in the journal “Papers in Palaeontology” highlights a community of theropods with many different families represented.  In addition to the tyrannosaurs, there were large spinosaurids and also dromaeosaurids present.

An Early Cretaceous floodplain around 135 million years ago. A large spinosaurid chases off some tyrannosaurs (left) from the carcass of an ornithopod. Dromaeosaurids (bottom right) dart in to snatch what they can as the larger theropods are preoccupied. Picture credit: Anthony Hutchings

Picture credit: Anthony Hutchings

Wadhurst Clay Formation

The Wadhurst Clay Formation is part of the Hastings Group, which in turn is a component of the Wealden Supergroup.  These Lower Cretaceous sediments have a rich diversity of theropod dinosaurs.  Fragmentary remains predominate, however, some of the most significant theropod fossils in the whole of Europe have been found in these rocks. Taxa include spinosaurids, neovenatorid allosauroids, tyrannosauroids, and dromaeosaurids.  It is noted that most specimens come from the younger Barremian Upper Weald Clay and Wessex formations.  The theropod diversity of the older Berriasian–Valanginian Hastings Group remains poorly understood.  For example, fragmentary specimens identified so far pose challenges in terms of their phylogenetic relationships and origins.

Berriasian–Valanginian dinosaur fossils are globally scarce.  Any insights gleaned from studying the Lower Cretaceous exposures representing Berriasian–Valanginian deposits is welcomed.

The research team examined an assemblage of theropod teeth from the Valanginian Wadhurst Clay Formation.  Most of the teeth coming from the Ashdown Brickworks site near Bexhill, East Sussex.  Dave Brockhurst, a retired quarryman has spent the last thirty years uncovering fossils from the Ashdown Brickworks.  His discoveries have been crucial in helping to better understand the theropod biota of the Wadhurst Clay Formation.

Retired quarryman Dave Brockhurst who has spent the last thirty years uncovering fossils from the Ashdown Brickworks.

Picture credit: University of Southampton

Theropod Dinosaur Fossils are Rare

Dr Chris Barker, visiting researcher at the University of Southampton and lead author of the study explained:

“Meat-eating dinosaurs, properly called theropods are rare in the Cretaceous sediments of southern England.  Usually, Isle of Wight dinosaurs attract most of our attention. Much less is known about the older Cretaceous specimens recovered from sites on the mainland.”

For example to read about the discovery to two new spinosaurs from fossils found on the Isle of Wight: Two New Spinosaurids from the Isle of Wight.

It’s the first time tyrannosaurs have been identified in sediments of this age and region.  The new Bexhill-on-Sea dinosaurs are represented by teeth, no other body or trace fossils have been found. Fortunately, theropod teeth are complex.  They vary in size, morphology and their denticles (serrated edges) can be diagnostic.  The researchers used several different techniques to analyse the theropod teeth including phylogenetic analysis along with discriminant and machine learning methods.

Dr Barker added:

“Dinosaur teeth are tough fossils and are usually preserved more frequently than bone. For that reason, they’re often crucial when we want to reconstruct the diversity of an ecosystem. Rigorous methods exist that can help identify teeth with high accuracy. Our results suggest the presence of spinosaurs, mid-sized tyrannosaurs and tiny dromaeosaurs – Velociraptor-like theropods – in these deposits.”

CT scan of the one of the theropod teeth. Picture credit: University of Southampton.

Picture credit: University of Southampton

Tyrannosaurs from the Wadhurst Clay Formation

The discovery of teeth that likely came from tyrannosaurs (tyrannosauroids) is particularly notable.  These theropods had not previously been identified in these sediments.  They would have been about thirty percent the size of the famous Tyrannosaurus rex of the Late Cretaceous.  They probably filled a secondary predator niche in the Wadhurst Clay Formation ecosystem.

