A new species of titanosaurian dinosaur that ranged in weight from the size of a cow to that of a sperm whale has been discovered by researchers working in Argentina, according to a new study published Tuesday in the online edition of the open-access journal PLOS One.
The new species was identified based on a complete skull and partial neck fossil discovered by by Rubén Martínez from the Laboratorio de Paleovertebrados of the Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB) and his colleagues at a site in central Patagonia.
Identified as Sarmientosaurus musacchioi, the creature was a titanosaurian sauropod that lived during the Upper Cretaceous period, between 100.5 and 66 million years ago, the study authors wrote in their newly-published paper. Like all titanosaurs, it was a plant-eater with a long neck and tail, and its remains were found at the Bajo Barreal Formation in Chubut Province.
Discovery sheds new light on anatomical diversity of sauropods
The fossils were said to be well-preserved and anatomically primitive, and in a statement, the researchers said that they were analyzed using computerized tomography (CT) imaging scans. They discovered that Sarmientosaurus had a tiny brain relative to its rather large body, but also found evidence that it had greater sensory capabilities than most other sauropods.
Based on their CT scans and other analyses, Martínez and his co-authors concluded that this species had large eyeballs and could see quite well, and that the mechanics of its inner ear may have been designed for detecting sounds at lower frequencies than other types of titanosaurs.
Furthermore, the inner ear’s balance organ indicates that the Sarmientosaurus tended to keep its head facing downward, with the snout pointed towards the ground so that it could feed on plants growing close to the surface. The snout, along with the creature’s pneumatized cervical vertebrae and ossified cervical tendon, are rare features in this type of dinosaur and serve to broaden “our understanding of the anatomical diversity of this remarkable sauropod clade,” they wrote.
“Discoveries like Sarmientosaurus happen once in a lifetime. That’s why we studied the fossils so thoroughly, to learn as much about this amazing animal as we could,” Martínez added. The new species was named Sarmientosaurus musacchioi in honor of a town located close to where it was found, and late UNPSJB professor and paleontologist Dr. Eduardo Musacchio.
Image credit: WitmerLab, Ohio University.