A footprint left by a cat-sized dinosaur around a hundred million years ago has been discovered in China by a team of paleontologists. Details of the study are published in the journal Palaios.
Stegosaurids are an extinct family of quadrupedal herbivorous ornithischian dinosaurs that lived approximately 163.5 to 100.5 million years ago. All members of this family can be recognized by a massive, stocky body, tiny head and bony plates, as well as spines rising up on their backs and tails.
An international team of paleontologists led by Dr Anthony Romilio, from the University of Queensland (Australia), announces that they have identified one of these dinosaurs in Xinjiang province, China, thanks to one of its traces printed in floor.
Originally discovered by Associate Professor Lida Xing, Chinese University of Geosciences (Beijing), this imprint only measures 5.7 cm long. It is the smallest footprint of stegosaurids ever discovered.
“This contrasts sharply with other stegosaurid footprints found at the Chinese trail site which measured up to one foot.“, Emphasizes Dr Anthony Romilio. “Some, found in Western Australia, can also measure up to eighty centimeters“. According to the authors, it would have been printed by an animal the size of a cat, probably a young individual.
Some kind of “bipedal walk”?
The small footprint has similar characteristics to other Stegosaurid footprints identified by their three short, wide, round fingers. However, the researchers noted a difference with similar larger prints, suggesting that the young Stegosaurus didn’t move the same way.
“Stegosaurs typically walked with heels on the ground, just like humans, but on all fours, creating long footprints“, Continues the researcher. “In contrast, the tiny trail shows that this dinosaur moved with its heel lifted off the ground, much like a bird or a cat does today. This type of shortened trail usually involves bipedal dinosaurs“.
According to Associate Professor Xing, these animals could thus have switch to heel walking as you get older. “A full set of traces of these tiny footprints would provide us with the answer to this question, but unfortunately we only have one footprint.“, She laments, recalling in passing that“footprints made by tiny armored dinosaurs are much rarer than those formed by other groups of dinosaurs“.