Co-author Lucy Handford, a former University of Southampton Master’s student, who is now undertaking a PhD at the University of York, commented:

“Assigning isolated teeth to theropod groups can be challenging, especially as many features evolve independently amongst different lineages. This is why we employed various methods to help refine our findings, leading to more confident classifications. It’s highly likely that reassessment of theropod teeth in museum stores elsewhere will bring up additional discoveries.”

Intriguingly, the study identified representatives of Spinosauridae, Tyrannosauroidea, and Dromaeosauridae, along with some specimens of uncertain classification within Coelurosauria. Notably, these taxa differ from those previously identified in the Wealden Supergroup.  For instance, the spinosaurid cannot be linked to Baryonyx, nor can the tyrannosauroid be associated with Eotyrannus. Although the researchers did not designate any new taxa, their findings, in conjunction with other research from the Wadhurst Clay Formation, suggest that theropod diversity during the Valanginian was on a par with that of later Wealden Supergroup formations. This indicates that the distinctive theropod components of Wealden faunas were established early in this well-known geological sequence.

Discovered theropod teeth of (a) spinosaur, (b) tyrannosaur, (c) dromaeosaur, (d) possible tyrannosaur, (e) indeterminate tyrannoraptoran – the group containing tyrannosaurs and dromaeosaurs (Velociraptor and their kin). Note scale bar equals 1 cm. Picture credit Barker et al.

Picture credit: Barker et al

Providing a Unique Perspective on Early Cretaceous European Theropods

Dr Darren Naish (University of Southampton), a co-author of the study added:

“Southern England has an exceptionally good record of Cretaceous dinosaurs, and various sediment layers here are globally unique in terms of geological age and the fossils they contain. These East Sussex dinosaurs are older than those from the better-known Cretaceous sediments of the Isle of Wight, and are mysterious and poorly known by comparison. We’ve hoped for decades to find out which theropod groups lived here, so the conclusions of our new study are really exciting.”

The research project was supervised by Dr Neil Gostling (University of Southampton).  He explained that this study highlights the importance of museum collections, curators and local fossil collectors in developing our understanding of the Dinosauria.  The scientists acknowledged the assistance of the owners of the Ashdown Brickworks for their co-operation in this project.

Dr Neil Gostling stated:

“Two hundred years after the naming of the first dinosaur, Megalosaurus, there are still really big discoveries to be made.  Dinosaur palaeobiology is alive and well.”

The research was funded by the University of Southampton’s Institute for Life Sciences.

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

The scientific paper: “Theropod dinosaur diversity of the lower English Wealden: analysis of a tooth-based fauna from the Wadhurst Clay Formation (Lower Cretaceous: Valanginian) via phylogenetic, discriminant and machine learning methods” by Chris T. Barker, Lucy Handford, Darren Naish, Simon Wills, Christophe Hendrickx, Phil Hadland, Dave Brockhurst and Neil J. Gostling published in Papers in Palaeontology.

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

Artificial Intelligence (AI) is changing palaeontology. For example, researchers have used AI to determine the impact of hominin evolution on prehistoric elephants. The complicated AI-driven statistical analysis revealed that proboscidean extinction rates increased when humans arrived. The research published earlier this year in the academic journal “Science Advances” indicates that humans were responsible for proboscidean species extinction rates increasing.

Researchers from the University of Fribourg (Switzerland) in collaboration with a colleague from the Museo Nacional de Ciencias Naturales (Madrid, Spain) carried out the study. The research suggests humans increased extinction rates of prehistoric elephants over the last 1.8 million years.  AI was used to conduct a detailed Bayesian analysis.  They examined nearly two million years of data on proboscidean species.

Prehistoric elephants on display at the Senckenberg Museum (Frankfurt). The order Proboscidea was once extremely diverse. Over 180 fossil species have been described.  Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Human Evolution Resulted in the Extinction of Many Prehistoric Elephants

Previous studies linked climate change as well as human hunting to the extinction of iconic species such as the Woolly Mammoth and the American Mastodon. This research suggests human evolution caused the extinction of around 30 trunked species. Understanding extinction factors is challenging, especially for ancient species. Multiple factors often contribute, like environmental changes, physiological shifts, or new predators.

