Anchisaurus is a genus of basal sauropodomorph. An early herbivorous dinosaur, it lived during the Early Jurassic Period; more specifically, the Pliensbachian to Toarcian ages, 190 to 174 million years ago. Until recently it was classed as a member of Prosauropoda. The name comes from the Greek αγχι/agkhi anchi-; "near, close" + Greek σαυρος/sauros; "lizard", probably referring to Marsh's interpretation of it as intermediate between primitive dinosaurs (at the time Palaeosaurus was an example of what was thought to be a primitive dinosaur) and more derived dinosaurs. Anchisaurus was coined as a replacement name for Amphisaurus, which was itself a replacement name for Hitchcock's Megadactylus, both of which had already been used for other animals.