Ornithomimorpha

Ornithomimorpha is a clade of theropod dinosaurs that lived during the Cretaceous period. The name Ornithomimorpha means "bird mimics" due to their superficial resemblance to modern ostriches and other large flightless birds. They are characterized by several shared derived traits, including long legs, slender bodies, small heads, and elongated necks. These dinosaurs are often referred to as "ostrich dinosaurs" because of their appearance.

Fossil evidence for Ornithomimorpha has been found on various continents, suggesting a widespread distribution. They were likely bipedal and possessed adaptations for running, indicating they were probably agile and fast-moving. Their diet is a subject of debate among paleontologists. While some species may have been herbivorous or omnivorous, evidence from gut contents and tooth morphology in some related groups suggests that at least some ornithomimids were primarily herbivorous, feeding on plants, fruits, and seeds. Others might have supplemented their diet with insects or small vertebrates.

Ornithomimorpha is part of the broader group Ornithomimosauria, which itself is a subgroup within the larger theropod lineage. Key members of Ornithomimorpha include dinosaurs like Ornithomimus, Struthiomimus, and Gallimimus. The evolutionary relationships within this group are still being refined through ongoing research and new fossil discoveries. Their unique adaptations and evolutionary position make them an important component of Cretaceous ecosystems.