Most studies focus on a single factor. To address this, the researchers used a neural network-based AI system. This system assessed extinction using many factors in a complex Bayesian statistical analysis.

The team entered data for 2,118 proboscidean species from the last 35 million years. They included 17 factors that could affect survival chances. These factors included the arrival of early humans 1.8 million years ago and modern humans 129,000 years ago. The AI system identified humans as the main factor raising extinction rates. This impact started soon after humans appeared. Rates accelerated after the rise of modern humans. Today, only three elephant species remain.

The extant elephant species are:

• African Savanna Elephant (Loxodonta africana): The largest species, found in various habitats across sub-Saharan Africa.
• Asian Elephant (Elephas maximus): Found in various parts of Asia, including India and Southeast Asia, it is smaller than the African elephants.
• African Forest Elephant (Loxodonta cyclotis): Smaller than the savanna elephant, it inhabits the forests of central and west Africa.

The scientific paper: “Trait-mediated speciation and human-driven extinctions in proboscideans revealed by unsupervised Bayesian neural networks” by Torsten Hauffe, Juan L. Cantalapiedra and Daniele Silvestro published in Science Advances.

The Everything Dinosaur website: Models of Prehistoric Animals.

Staff from the Philip J. Currie Museum (Wembley, Alberta, Canada) have safely removed a massive Pachyrhinosaurus lakustai fossil skull from the Pipestone Creek Bonebed.  The specimen nicknamed “Big Sam” is estimated to weigh around two hundred and seventy kilograms (six hundred pounds).  The famous Pipestone Creek site is one of the densest dinosaur fossil deposits known.  The remains of hundreds of horned dinosaurs (P. lakustai) have been excavated.  Parts of the site have around three hundred individual fossils per square metre. “Big Sam” is the first complete skull to have been found at the site for more than a decade,

“Big Sam” the Pachyrhinosaurus lakustai skull wrapped in plaster and burlap. Picture credit: Philip J. Currie Dinosaur Museum.

Picture credit: The Philip J. Currie Dinosaur Museum

The Pipestone Creek Bonebed

The Pipestone Creek bonebed deposits constitute part of the Wapiti Formation. These strata were laid down during the Late Cretaceous.  This remarkable site has yielded an exceptional fauna dominated by abundant remains of the centrosaurine ceratopsian Pachyrhinosaurus.  However, Lambeosaurus and Edmontosaurus along with ankylosaurs and theropods have also been recorded from the Wapiti Formation.  The Pachyrhinosaurus skull measures over a metre in length.  It is one of the largest ceratopsid skulls to have been found in northern Alberta.

Digging away at the underlying sediment to prepare “Big Sam” for flipping prior to extraction. Picture credit: Philip J. Currie Dinosaur Museum.

Picture credit: The Philip J. Currie Dinosaur Museum

The fossil skull is preserved upside-down and with its head frill still attached, a preservation event that has not previously been documented.  A field team from the Phillip J. Currie Museum have spent the last two summers meticulously mapping, excavating and jacketing the skull ready for transporting away from the quarry.

Inspecting the underside of the Pachyrhinosaurus lakustai skull jacket as “Big Sam” is prepared for transport. Picture credit: Philip J. Currie Dinosaur Museum.

Picture credit: The Philip J. Currie Dinosaur Museum

Pachyrhinosaurus lakustai

Pachyrhinosaurus lakustai is one of three Pachyrhinosaurus species that have been named. It is the geologically oldest species, having lived around 73 million years ago (Campanian stage of the Late Cretaceous). This species was formally named and described in 2008 (Currie, Langston and Tanke).

Pachyrhinosaurus was a smaller, older cousin of the Triceratops, with a big, bony protrusion on its nose instead of a nose horn.

