Struthiomimus

Struthiomimus is a genus of ornithomimid theropod dinosaurs from the Late Cretaceous period in western North America. The name means “ostrich mimic,” reflecting its ostrich-like body plan. The type species is Struthiomimus altus, and fossils have been found in formations that date to roughly 77 to 66 million years ago in present-day Canada and the United States.

Anatomy and appearance are characteristic of ornithomimids. Struthiomimus had a lightweight, elongated skeleton with a long neck, a small to moderate skull, and a toothless beak. The arms were short but stout, ending in three-fingered hands, while the hind limbs were long and powerful, built for speed. The tail was long and stiff, contributing to balance. Overall, the animal possessed a slender, bird-like build.

Size estimates place Struthiomimus at about 3 meters in length, with a body mass likely around a few dozen to over a hundred kilograms. Its limb proportions and foot structure indicate it was well adapted for rapid running, a trait common to many ornithomimids.

Paleobiology and ecology suggest a versatile, possibly omnivorous diet. The beak and dentition in related forms imply cropping vegetation, insects, and small animals may have been consumed. The animal likely relied on speed to escape predators and may have lived in social groups, as indicated by trackways and fossil associations with other dinosaurs. In its ecosystem, Struthiomimus coexisted with hadrosaurs, ceratopsians, and large theropods, occupying an open, terrestrial niche in North American floodplain environments.