Rativates

*Rativates evadens*

Rativates evadens is a genus of ornithomimid theropod dinosaur that lived in Alberta, Canada during the Late Cretaceous period around 76 million years ago. It is known from remains found in the Dinosaur Park Formation in Canada. The type and only species described is Rativates evadens.

## Description

The known specimen of Rativates was a subadult or adult individual of at least eight years of age, as demonstrated by examination of lines of arrested growth on a thin section of the right femur. It was small for an ornithomimid, being barely the 50% the size of the largest individuals of Struthiomimus .

The authors identified four autapomorphies, or derived unique traits, that distinguish Rativates from other ornithomimids: the part of the maxilla in contact with the jugal is relatively short and located posteroventrally; the tail vertebrae in front of the transition point (at which the tail vertebrae become abruptly thinner and elongated) have unusually short mound-shaped neural spines in horizontal view; the two halves of the ischium are entirely fused together, without any fissure between the right and left axes on its posterior surface; and the flexor edge of the third metatarsal is straight, not concave as in other ornithomimids.

Additionally, the authors also pointed out other features that distinguish it from other contemporary ornithomimids. Unlike Struthiomimus , the anterior part of the ilium extends forward until it reaches the end of the pubic shaft, and the medial edge of the third metatarsal is straighter. Compared to Ornithomimus , the antorbital fenestra is proportionally shorter. Finally, Rativates is smaller than an unnamed ornithomimid from Dinosaur Park, and also differs in the anatomy of its unguals.

## Discovery and naming

In 1934, Levi Sternberg discovered the skeleton of a small ornithomimid in Quarry No. 028 near the Red Deer River in the area of ​​present-day Dinosaur Provincial Park in Alberta, Canada. In 1950, he considered it to be a specimen of Struthiomimus . In 1972, Dale Alan Russell formally referred this specimen to Struthiomimus altus ; Russell partially based his reconstruction of S. altus on the skull of this specimen. The rest of the skeleton was not described until 2016.

In 2016, the type species Rativates evadens was named and described by Bradley McFeeters, Michael J. Ryan, Claudia Schröder-Adams, and Thomas M. Cullen. The name of the genus is derived from the Latin ratis , "raft", in reference to the group of birds Ratites, and vates , "seer", since the ornithomimids were like a harbinger of the future existence of the Ratites to which they resembled. The species name evadens means "evader" in Latin, referring to the animal's ability to run quickly to evade predators and also to having evaded recognition as a separate species for eighty years.

The holotype specimen, ROM 1790 , was found in a lower layer of the Dinosaur Park Formation, which dates to the late Campanian. This consists of a partial skeleton, including the snout, the front area of ​​the jaws, the last dorsal vertebra, six sacral vertebrae, fifteen front tail vertebrae that may or may not have formed a natural series, the complete pelvis, and the hind limbs (with the exception of the bottom of the right foot). Most of the bones are damaged and compressed. They are part of the collection of the Royal Ontario Museum.

## Classification

A phylogenetic analysis was performed based on a data set used in the description of an ornithomimid from Bissekty, Uzbekistan. In this analysis it was found that Rativates ended in a polytomy along with other advanced ornithomimids, which is consistent with a single radiation Evolution of ornithomimids on the ancient continent of Laramidia during the Campanian.

## Appearance in Jurassic Park and other media

### *Jurassic Park*

* Rativates appeared in the game Jurassic World: Alive.