Visit the David H. Koch Dinosaur Wing on the Museum's fourth floor, and you'll find a bevy of fossil dinosaurs, in two separate halls.
One is the Hall of Ornithischian Dinosaurs (Or-nuh-THISH-ee-an) dinosaurs, where you will find Stegosaurus, Triceratops, and more.
The other is the Hall of Saurischian Dinosaurs (Sawr-ISH-ee-an), where you can witness Tyrannosaurus rex, as well as Apatosaurus, and beyond.
What is the difference between these two groups of ancient reptiles? Find out more from Mark A. Norell, chair of the Division of Paleontology.