Traces of footprints barely two centimeters long belonging to primitive dinosaurs with a size similar to that of a domestic cat have been found in Poland . The footprints were left during the early Triassic 250 million years ago , paleontologist Stephen Brusatte and his team at the New York Museum of Natural History reveal in the journal Proceedings of the Royal Society B.
The finding advances the date of appearance of the first dinosaurs by 9 million years , and implies that they emerged only 1 or 2 million years after volcanic eruptions, sudden global warming and the stagnation of the oceans that destroyed 90% of life on Earth (the mass extinction of the Permian-Triassic periods).
Analysis of the tracks suggests that these early dinosaur-like animals weighed less than two kilos and walked on all fours . "Footprints from Poland tell us that the first dinosauromorphs were quadrupeds, and that bipedalism took some time to appear," Brussate clarifies.
