plat·e·o·saur·us 
(plătē-ō-sôrəs)
(plătē-ō-sôrəs)n.
A large herbivorous prosauropod dinosaur of the genus Plateosaurus of the Triassic Period, having a long neck and tail and a small head with leaf-shaped teeth.
[New Latin, genus name : Greek platus, plate-, wide, broad, flat (from the broad, robust nature of the bones of the type specimen ); see plat- in the Appendix of Indo-European roots + Greek sauros, lizard.]