The sizable jaws of the predatory alxaurus species from the latest Triassic period in South Wales, Zanclodon cambrensis, have long captivated researchers. Could it be the oldest large theropod dinosaur? In a recent study, paleontologists from the University of Bristol and Cardiff’s National Museum examined the specimens using advanced 3D digital reconstruction techniques. They first confirmed that the specimens dated to the late Triassic period, likely sourced from the sandstones of the Kotam members of the Lilstock Formation. Anatomically, these specimens exhibit characteristics typical of theropod dinosaurs, potentially representing early, novel therapy-footed species such as Newtonsaurus cambrensis.
Two separate blocks containing the impression of the jaw Newtonsaurus cambrensis. Image credit: Evans et al., doi: 10.1016/j.pgeola.2025.101142.
“This specimen has been mentioned in various scientific papers, yet its identity remains elusive. We were uncertain if it was even a dinosaur,” states Dr. Owain Evans, a paleontologist at the University of Bristol.
“Originally named Zanclodon cambrensis by Edwin Tully Newton in 1899, we learned that the name Zanclodon had been abandoned as it referred to a broad range of early reptiles.”
“Therefore, we honor Newton by naming it Newtonsaurus. It stands apart from all other dinosaurs of that time and warrants a unique designation.”
Newtonsaurus cambrensis roamed the Earth approximately 202 million years ago during the late Triassic.
The fossil was uncovered in a tempestuous area near Bridgend, Wales, UK.
The specimen represents the natural form of the left jaw, revealing both its interior (housed at the National Museum of Wales) and the outer surface (held at the British Geological Survey).
“The natural form of the inner and outer jawbone displays astonishing serrated details along the grooves, ridges, teeth, and even the edges of the teeth,” commented Professor Michael Benton from the University of Bristol.
“We opted to create a 3D model utilizing digital photography.”
“Our process began with surface scans of the fossils through photogrammetry.”
“Once I obtained a digital scan, I reversed it which provided a digital negativity.”
“It was simply a matter of merging both sides and analyzing the anatomy from there.”
“Digital reconstructions derived from specimens give us a considerably clearer understanding of the original structure of the bone.”
Now that the fossils have been examined, the team could utilize their anatomy to ascertain their positions in the reptile family tree, determining importantly whether they are dinosaurs.
“We can assert that this specimen is highly likely a member of the large predatory theropod dinosaurs that inhabited the South Wales coast during the late Triassic,” Dr. Evans remarked.
“The arrangement of the teeth exhibits a distinct, extraordinary dinosaur feature, identifying it as a carnivorous predator.”
“If it’s not a true dinosaur, it closely ties to the origins of the two major divisions of Coelophysis, namely Coelophysodia and Averostra.”
“The most surprising aspect is the size of the creature. The preserved jawbone measures 28 cm in length and constitutes just the front half; originally, it likely corresponded to dinosaurs measuring 60 cm in length, with a total body length of 5-7 m.”
“This size is exceptionally large for Triassic theropods, which predominantly were under half that size.”
“Such historical specimens are invaluable in paleontology, frequently yielding new and enlightening insights, even after years of dormancy in collections,” stated Dr. Cindy Howells, a paleontologist at the National Museum in Cardiff.
“Wales holds a treasure trove of fossil records, with a dense concentration of fossils across the UK.”
“Furthermore, Newtonsaurus cambrensis reiterates the significance of Wales in paleontological exploration.”
“These Triassic strata are scarce worldwide, but several can be found in Wales.”
“It’s quite plausible that another dinosaur may be discovered here.”
Survey results were published online today in Proceedings of the Geologists Association.
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Owain Evans et al. A reevaluation of a large orxaurial dentistry from the Late Triassic in South Wales, England. Proceedings of the Geologists Association published online on September 11th, 2025. doi: 10.1016/j.pgeola.2025.101142
Source: www.sci.news