The Haolonggood Pachyrhinosaurus dinosaur model (LvFang) photographed in the studio. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Dr Emily Bamforth, the curator at the Philip J. Currie Museum commented in an email sent to Everything Dinosaur:

“We were very excited to finally have ‘Big Sam’, the skull of a Pachyrhinosaurus lakustai we recently collect from the Pipestone Creek Bonebed, safe in our lab! I noticed that you do carry two models of P. lakustai, which is awesome. We actually use the Haolonggood Pachyrhinosaurus and Edmontosaurus for our outreach and education programmes here.”

To view the range of Haolonggood prehistoric animal figures in stock: Haolonggood Dinosaur Models.

Extracting the Fossil Skull

Once the three hundred or so other bones had been carefully removed from the surrounding area, the Museum team began the process of turning the jacketed fossil over and securing it ready for its journey away from the dig site.

“Big Sam” is carefully winched onto a trolley for transport away from the quarry. Picture credit: Philip J. Currie Dinosaur Museum.

Picture credit: The Philip J. Currie Dinosaur Museum

The huge block was slowly but surely winched up onto a trolley so that staff and volunteers could take this important fossil discovery to the preparation laboratory at the museum.  Laboratory technicians will then begin the laborious process of removing the fossil bones from the matrix allowing “Big Sam” to be seen in its glory.

Team members carefully escort the Pachyrhinosaurus skull fossil away from the quarry. The fossil will spend many months in the preparation lab being cleaned and prepared. Picture credit: Philip J. Currie Dinosaur Museum.

Picture credit: The Philip J. Currie Dinosaur Museum

Members of the public can visit and see the skull undergoing cleaning and preparation.  The objective is to eventually put this remarkable fossil specimen on display.

Everything Dinosaur acknowledges the assistance of a media release from the Philip J. Currie Dinosaur Museum in the compilation of this article.

The largest stem tetrapod known to have digits has been scientifically described. Named Gaiasia jennyae it lurked in the chilly waters of a Namibian swamp around 280 million years ago (Cisuralian Epoch of the Early Permian). Its discovery indicates a more global distribution of continental stem tetrapods during the Carboniferous-Permian transition.  Although no complete skeleton is known, G. jennyae was probably more than two metres in length.  The skull measures around sixty centimetres long.  It was probably an ambush predator, relying on suction capture to grab and swallow any prey item unfortunate to swim too close.  Once in the mouth, there was no escape as the jaws were lined with large fangs.

Gaiasia jennyae life reconstruction. A newly described stem tetrapod from a high palaeolatitude (approximately fifty-five degrees south). Picture credit: Gabriel Lio.

Picture credit: Gabriel Lio

Gaiasia jennyae Honouring the Late Professor Jenny Clack

Writing in the journal “Nature”, the scientists describe Gaiasia as a stem tetrapod, one from a high palaeolatitude (approximately fifty-five degrees south).  This is a significant fossil discovery, most other stem tetrapods from the Early Permian are known from palaeoequatorial regions.  The genus name is derived from the Gai-As Formation of Namibia.  The species name honours the late Professor Jenny Clack (1947–2020), in recognition for her ground-breaking work studying early tetrapods.

Tetrapods are four-limbed vertebrates (amphibians, reptiles, mammals and birds), that evolved from lobe finned fishes (Sarcopterygii).

To read an article from 2013, highlighting the work of Professor Jenny Clack on Ichthyostega: Ichthyostega Gets a Makeover.

Co-lead author of the study, Jason Pardo (NSF postdoctoral fellow at the Field Museum in Chicago) commented:

“Gaiasia jennyae was considerably larger than a person, and it probably hung out near the bottom of swamps and lakes. It’s got a big, flat, toilet seat shaped head, which allows it to open its mouth and suck in prey. It has these huge fangs, the whole front of the mouth is just giant teeth.  It’s a big predator, but potentially also a relatively slow ambush predator.”

A photograph of some of the prepared Gaiasia jennyae fossil material. Picture credit C. Marsicano

Picture credit: C. Marsicano.

