A new ornithomimid theropod from the Dinosaur Park Formation of Alberta, Canada

A partial ornithomimid skeleton, ROM 1790, from the lower Dinosaur Park Formation (upper Campanian) of Alberta was previously referred to <i>Struthiomimus altus</i>, but lacks diagnostic characters of that species. It is here described as the holotype of a new species, <i>Rativates evadens</i>, gen. et sp. nov., diagnosed by the form of the maxilla-jugal contact, the reduction of the mid-caudal neural spines, the convex fusion of the left and right ischial shafts, the straight-edged distal end of the third metatarsal, and possibly the relatively enlarged medial condyle of the tibia. A histological section of the femur confirms that the type specimen is not a juvenile, despite its relatively small size (approximately 50% the size of large individuals of <i>Struthiomimus altus</i>). Phylogenetic analysis recovers <i>Rativates</i> as a member of a derived ornithomimid clade that includes <i>Ornithomimus, Struthiomimus</i>, and the Asian taxa <i>Anserimimus</i> and <i>Qiupalong</i>. Fusion of the proximal tarsals to the tibia in some ornithomimid specimens was observed to be more complete than previously recognized, increasing the suite of features that these non-avian dinosaurs share homoplastically with birds. http://zoobank.org/urn:lsid:zoobank.org:pub:E0163526-7C26-4E8C-90C9-C72A3E90ED2D SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP Citation for this article: McFeeters, B., M. J. Ryan, C. Schröder-Adams, and T. M. Cullen. 2016. A new ornithomimid theropod from the Dinosaur Park Formation of Alberta, Canada. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1221415.