Elaphrosaurus (Greek for "lightweight lizard"); pronounced eh-LAFF-roe-SORE-us
Woodlands of Africa
Late Jurassic (150 million years ago)
Size and Weight:
About 20 feet long and 500 pounds
Slender build; fast running speed
Elaphrosaurus ("lightweight lizard") comes by its name honestly: this early theropod was relatively svelte for its length, only 500 pounds or so for a body that measured 20 feet from head to tail. Based on its slender build, paleontologists believe Elaphrosaurus was an exceptionally fast runner, though more fossil evidence would help nail down the case (to date, the "diagnosis" of this dinosaur has been based on only one incomplete skeleton). The preponderance of the evidence points to Elaphrosaurus being a close relative of Ceratosaurus, though a shaky case can also be made for Coelophysis.