Othniel Charles Marsh
In 1878, the most complete sauropod yet was found and described by Othniel Charles Marsh, who named it "Diplodocus". With this find, Marsh also created a new group to contain "Diplodocus", "Cetiosaurus", and their increasing roster of relatives to differentiate them from the other major groups of dinosaurs. Marsh named this group Sauropoda, or "lizard feet".