Researchers discovered a new species of carnivorous dinosaur that inhabited Patagonia 90 million years ago
CTyS-UNLaM Agency/DICYT The new species, named as Tralkasaurus cuyi, is much smaller than the carnivorous dinosaurs from the abelisaurus theropods group known until now. It measured about four meters and it was found at the northwest of Río Negro province.
The researcher Mauricio Cerroni of the Argentine Museum of Natural Sciences (MACN) and CONICET told the CTyS-UNLaM Agency that “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.”
“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 was found”, said the lead author of the study published in Journal of South American Earth Sciences.
Dr. Federico Agnolín, also a researcher at MACN, CONICET and Félix de Azara Natural History Foundation, observed that “the body size of the Tralkasaurus is smaller than other carnivores in this group, the abelisaurs are around four meters long, while the previously known are between seven and eleven meters”.
In theropods dinosaurs group is, for example, the famous Tyrannosaurus rex, which is native to North America, which reached 14 meters, or the Carnotaurus sastrei from Chubut (which also won some fame in Hollywood with a Disney movie) that reached 10 meters long. "The Tralkasaurus, because of being much smaller, reveals that the group of abelisaurus 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 which has horns), this new Río Negro’s 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.
According to the authors of this study, it is possible that Tralkasaurus fed on the small herbivorous dinosaurs known as iguanodontes, which were found by the same team of palaeontologists in nearby locations, along with other species such as turtles and lizards.
"One of the importance of this new discovery is that it helps us to define the ecological habits of both carnivorous dinosaurs and herbivores," said Cerroni.
The peculiarities of the "thunder reptile"
Dr. Federico Agnolín told the CTyS-UNLaM Agency 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, in instead of having horns like Carnotaurus, it could have had small or poorly developed 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 supports the rib that is very thin, something that has never been seen in any other group of carnivores".
The name, which this new abelisaurid 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 Rio Negro.
The study of this new species found in the Ezequiel Ramos Mejía Reservoir, 25 kilometres from the city of Villa El Chocón, also included researchers Matías Motta, Alexis Aranciaga Rolando, Federico Brissón Egli and Fernando Novas from MACN and CONICET.