Messy History

O.C. Marsh

Nineteenth century dinosaurs from North America are often confusing and jumbled. There are quite a few good reasons for that and the major reason that pretty much always sums up what caused such confusion hovers around the names Marsh, Cope, and Leidy (Leidy is not often between the others but was close to Cope). This week's dinosaur, however, was only confusing because it was massively confused, not because of infighting between paleontologists. Edward Hitchcock initially described this East Coast sauropodomorph and named it Megadactylus polyzelus in 1865. Twenty years later O.C. Marsh recognized the name as previously occupied and renamed the animal Anchisaurus polyzelus. Fossils recovered separately named Amphisaurus polyzelus Marsh 1882 and Yaleosaurus colurus Huene 1932 were later synonymized with Anchisaurus. The type specimen remains Anchisaurus polyzelus Hitchcock 1865. Anchisaurus is unique for a number of reasons including being an East Coast dinosaur, a sauropodomorph, and being mistaken for human remains at one point. Anchisaurus is a small bipedal dinosaur with an herbivorous diet known from Connecticut and Massachusetts with potential sister taxa discovered in Chinese and South African formations of the Early Jurassic (200 - 188 million years ago).