Nodosaurus (meaning "knobbed lizard") was a large, armored, quadrupedal (it walked on four legs), tank-like dinosaur. It lived in the first part of the Upper Cretaceous about 113–98 million years ago. Three very incomplete "Nodosaurus" fossils have been found in Wyoming and Kansas; no skulls have been found yet. It was named by paleontologist Othniel C. Marsh in 1889.