One of the earlier dinosaurs to appear on Earth was Coelophysis. It was a small, but skilled hunter that lived during the Late Triassic Period over 200 million years ago. Coelophysis was also one of the first therapods, a group of two-legged, mostly carnivorous dinosaurs that would later include hunters like the Tyrannosaurus rex. Of course, Coelophysis was much smaller than T. rex-but also probably much faster.

Image credits: main image, Sean Murtha; Sterling Nesbitt: courtesy of AMNH.