A 250-million-year-old fossil of an ancient crocodile-like reptile, Teyujagua paradoxa, was found in southern Brazil last year. Paleontologists expect that the fossil will provide information to researchers about the evolution of dinosaurs on Earth and what could have caused their extinction.

The fossil discovery was made by researchers from the Paleobiology Laboratory of the Universidade Federal do Pampa at Triassic rock in Rio Grande do Sul, Brazil.

A related study has been published in Scientific Reports this week. The study informed that Teyujagua paradoxa grew up to five feet long and it would have stalked prey in the shallow regions of rivers and lakes. The word Teyujagua has come from Teyú Yaguá, meaning a “fierce lizard” seen as a reptile with the head of a dog. The word has been derived from the indigenous language of the local Guarani people and Teyujagua was one among seven mythical beasts in the folklore of the ethnic group.

The new species shows morphological characteristics, including serrated teeth, which would eventually give rise to Tyrannosaurus Rex.

The newly discovered fossilized skull has caught the fancy of paleontologists working in the field. The skull is of transitional form and reportedly survived ‘The Great Dying’ about 250 million years ago. It is expected to bridge the gap in our understanding of how dinosaurs evolved from their earlier reptile cousins.

Felipe Pinheiro, from Universidade Federal do Pampa, São Gabriel, Rio Grande do Sul, said while Teyujagua doesn't have a head that could be reasonably compared to that of a dog, it is believed to have roamed much of the same territory as the mythical beast.

“But the discovery of Teyujagua's skull was still really exciting. Ever since we saw that beautiful skull for the first time in the field, still mostly covered by rock, we knew we had something extraordinary in our hands”, said Pinheiro.