A newly identified genus and species of carnivorous herrerasaurid dinosaur has been revealed from a well-preserved skull unearthed in northern New Mexico.
This newly discovered dinosaur species lived approximately 201 million years ago during the Rhaetian period of the Late Triassic era.
Identified as Ptychoterates buculentus, this species offers a rare glimpse into a lesser-known chapter of dinosaur evolution.
“Dinosaurs emerged during the Carnian period (237 to 227 million years ago) in the early Late Triassic and eventually branched into three lineages that thrived into the Jurassic: ornithischians, theropods, and sauropods,” explained Virginia Tech paleontologists Simba Srivastava and Stirling Nesbitt.
“While most of the earliest dinosaur fossils have been found in high-latitude regions of Pangea (present-day Brazil, Argentina, Zimbabwe, and India), comparable dinosaur remains from lower latitudes (like Late Triassic deposits in the southwestern United States and Morocco) are rare.”
The fossil remains of Ptychoterates buculentus include a nearly complete skull, which features an intact braincase and the majority of the skull roof, discovered in 1982 at the Coelophysis Quarry in northern New Mexico.
The skull measures about 22 cm (9 inches) in length, indicating it was a relatively tall and narrow-headed dinosaur.
“The skull reveals this species had prominent cheekbones, a broad braincase, and likely a short, deep snout,” added the paleontologist.
“These characteristics are the first of their kind seen in early dinosaurs, highlighting the ongoing evolution of these magnificent creatures.”
Ptychoterates buculentus belongs to one of the earliest-known families of carnivorous dinosaurs, the Herrerasauria.
This species is closely related to two other Triassic dinosaurs, Tawa Harae and Chindesaurus briansmalli.
These species form part of a newly defined clade, Morphoraptora, characterized by a mix of anatomical traits found in both primitive dinosaurs and later theropods.
“Our anatomical comparisons with other Triassic archosaurs support the identification of Ptychoterates buculentus as a new taxon within the saurischian dinosaurs, closely linked to Tawa Harae,” explained the researchers.
“More broadly, our findings position Ptychoterates buculentus as a member of Morphoraptora, a clade known primarily from Late Triassic deposits in the southwestern United States.”
Previously, scientists believed that by the late Triassic period, the earliest lineages of carnivorous dinosaurs had vanished, replaced by more advanced theropods.
However, the discovery of Ptychoterates buculentus indicates that some of these lineages survived much longer than anticipated, at least in the lower latitudes of the ancient supercontinent Pangea.
“Ptychoterates buculentus was found in strata that appear to date just before the Great Extinction at the end of the Triassic, and members of this family never appeared again, suggesting that this group perished due to the mass extinction,” the scientists noted.
“This finding necessitates a reevaluation of the end-Triassic extinction’s impact, showing that it not only eliminated competing dinosaur species but also long-established dinosaur lineages,” Srivastava added.
“Furthermore, since herrerasaurids have not been discovered elsewhere in the Late Triassic, it is likely that what is now the American Southwest served as the final refuge for these dinosaurs.”
The discovery of Ptychoterates buculentus is detailed in a research paper published in this week’s edition of the journal Paleontology Papers.
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Simba Srivastava & Sterling J. Nesbitt. 2026. A new taxon of saurischian dinosaurs (Triassic: modern Norian or Rhaetian) from Coelophysis Quarry in New Mexico, USA, highlighting the diversity of Herrerasaurus in the Late Triassic. Paleontology Papers 12 (2): e70069; doi: 10.1002/spp2.70069
Source: www.sci.news
