A scale model of the Triceratops horridus dinosaur that existed in the Late Cretaceous Period (68-65 mya).  It is on display at the Smit...

Picture of three casts of dinosaurs.  The fossil casting on the left is a Protoceratops andrewsi of the Late Cretaceous Period (85-80 mya...

A Pachychormus bollensis fish fossil from the early Jurassic Period (195 million years ago) of Germany.  Displayed at the Smithsonian Mu...