STAURIKOSAURUS
This Triassic dinosaur belonged to the Staurikosauridae family ("Southern Cross lizards" named after the star constellation seen in the Southern Hemisphere). Living in both North and South America during the middle to late Triassic, this six-and-a-half-foot dinosaur was probably as heavy as a human adult. It had large, sharp teeth, and it may have been the very first dinosaur to be able to attack bigger animals. No one has determined if this dinosaur was a theropod or a saurischian. It appears to be a primitive dinosaur.