Fossil remains of a skull, which include the maxillary bone and some teeth, have revealed a new species of carnivorous dinosaur who lived in Patagonia 90 million years ago.
The new species, called Tralkasaurus cuyi, is much smaller than carnivorous dinosaurs from the group of abelisaurus theropods known so far. It measured about four meters and was in the northwest of the province of Río Negro.
The researcher Mauricio Cerroni of the Argentine Museum of Natural Sciences (MACN) and CONICET told the Agency CTyS-UNLaM that “the materials found are diagnostic to describe this new species”.
“As for the rest of the skeleton, cervical ribs were found, that leave the neck and are very long, so it is believed that they are tendons that have fossilized; in addition, part of the spine of the hip and tail was found, “said the lead author of the study published in the Journal of South American Earth Sciences.
Smaller than other carnivores
Dr. Federico Agnolín, also a researcher at the MACN and CONICET Natural History Foundation, observed that “the body size of the Tralkasaurus is smaller than that of other carnivores in this group, the abelisaurs are about four meters long, while the previously known are between seven and eleven meters. “
In the group of theropod dinosaurs is, for example, the famous Tyrannosaurus rex, which is native to North America, which reached 14 meters, or the Carnotaurus sastrei of Chubut (which also gained fame in Hollywood with a movie from Disney) which reached 10 meters long. “The Tralkasaurus, being much smaller, reveals that the abelisaurus group of theropods encompassed a much wider ecological niche than previously thought,” said Cerroni.
Although its size is very small compared to the Tyrannosaurus or Carnotaurus (a species that has horns), this new Río Negro dinosaur shares with them the characteristics of being a biped animal, short-necked and muscular, with four claws on each of its hind legs, while its arms were also very short in relation to its body and the bones of its extremities were light and hollow.
He fed on iguanodontes
According to the authors of this study, it is possible that Tralkasaurus has fed on the small herbivorous dinosaurs known as iguanodontes, which were found by the same team of paleontologists in nearby places, along with other species such as turtles and lizards.
“One of the importance of this new discovery is that it helps us define the ecological habits of carnivorous dinosaurs and herbivores, “said Cerroni.
Federico Agnolín said that “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, instead of having horns like Carnotaurus, could have had small or underdeveloped corneal structures. “
Meanwhile, Cerroni highlighted a particularity in the bones of the middle region of the column of this new species. “There is an element that holds the rib that it’s very skinny, something that has never been seen in any other group of carnivores. “
The name with which this new abelisaurido dinosaur was baptized, comes from the Mapundungum, colloquially known as the Mapuche language, and means “Thunder Reptile”. The middle name “cuyi” refers to the place where it was found, the El Cuy plateau, in the province of Río Negro.