BUENOS AIRES, Oct. 10 (Xinhua) -- Researchers in Argentina have dug up a fossil of an unknown animal species that lived some 235 million years ago, officials from the National University of San Juan announced Thursday.
Oscar Alcober, a paleontologist and director of the university's Natural Sciences Museum, told a press conference that the remains are from an animal species about the size of an armadillo, which appears to be half reptile and half mammal.
The fossil was found in the western province of San Juan, where a highway is being built 200 km northwest of the regional capital San Juan city.
"The team worked two days and they found three skulls of an unknown species from the Triassic period," Alcober said.
He displayed the fossil remains, saying it was difficult to compare the species with others, but that the species could help understand the origin of mammals some 100 million years ago.
"It's a very important find," he said. "It has no name yet. There are three skulls, two incomplete and another complete, and vertebrae of proto-dinosaurs, which are key."