A large jaw of a kind of predatory archosaurs of the last Triassic in the south of the Wales, named Zanclodon Cambrensishas long been intrigued paleontologists. Could it be the oldest theropode dinosaur? In a new study, paleontologists from the University of Bristol and the National Cardiff museum have reanalyzed the specimen on the basis of a new 3D digital reconstruction. They first confirmed that it was indeed the age of the last Triassic, most likely extracted from the sandstone of the member of Cotham from the formation of Lilstock; Anatomically, the sample shows the characteristics of theropod dinosaurs and probably represents a kind of dinosaur at the beginning of the neotheropod, named Newtonsaurus Cambrensis.
The two separate blocks containing the printing of the jaw of Newtonsaurus Cambrensis. Image credit: Evans and al., DOI: 10.1016 / J.PGEOLA.2025.101142.
“This specimen has been referred several times in scientific articles, but had not yet been successfully identified – we did not even know if it were dinosaur,” said Dr. Owain Evans, paleontologist at the University of Bristol.
“He was appointed Zanclodon Cambrensis by Edwin Tully Newton in 1899, but we knew the name Zanclodon had been abandoned as referring to a wide variety of first reptiles. »»
“Consequently, we call it after Newton, calling him Newtonsaurus. It is different from all the other dinosaurs of that time and requires a distinctive name. »»
Newtonsaurus Cambrensis Toamed our planet about 202 million years ago (last period of the Triassic).
The fossil was found in the locality of Stormy Down near Bridgend, Wales, the United Kingdom.
The specimen is the natural mold of a left jaw, showing both the interior (housed at the National Museum of Wales) and external surfaces (hosted at the British Geological Survey)
“The natural mussels of the interior and exterior faces of the jaw show incredible details – each groove, crest, tooth and even the serrated along the edges of the teeth,” said Professor of the University of Bristol, Michael Benton.
“We decided to use digital photography to create a 3D model.”
“We started with the surface scanning of the fossil using photogrammetry.”
“Once we had our digital scan, we then reversed it – essentially giving us a digital negative of the mold.”
“It was then a simple case of fusion on both sides together and to analyze the anatomy from there.”
“The digital reconstruction that we have extracted from the sample gives a much better idea of what the original structure of the bone looks like.”
Now that the fossil could be studied, the team was able to use its anatomy to reconstruct its position in the family tree of reptiles – and above all – whether it is a dinosaur or not.
“We can now confirm that this specimen most likely belonged to a large predator dinosaur of Théropode, who traversed the banks of the southern Wales during the last Tria,,” said Dr. Evans.
“It has unique dinosaur characteristics defined in the installation of teeth, and it is a theropode – a predatory dinosaur and eater of flesh.”
“Otherwise, it is close to the origins of the two main divisions of Theropoda, Celophysoidea and Averostra.”
“The most unexpected is the size of the animal. The preserved jaw measures 28 cm long, and it’s just half front, so originally the jaw was 60 cm, corresponding to a dinosaur with a body length of 5 to 7 m.”
“It is unusually large for a trias theropod, most of which were half the size or smaller.”
“These historical specimens are of vital importance in paleontology and often give new and exciting results – even if they have been sitting in collections for years,” said Dr. Cindy Howells, paleontologist at the National Cardiff Museum.
“Victorians were fascinated by the fossil and prospered file throughout the United Kingdom for fossils.”
“In addition to that, the redistscue of Newtonsaurus Cambrensis Once again, underlines the meaning of Wales in paleontological research. »»
“These Triassic beds are rare in the world, and yet there are many through Wales.”
“There could very well be another dinosaur waiting to be discovered.”
The results have been published online today in the Proceedings of the Association of Geologists.
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Owain Evans and al. Revaluation of a large dental archosaur of the trias of the southern Wales, United Kingdom. Proceedings of the Association of Geologistspublished online on September 11, 2025; DOI: 10.1016 / J.PGEOLA.2025.101142
