Earliest known T. rex relative may have been found[ Thu, 13 Jan 2011 19:33:12 GMT ]What may be the earliest known relative of T. rex and all meat-eating dinosaurs has been discovered. The dog-sized mini-predator would've made its future relatives proud as it fed on small dinosaurs and the young of other reptiles, and is now shaking up what scientists had previously learned about the evolution of those extinct giants.