Tiny T. rex-like tyrants
Fossil find suggests peculiar features weren’t limited to the biggest dinosaurs
A miniature version of Tyrannosaurus rex is throwing a bone to paleontologists interested in how the king of dinosaurs evolved.
The newly discovered species, called Raptorex kriegsteini, lived tens of millions of years before T. rex and shares many similar features, suggesting it could be a direct ancestor of T. rex, researchers report online September 17 in Science. Raptorex possessed a Tyrannosaurus body plan — with a large head, strong legs and jaws, and puny forelimbs — which reveals that traits once thought particular to large predators could have been useful to smaller animals who had them as well.
“It was the common perception that the arms got smaller as the animals grew bigger,” says study author Paul Sereno of the University of Chicago. “No one had any idea there was something like Raptorex lurking around.”