The 250 million year old fossil of crocodile ancestors

Scientists discovered a 250 million-year fossil of a crocodile-like ancient carnivorous lizard, surviving a massive extinction event that wiped out 90% of Earth's creatures.

Science Daily reported on March 11, a group of Brazilian and British scientists discovered fossils of the new reptile Teyujagua paradoxa dating back 250 million years in the state of Rio Grande do Sul in southern Brazil. The study was published in Scientific Reports, helping to clarify the process of this species evolving into dinosaurs, flying lizards, crocodiles and birds.

The name Teyujagua comes from the language of the Guarani people, meaning "ferocious lizards" , suggesting the legendary lizard dog Teyú Yaguá. Teyujagua has many intermediate characteristics between ancient reptiles and important animal groups "archosauriformes". Archosauriformes include all the extinct dinosaurs and flying lizards, along with birds and crocodiles today.

Artwork of ancient lizards that lived 250 million years ago.(Photo: Abigail Beall).

The discovery of Teyujagua reptiles is important because they lived right after the extinction in the Permian period - Triassic, 252 million years ago. This great extinction eradicated 90% of species living at that time. The reason is due to huge and intense volcanic eruptions in eastern Russia today.

The Teyujagua species provides new insights into the ecosystem of recovery and development after the extinction event. Terrestrial ecosystems then have fewer organisms, creating opportunities for some species to grow in number and diversity. Archosauriforms and some close relatives Teyujagua became dominant animals in the ecosystem, eventually evolving into dinosaurs.

Teyujagua is a 4-foot, 1.5 meter long carnivore. Their teeth are like saw blades and are quite strong. Two nostrils are located in the upper part of the snout, a feature commonly found in aquatic or amphibian animals like crocodiles today. Tujague can live on the shore of a lake or river. They hunt amphibians and procolophonids, extinct reptiles like small lizards.

"Teyujagua is a very important discovery, because it helps us understand the origin of the archosauriforms vertebrate group . Teyujagua fills the evolutionary gap between archosauriformes and primitive reptiles" , Richard Butler, Ph.D. at the University of Birmingham, England, said.