Interlocking Large Fangs

The presence of such a large predator in the environment indicates that there was a rich and diverse ecosystem present.  Palaeontologists are aware that in the equatorial regions of Pangaea new four-limbed vertebrates (Tetrapodomorpha) were evolving.  However, in higher palaeolatitudes more ancient creatures persisted.

Co-lead author of the research Claudia Marsicano (University of Buenos Aires) explained:

“When we found this enormous specimen just lying on the outcrop as a giant concretion, it was really shocking. I knew just from seeing it that it was something completely different. We were all very excited.  After examining the skull, the structure of the front of the skull caught my attention. It was the only clearly visible part at that time, and it showed very unusually interlocking large fangs, creating a unique bite for early tetrapods.”

Several specimens were discovered, including one with a well-preserved, articulated skull and spine.  Although there might be a bias in fossil preservation, the number of individuals found suggests that Gaiasia jennyae was relatively common in the ancient Namibian cold-water swamp habitat.

Gaiasia jennyae fossil excavation in the Namibian desert. Claudia Marsicano examining nodules containing fossil bones. Picture credit: Roger M. H. Smith.

Picture credit: Roger M. H. Smith

Applying Bergmann’s Rule

With several specimens to study, the team were able to conduct an in-depth phylogenetic analysis.  The analysis indicates that Gaiasia might be related to other early tetrapods that became extinct around forty million years earlier.  This suggests that in highly palaeolatitudes “relic” taxa could still be found.

Namibia today, is located much further north than it was approximately 280 million years ago.  During the Cisuralian Epoch of the Early Permian, this area was a cold-water swamp.  At this time in Earth’s history, a global Ice Age was drawing to a close.  Equatorial regions were drying up and becoming more forested, but closer to the poles, swampy habitats persisted, potentially alongside patches of ice and glaciers.

The Biggest Suction-feeding Tetrapod from the Palaeozoic

As the largest Palaeozoic suction-feeding tetrapod known to science, it is also possible that Gaiasia may reflect thermophysiological constraints associated with cold-temperate climates in alignment with Bergmann’s rule.  Bergmann’s rule states that organisms in cold environments tend to be larger than their counterparts in warmer regions.  Larger organisms tend to be better at conserving heat.

Jason Pardo stated:

“Gaiasia is a stem tetrapod. It is a holdover from that earlier group, before they evolved and split into the groups that would become mammals, birds, reptiles and amphibians, which are called crown tetrapods. It’s really, really surprising that Gaiasia is so archaic. It was related to organisms that went extinct probably 40 million years prior.”

Intriguingly, for a relic of an older lineage, Gaiasia is doing more than just holding its own.

Pardo added:

“There are some other more archaic animals still hanging on 300 million years ago, but they were rare, they were small, and they were doing their own thing.  Gaiasia is big, and it is abundant, and it seems to be the primary predator in its ecosystem.”

Everything Dinosaur acknowledges the assistance of a media release from the Field Museum in Chicago in the compilation of this article.

The scientific paper: “Giant stem tetrapod was apex predator in Gondwanan late Palaeozoic ice age” by Claudia A. Marsicano, Jason D. Pardo, Roger M. H. Smith, Adriana C. Mancuso, Leandro C. Gaetano and Helke Mocke published in Nature.

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

A remarkable new taxon of ceratopsian has been described from northern Montana.  This new horned dinosaur, a centrosaurine, has been named Lokiceratops rangiformis.  The authors of the scientific paper, published in the journal PeerJ, suggest that the large number of similar taxa identified from this region suggests that dinosaur diversity has been underestimated.  In addition, mounting evidence indicates dinosaurs were living and evolving in a small geographic area (high endemism).  This high endemism identified in centrosaurines contrasts with the extensive (historic) ranges seen in most large mammals today.

Reconstruction of Lokiceratops surprised by a crocodilian in the 78-million-year-old swamps of northern Montana, USA. Picture credit: Andrey Atuchin for the Museum of Evolution in Maribo, Denmark.

