The 200-milllion-year-old fossils of a reptile recently discovered by scientists raised question of how four-legged animals evolved and thrived.
Although some fossils were almost crushed, making it hard to study, scientists were able to come up with 3D reconstructions of the reptile using the micro-CT (computerized tomography) scans.
The journal Current Biology published a study about the discovery.
Drepanosaurus lived in trees and survived by digging insects from the bark through its big hooked claws, similar to the anteaters of the South American jungles. The fossils suggested that the creature is as big as a cat, with a head resembling a bird and a body similar to a chameleon.
According to lead researcher Dr. Adam Pritchard of Yale University, Drepanosaurus has big arms. "The index finger is much much larger than any of the other fingers and supports this gigantic claw, which is easily the most massive bone of the entire arm," Pritchard said.
Researchers are amazed by the creature as it defies the rules consistent in tetrapods. The forelimbs of four-footed creatures always follow consistent rules throughout the million years of evolution. Drepanosaurus is expected to have parallel bones like the rest of the tetrapods.
"In your forearm, in the forearm of Tyrannosaurus rex, in the forearm of an elephant, you have two bones - the radius and the ulna, which manifest as these elongate, slender, parallel shafts," Pritchard explained.
Palaeontologist from the National Museums Scotland, Dr. Nicholas Fraser, said the Triassic period, the era when Drepanosaurus existed, was a "melting pot of experimentation." During this period, the unconventional dominates.
Researchers continue to excavate the quarries in New Mexico, hoping to unearth more interesting things.
