Hallopus was a prehistoric reptile, classified by O. C. Marsh in 1881 as a dinosaur. In fact it was probably a crocodilian or possibly a more primitive crurotarsan, and may be closely related to Junggarsuchus [1]. Image:Champsosaurus BW.jpg This reptile-related article is a stub. You can help Fossil Wiki by [ expanding it]. Image:Postosuchus BW.jpg This archosaur-related article is a stub. You can help Fossil Wiki by [ expanding it].