The type material of
Chaoyangsaurus consists mainly of dorsal cranial material including the mandible. There are are also some shoulder girdle materials and cervical vertebrae. The skull elements, particularly the maxilla and the mandible, contain the characteristics that associate the small dinosaur with its descendants, the ceratopsians. The teeth possessed similar wear patterns to those seen in definitive early ceratopsians and psittacosaurs like
Psittacosaurus. The snout of
Chaoyangsaurus and its jugals are also similar to those in ceratopsians. The jugal bones are a set of bones in the "cheek" of ceratopsian dinosaurs that give the larger dinosaurs their characteristically pointy jowls. Phylogenetic analyses taking these and many other characteristics into consideration in the original paper placed
Chaoyangsaurus into a polytomy with
Psittacosaurus and the base of the ceratopsian family tree proper.
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