Different species are found up and down the coast of the Western Interior Seaway 1, 3– 6, and multiple species frequently occur in a single habitat. Chasmosaurines were especially diverse in the late Campanian. The Chasmosaurinae is a diverse group of horned dinosaurs that flourished during the Late Cretaceous of western North America 1, 2. However, the resulting phylogenies may lead to paraphyletic species and genera. The systematics of Chasmosaurus show how specimen level phylogeny can provide an evolutionary framework upon which to establish taxonomies. nov, including specimens previously referred to C. Accordingly, Chasmosaurus can be divided into three species: C. irvinensis, and the Peabody skull is closer to C. Specimen-level phylogenetic analysis provides a hypothesis of relationships upon which to base the taxonomy of Chasmosaurus. irvinensis, including a posteriorly inclined narial strut, brow horns replaced by rugose bosses, reduced parietal emargination, five pairs of epiparietals, and epiparietals that fuse at their bases and hook forward over the frill. Yet the skull also exhibits derived features of C. belli-like features include large, triangular lateral epiparietals, large parietal fenestrae, and an emarginate parietal. The Yale skull is intermediate between typical C. Here, the Yale Chasmosaurus skull is described, and implications for Chasmosaurus systematics are explored. irvinensis, recently placed in a new genus, Vagaceratops.

russelli, are currently recognized, with a third species, C. The horned dinosaur Chasmosaurus from the late Campanian Dinosaur Park Formation of Alberta, is known from numerous skulls and skeletons, but over a century after its description, the taxonomy of the genus is controversial.

Chasmosaurus jurassic world evolution