Picture credit: Andrey Atuchin.

Lokiceratops rangiformis

The fossils were collected from the lower portion of the McClelland Ferry Member of the Judith River Formation in the Kennedy Coulee region close to the Canadian border. The fossil material consists of most of the skull, although the lower jaws were not found.  Postcranial material includes the right scapula and coracoid plus some vertebrae and elements from the hips.

Lokiceratops is one of the largest centrosaurines known to science.  It had an estimated body length of around 6.7 metres and is thought to have weighed 5 tonnes.  As well as being one of the largest members of the Centrosaurinae described to date, it is also one of the most ornate.  Lokiceratops possessed two, huge blade-like horns on the back of its frill (epiparietal 2).  The super-sized epiparietal 2 horns are relatively larger than any other parietal epiossification within the Centrosaurinae.

Lokiceratops had two large brow horns, but unlike most of its close relatives it lacked a nose horn. The frill ornamentations of Lokiceratops demonstrate bilateral asymmetry.  There is considerable variation in the shape of the seven epiparietals on the left and right sides of the frill.

The stunning frill and horns of Lokiceratops rangiformis. Picture credit: Fabrizio Lavezzi © Evolutionsmuseet, Knuthenborg.

Picture credit: Fabrizio Lavezzi © Evolutionsmuseet, Knuthenborg.

What’s in a Name?

The bilateral asymmetry gave rise to the species name.  The genus is named after the blade-wielding Norse god Loki, a god that causes chaos and mischief in Norse mythology.  The genus name translates as “Loki’s horned face”.  Whereas the species epithet comes from the reindeer/caribou genus Rangifer. This is a reference to the differing horn lengths on each side of the frill, similar to the asymmetric antlers of caribou and reindeer.

Co-author of the study Joseph Sertich, a palaeontologist with the Smithsonian Tropical Research Institute and Colorado State University stated:

“This new dinosaur pushes the envelope on bizarre ceratopsian headgear, sporting the largest frill horns ever seen in a ceratopsian.  These skull ornaments are one of the keys to unlocking horned dinosaur diversity and demonstrate that evolutionary selection for showy displays contributed to the dizzying richness of Cretaceous ecosystems.”

Portrait reconstruction of Lokiceratops rangiformis. Picture credit: Andrey Atuchin for the Museum of Evolution in Maribo, Denmark.

Picture credit: Andrey Atuchin

High Endemism in Centrosaurines

Lokiceratops rangiformis fossils come from the same narrow stratigraphic interval and geographic area as three other centrosaurines (Wendiceratops pinhornensis, Albertaceratops nesmoi, and Medusaceratops lokii) and one chasmosaurine (Judiceratops tigris). Phylogenetic analysis indicates that Lokiceratops is closely related to Wendiceratops and Albertaceratops.  Indeed, it has been placed in the tribe Albertaceratopsini along with Albertaceratops and Medusaceratops.

To read Everything Dinosaur’s blog post from 2010 about the scientific description of Medusaceratops lokii: A New Horned Dinosaur from Montana.

The research team concludes that the Albertaceratopsini, was one of multiple centrosaurine clades to undergo geographically restricted radiations, with Nasutuceratopsini restricted to the south and Centrosaurini and Pachyrostra restricted to the north.

Whilst ceratopsian ancestors were widespread across the Northern Hemisphere throughout the Cretaceous, their isolation on Laramidia led to the evolution of huge body sizes, and most characteristically, distinctive patterns of horns above their eyes and noses, on their cheeks and along the edges of their elongated head frills. Yet, based on current evidence and acknowledging uneven temporal and geographic sampling, all known centrosaurine species exhibit relatively small geographic ranges.

This pattern is seen not only in genera and species, but also above the species level. That is, centrosaurine subclades—including Albertaceratopsini—also show restricted geographic distributions.  Fossils recovered from this region suggest horned dinosaurs were living and evolving in a small geographic area, a high level of endemism that implies dinosaur diversity is underestimated.

