In September 2016 a team of Canadian paleontologists described a new species of ornithomimid, Rativates evadens, from the Dinosaur Park Formation of Alberta, Canada. The specimen was actually discovered in 1934 by paleontologist Levi Sternberg, and had been originally assigned to the species Struthiomimus altus, but a recent re-eximanation led by Brad McFeeters has demonstrated that it is not a specimen of Struthiomimus, nor any other known ornithomimid species.
The Dinosaur Park Formation was deposited in the late Campanian age of the Late Cretaceous Period approximately 75 million years ago, and is present in numerous locations in western Canada, most notibly, Dinosaur Provincial Park in Alberta. It preserves a diverse and well known assemblage of dinosaurs including predatory tyrannosaurs, duck-billed hadrosaurs, and horned ceratopsians, as well as several species of ornithomimid.
Rativates is based on a single partial skeleton made up of the front part of the skull, a complete left hindlimb, partial right hindlimb, pelvis, and several heavily eroded tail vertebrae. The specimen represents an animal that is smaller than most adult ornithomimids found in the Dinoaur Park Formation. The name Rativates evadens means "ratite foreteller [who] evades." The genus name references the fact that ornithomimids are often caled "ostrich mimics" even though ornithomimids lived millions of years before ostriches evolved so ostriches are in fact mimicing them. Additionally, evadens references both the dinosaur's ability to evade predators and this specimen's ability to evade recognition as a unique species.