2 square metres in size. The animals were probably buried under lake sediment soon after they died, with the flow of water repositioning their bodies on the lake bed and putting them in close proximity to one another. In 1877, German paleontologist Oscar Fraas assigned these specimens to the newly erected genus Aetosaurus. Fraas named the genus after the skull's resemblance to the head of an eagle, with a narrow, elongate skull and a pointed snout. First American aetosaurs The first aetosaurs from North America were also being described in the 1870s. American paleontologist Edward Drinker Cope named Typothorax in 1875 and Episcoposaurus in 1877, both of which were from New Mexico. However, Cope considered these genera to be phytosaurs, crocodile-like aquatic archosaurs that were also common in the Late Triassic. While new material referable to Typothorax has been found in recent years throughout the American southwest, Episcoposaurus is no longer considered valid. Cope, along with later paleontologists such as Friedrich von Huene, recognized that remains of the type species E. horridus actually belonged to Typothorax. At the time, Cope considered Aetosauria to belong to Rhynchocephalia, an order of reptiles that includes the living tuatara. He also thought that the tightly fitting osteoderms, which were thought to be fused to the ribs, indicated that aetosaurs were transitional between rhynchocephalians and turtles. Another species, E. haplocerus, was reassigned to Desmatosuchus in 1953. A third North American genus called Stegomus was named by Othniel Charles Marsh in 1896. Marsh had a long-time rivalry with Cope that was made famous in the Bone Wars of the late 19th century, in which the two tried to out-compete one another in the field and in scientific literature. Unlike Cope's aetosaurs, Stegomus was found from the eastern United States in Connecticut. Marsh also recognized Stegomus as an aetosaur rather than a phytosaur in his initial description of the genus. Like Cope, many paleontologists tended to consider aetosaur scutes to belong to phytosaurs during this time period. Marsh considered aetosaurs to be closely related to dinosaurs based on their elongated metatarsals (foot bones). As a distinct group, Aetosauria was named in 1889 by English naturalist Richard Lydekker and zoologist Henry Alleyne Nicholson. They considered Aetosauria to be one of three suborders of the order Crocodilia, the other two being Parasuchia (a group including phytosaurs and other Triassic forms) and Eusuchia (a group including all post-Triassic crocodylomorphs). Nicholson