In 1888, British paleontologist H.G. Seeley divided up the dinosaur family tree into two branches based on pelvic bones. However, a new analysis suggests a complete rearranging of this early tree. Matthew Baron of the University of Cambridge said, “Maybe we shouldn’t just blindly accept this 130-year-old idea… Seeley’s idea, while it was brilliant for his time, it’s arguably archaic.” Baron and his team analyzed 74 species of dinosaurs and found that 21 other anatomical features divide them differently. Based on these new features, the new tree places the tyrannosaurus rex and other theropods with the old “bird-hipped” species on one branch and the sauropods on another "non-bird-hipped branch." We never thought we would know so much about the dinosaurs hips.