A fossilized femurMatheus Fernandes Gadelha & Rodrigo Temp Müller / UFSM
The dinosaurs that today inhabit only our imaginations did not yet exist 237 million years ago, but a small silesaurid was already running through what are now the plains of Rio Grande do Sul. The newly described fossil, named Gondwanax paraisensis, is one of the oldest in existence. It was used to identify specific characteristics of the animal. “The sacrum is further forward, composed of at least three vertebrae, and is very similar to that of the dinosaurs, which we did not expect in such an ancient animal,” explains paleontologist Rodrigo Temp Müller of the Federal University of Santa Maria (UFSM). The femur, less than 15 centimeters long, features a protrusion called the fourth trochanter, which serves as an anchor for the muscles that connect the leg to the tail and is also more developed in dinosaurs. These characteristics show that silesaurids were experimenting with different modes of locomotion. “One of the most interesting things about dinosaurs is that they ended up becoming bipedal running animals, and this is already visible in the origins of the group,” explains the researcher (Gondwana Research, September).
Artistic representation of G. paraisensisMatheus Fernandes Gadelha & Rodrigo Temp Müller / UFSM
