Once A Hypsilophodont

©Robinson Kunz

Originally diagnosed as a middle of the group Hypsilophodontid, Atlascopcosaurus, has since been reassigned to the honored position of one of the basal-most Ornithopoda. Hypsilophodontidae would still be recognized as the family to which Atlascopcosaurus is assigned had it not been deemed paraphyletic and effectively banished from dinosaurian systematics. Regardless, as a basal member of the Ornithopoda Atlascopcosaurus possesses many characters that define the clade later on. Bipedal herbivores, Ornithipoda like Atlascopcosaurus, possess predentary beaks and occluding grinding teeth in a distinctive cheek region along the maxilla and dentary. They also should, remember that Atlascopcosaurus remains are exceedingly fragmentary postcranially, possess ossified tendons along the caudal vertebrae that stiffen the tail, making structurally very much like a cantilever bridge; it provides stability and support to balance out the center of gravity oriented in the upper thoracic area. The nearly horizontal body position is well exhibited in this illustration, and the feathering or filamentous fibers, are a fairly certain reality as well at this point. Small basal members of Ornithopoda are no longer so bland as they used to be thankfully.