London, Oct 6 (IANS) Dinosaurs might have been walking the earth nine million years earlier than previously thought.

A study of footprints found in Poland from the early Triassic age, indicate the first dinosaurs emerged a few million years after a species wipeout, called the Permian-Triassic extinction, but were a minor group in the panoply of life.

The footprints, thought to be about 250 million years old, are ‘the indisputably oldest fossils of the dinosaur lineage’, according to the researchers who carried out the study, reports the journal Proceedings of the Royal Society B.

These early dinosaurs were small, four-footed animals, but over the next 50 million years, their class diversified astonishingly, becoming leviathan herbivores and fleet-footed carnivores that dominated the planet, according to the Daily Mail.

Scientists from Poland, Germany and the US said the prints, along with those from two other slightly younger sites, provided important insight into the origin and early evolutionary history of dinosaurs.

Their footprints are small – roughly two to four centimetres (one to two inches) across – suggesting the creatures were about the size of a domestic cat.

They walked on four legs and were very rare compared to contemporary reptiles, the findings suggested.

The scientists, Stephen L Brusatte, Grzegorz Niedzwiedzki and Richard J Butler, wrote: ‘The Polish footprints prompt a substantial extension of early dinosaur history.