1) Battles between Tyrannosaurus rex and stegosaurus were common.
2) The Tyrannosaurus rex had a brain that was larger than that of most other dinosaurs.
3) All dinosaurs lived on land; none lived in the seas.

Answer — 1) False. Tyrannosaurus rex did not appear until after the Stegosaurus had been extinct for about sixty million years. 2) True. 3) True. Ichthyosaurs were huge sea creatures (7-30 feet long), but they were lizards, not dinosaurs.