Co-author Mark Loewen (Natural History Museum of Utah) explained:

“Previously, palaeontologists thought a maximum of two species of horned dinosaurs could coexist at the same place and time. Incredibly, we have identified five living together at the same time.  The skull of Lokiceratops rangiformis is dramatically different from the other four animals it lived alongside.”

Reconstruction of Lokiceratops in the 78-million-year-old swamps of northern Montana, USA as two Probrachylophosaurus move past in the background. Picture credit: Fabrizio Lavezzi © Evolutionsmuseet, Knuthenborg.

Picture credit: Fabrizio Lavezzi © Evolutionsmuseet, Knuthenborg.

Fossils Discovered in 2019

The fossils represent a mature, adult animal.  The material is found in the late spring of 2019 by Mark Eatman on private land of the Wolery Ranch in Kennedy Coulee.  It was excavated under a lease in the autumn.  The holotype specimen number is EMK 0012.  The individual fossilised skull bones of Lokiceratops were integrated into a state-of-the-art reconstruction of the complete skull and is permanently reposited and displayed at the Museum of Evolution in Maribo, Denmark.  A reconstruction of the skull, alongside a full-sized sculpture, will be displayed at the Natural History Museum of Utah in Salt Lake City for the next few months.

Lokiceratops rangiformis lived around 78 million years ago (Campanian faunal stage of the Late Cretaceous).

Andrew Farke from the Raymond M. Alf Museum of Paleontology and another co-author of the paper commented:

“We now recognise over thirty species of centrosaurines within the greater group of horned dinosaurs, with more like Lokiceratops being described every year”.  

Ceratopsians were much more diverse than previously thought.  This new research also demonstrates some groups such as the Albertaceratopsini had relatively small distributions across the island landmass of Laramidia.  Centrosaurine dinosaurs demonstrate geographically restricted radiations.  High speciation rates may have been driven in part by sexual selection or as a result of regional variations in climate or flora. The high endemism seen in centrosaurines and other dinosaurs implies that dinosaur diversity is presently underestimated and contrasts with the large (historic) geographic ranges seen in most extant mammalian megafauna.

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

The scientific paper: “Lokiceratops rangiformis gen. et sp. nov. (Ceratopsidae: Centrosaurinae) from the Campanian Judith River Formation of Montana reveals rapid regional radiations and extreme endemism within centrosaurine dinosaurs” by Mark A. Loewen​​, Joseph J. W. Sertich​, Scott Sampson, Jingmai K. O’Connor, Savhannah Carpenter, Brock Sisson, Anna Øhlenschlæger, Andrew A. Farke, Peter J. Makovicky, Nick Longrich and David C. Evans published in PeerJ.

The Everything Dinosaur website: Dinosaur Models and Toys.

Scientists have described a new unenlagiine theropod taxon from Argentina.  The new dinosaur has been named Diuqin lechiguanae.  Its fossils come from the Bajo de la Carpa Formation of the Neuquén Basin of Neuquén Province in northern Patagonia.  Diuqin lechiguanae has been described from fragmentary postcranial remains.  A broken tooth tentatively assigned to a megaraptor was found in close proximity to the specimen.  The left humerus (upper arm bone) has two, distinct puncture marks.  These marks have been interpreted as possible evidence of predation or post-mortem feeding traces on the Diuqin carcase.

Diuqin lechiguanae life reconstruction. Picture credit: Hannah Jones and Andrew McAfee.

Diuqin lechiguanae

This carnivorous theropod measured around 2.5 to 3 metres in length. The researchers identified a suite of unique anatomical characters. This enabled them to confidently erect a new taxon. Diuqin lechiguanae had hollow bones, and probably a long snout and jaws lined with short, but sharp teeth.

