ornithomimids

Ornithomimids are a group of theropod dinosaurs within the larger lineage Ornithomimosauria, commonly referred to as “ostrich dinosaurs” for their bird-like build. The name means “bird mimic.” They lived during the Cretaceous period, with fossils found in North America, Asia, and Europe, ranging roughly from the Early to Late Cretaceous (about 125 to 66 million years ago).

Anatomy and appearance: Ornithomimids were characterized by a lightweight, elongate body, long legs, and a relatively small skull with a toothless or nearly toothless beak. They possessed long necks and highly agile limbs, with a tail that helped balance their speed. Their arms were relatively short with three-fingered hands. Evidence from fossils and feather impressions indicates they were likely feathered, a trait associated with many theropods.

Diet and behavior: Their exact diet is debated; most evidence points to omnivory or herbivory, with beaks well-suited for cropping vegetation and possibly scavenging or catching small animals. Their long legs and foot structure suggest they were fast runners, possibly among the faster theropods, which would have helped them escape predators and perhaps forage over large areas. Social behavior is not firmly established, but some trackways and nesting sites imply possible gregarious tendencies in certain species.

Taxonomy and diversity: The group includes several genera such as Ornithomimus, Gallimimus, Struthiomimus, and Dromiceiomimus. In some classifications, Struthiomimidae is treated as a separate family within Ornithomimosauria, but all are linked by their general body plan and beaked skulls.