Dromiceiomimus

Dromiceiomimus is a genus of ornithomimid theropod from the Late Cretaceous (early Maastrichtian) of Alberta, Canada.

Taxonomy
The type species, D. brevitertius was originally described as a species of Struthiomimus by William Parks in 1926 on the basis of a partial postcranium, ROM 797, from the Horseshoe Canyon Formation of Alberta, Canada.[1]

In his review of Canadian ornithomimids, Dale Russell made S. brevitertius the type species of a new genus, Dromiceiomimus, meaning "Emu mimic" from the old generic name for the emu, Dromiceius. Russell also synonymized Struthiomimus ingens with Dromiceimimus brevitertius. He renamed Ornithomimus samueli into a second Dromiceiomimus species: Dromiceiomimus samueli Dromiceiomimus was distinguished from Ornithomimus edmontonicus on the basis of the following characters: humerus shorter than scapula; ulna ~70% of femoral length; preacetabular process, tibia, metatarsus and pedal digit III longer compared to femur.[2]

In a 1981 publication, however, Nicholls an Russell cast doubt on the validity of Dromiceiomimus and treated it as synonymous with Ornithomimus, arguing that the limb proportions might be insufficient to distinguish it from Ornithomimus.[3] In the second edition of the Dinosauria, Makovicky et al. claimed that there is no statistical support for the distinction of Dromiceiomimus from Ornithomimus and synonymized it with Ornithomimus edmontonicus.[4]

However, a few authors continued to treat Dromiceiomimus as valid, and Longrich (2008, 2014) treated ROM 840 (holotype of Struthiomimus samueli) as a distinct species of ornithomimid related to Ornithomimus.