The genus name is derived from the language of the indigenous Mapuce people. It translates as “bird of prey”. The species name comes from “Lechiguana”, a witch in the 1975 horror film “Nazareno Cruz y el Lobo”. This film was directed by the eminent Argentinian filmmaker Leonardo Favio.  The binomial scientific name translates as “Lechiguana’s bird of prey”.

D. lechiguanae is the first unenlagiine to be described from fossils associated with the Bajo de la Carpa Formation. It lived around 85 million years ago (Santonian faunal stage of the Late Cretaceous). As such, it helps to plug a gap of several million years in the unenlagiine fossil record. This new dinosaur provides a fresh perspective on the evolution of theropods towards the origin of today’s birds.

The Unenlagiinae Subfamily

The Unenlagiinae are an enigmatic subfamily of theropod dinosaurs closely related to birds. Most palaeontologists consider them to be a subfamily of the Dromaeosauridae. However, their taxonomy remains controversial and more fossil discoveries may challenge this view. For example, a revision based on a more complete phylogenetic analysis could lead to their separation from the dromaeosaurids and the establishment of the family Unenlagiidae.

The oldest known unenlagiine described to date is Buitreraptor gonzalezorum.  Buitreraptor was named and described in 2005. Four fossil specimens of B. gonzalezorum were excavated from deposits associated with the Candeleros Formation (northern Patagonia). It is believed to have roamed Argentina approximately 98 million years ago (early Cenomanian faunal stage of the Late Cretaceous). The geologically youngest unenlagiine is the six-metre-long Austroraptor cabazai which, like Buitreraptor is known from fossils found in the Neuquén Province of Argentina.  Its fossils are associated with the Allen Formation.  Austroraptor lived around seventy million years ago.

A model of Buitreraptor gonzalezorum from the Beasts of the Mesozoic Wetlands Accessory Pack.

The model (above) is a representation of Buitreraptor gonzalezorum, the oldest unenlagiine theropod described to date.  The figure is from the Beasts of the Mesozoic articulated models range.

To view the range of Beasts of the Mesozoic figures in stock: Beasts of the Mesozoic Figures.

The Unenlagiinae subfamily was erected in 1999 by the distinguished Argentinian palaeontologist José Bonaparte (1999). It consists of several genera of small to medium-sized theropods and for the time-being they are confined to the southern portion of the Gondwana landmass (Antarctica and South America). Their geographical and temporal distribution may change as fossil specimens from Europe, North America, Madagascar and Australia have been putatively assigned to the Unenlagiinae.

Diuqin lechiguanae and Other South American Theropods

Other dromaeosaurids from Neuquén Province include Pamparaptor micros, Unenlagia paynemili and Neuquenraptor argentinus.  Both Unenlagia and Neuquenraptor are assigned to the Unenlagiinae, whilst the taxonomic placement of Pamparaptor as a member of the Unenlagiinae subfamily remains uncertain.

To read an article from 2021 about the discovery of an unenlagiine theropod from south-eastern Brazil (Ypupiara lopai): New Fish-eating Dinosaur from Brazil.

For an article describing a basal member of the Dromaeosauridae from Mongolia (Halszkaraptor escuilliei) that led to a revision of the Dromaeosauridae family: The Remarkable Halszkaraptor.

An article on the bizarre and possibly semi-aquatic Natovenator polydontus that illustrates the diversity of the Dromaeosauridae: New Research Suggests that Natovenator Hunted Fish.

Everything Dinosaur acknowledges the assistance of Dr Juan Porfiri (Universidad Nacional del Comahue, Buenos Aires) in the compilation of this article.

The scientific paper: “Diuqin lechiguanae gen. et sp. nov., a new unenlagiine (Theropoda: Paraves) from the Bajo de la Carpa Formation (Neuquén Group, Upper Cretaceous) of Neuquén Province, Patagonia, Argentina” by Juan D. Porfiri, Mattia A. Baiano, Domenica D. dos Santos, Federico A. Gianechini, Michael Pittman and Matthew C. Lamanna published in BMC Ecology and Evolution.

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