Raptorex Discovered, Weighed As Much As Average Human

The researchers found that the skull of the Raptorex had enlarged olfactory bulbs by passing it through a CT scanner at the University of Chicago hospital. University of Chicago paleontologist Paul Sereno determined that this particular Raptorex lived to be five or six years old.

In a University of Chicago interview, Sereno explains that the skeleton of Raptorex was excavated by a local person and sold to a private owner. This private owner then approached Sereno, and the scientist made it clear that the skeleton was to be donated to science (and eventually returned to China). Had Raptorex stayed in private hands we would still be in the dark about this crucial point in tyrannosaur evolution.

In theory, T. rex dominated the landscape because of its large teeth, its crushing jaw and the powerful legs that could outrun most prey. T. rex grew in size because it was better than other predators. Dr. Sereno said Raptorex’s features were “a body blueprint for a predator. That blueprint proved to be scalable as the Tyrannosaurs grew in body size."

The researchers conclude that the "predatory skeletal design" of the Raptorex was simply scaled up with little modification in its carnivorous descendants, whose body masses eventually grew 90 times greater.

Sereno and his colleagues are using this new fossil to propose and describe three major morphological stages in the evolutionary history of tyrannosauroid dinosaurs.

image: www.marshalls-art.com
sources: University of Chicago, aaas.org