A newly described prehistoric reptile is giving scientists a surprising look at how some ancient animals may have changed the way they moved as they grew. Researchers say this "peculiar" crocodile relative likely began life walking on four legs, only to adopt a two-legged stance as it reached adulthood.

The species, called >Sonselasuchus cedrus>, belonged to a group of reptiles known as shuvosaurids. Many members of this group closely resembled ornithomimid dinosaurs, which lived alongside them during the Late Triassic period (approximately 225-201 million years ago).

>Fossil Evidence Points to Bipedal Movement>

In a peer-reviewed study published in the >Journal of Vertebrate Paleontology>, scientists from the University of Washington Department of Biology and the Burke Museum analyzed fossil remains and noticed unusual limb proportions. These findings suggest that the small, roughly poodle-sized reptile may have developed the ability to walk on two legs later in life.

"By analyzing the proportions of the limb skeletons of different animals, they determined its bipedal stance (standing on two feet) may have been the result of a differential growth pattern," explains lead author Elliott Armour Smith.

"We think that >Sonselasuchus> had more proportional forelimbs and hindlimbs as young, and their hindlimb grew longer and more robust through adulthood.

"Essentially, we think these creatures started out their lives on four legs… they then started walking on two legs as they grew up.