Tralkasaurus cuyi: New Carnivorous Dinosaur Unearthed in Argentina

Tuesday, February 18, 2020

An artist’s impression of Tralkasaurus cuyi. Image credit: Sebastian Rozadilla.

A new genus and species of medium-sized abelisaurid dinosaur being named Tralkasaurus cuyi has been discovered by Dr. Mauricio Cerroni from the Argentine Museum of Natural Sciences and CONICET and his colleagues.

Tralkasaurus cuyi lived approximately 90 million years ago in what is now Patagonia, Argentina.

It belongs to Abelisauridae, a group of ceratosaurian theropod dinosaurs that thrived during the Cretaceous period on the supercontinent Gondwana.

The incomplete fossilized skeleton of Tralkasaurus cuyi, including a jaw and vertebra, were discovered at the Violante Farm fossil site in Río Negro province, northern Patagonia.

“The materials found are diagnostic to describe this new species: the maxillary bone, that is part of the snout, was found from the skull and it still preserves some teeth,” said Dr. Cerroni, the lead author of a paper published in the Journal of South American Earth Sciences.

“As for the rest of the skeleton, cervical ribs were found, which come out from the neck and are very long, so it is thought that they are tendons that have fossilized; in addition, part of the hip and tail spine were found.”

Tralkasaurus cuyi was about 4 m (13 feet) long, smaller than previously known species of abelisaurid dinosaurs.

“The size of Tralkasaurus cuyi contrasts with that of typical abelisaurids such as Abelisaurus and Carnotaurus (between 7 and 11 m, or 23-36 feet long), indicating that it would occupy a different ecological niche,” the paleontologists said.

“Although its size is very small compared to Tyrannosaurus or Carnotaurus, the newly-discovered dinosaur shares with them the characteristics of being a biped animal, short-necked and muscular, with four claws in each of its hind legs, while its arms were also very short in relation to its body and the bones of its limbs were light and hollow,” Dr. Cerroni said.

“The snout of this new species has a lot of ornamentation, that is, an outer surface marked by roughness (a characteristic of the snout of these carnivores), which makes us assume that, in instead of having horns like Carnotaurus, it could have had small or poorly developed corneal structures,” said team member Dr. Federico Agnolin, a researcher at the Argentine Museum of Natural Sciences, CONICET, and the Universidad Maimonides.

Tralkasaurus cuyi likely preyed upon small animals which would likely include small herbivorous dinosaurs known as iguanadontians, turtles and lizards.


M.A. Cerroni et al. 2020. A new abelisaurid from the Huincul Formation (Cenomanian-Turonian; Upper Cretaceous) of Río Negro province, Argentina. Journal of South American Earth Sciences 98: 102445; doi: 10.1016/j.jsames.2019.102445