Tyrannosaurus Rex's likely ancestors started small, but perfectly armed, some 125 million years ago, dinosaur researchers reported Thursday.
Puny arms, massive jaws, swift legs all the ingredients of the king of the carnivores adorned a newly discovered dinosaur, Raptorex kriegsteini, reported by the journal Science. But Raptorex was only about 1/90 the size of Tyrannosaurus, and flourished about 40 million years before T.Rex appears in the fossil record.
