Gallimimus

Gallimimus is a genus of theropod dinosaurs in the family Ornithomimidae, from the Late Cretaceous period of what is now Mongolia. It lived roughly 70 to 66 million years ago. The name Gallimimus means “chicken mimic” or “bird mimic,” referring to its beaked face and presumed birdlike lifestyle. The type species is Gallimimus bullatus.

Discovery and description: Fossils of Gallimimus have been found in the Nemegt Formation of Mongolia. The genus was described in 1972 by Halszka Osmólska, Ewa Roniewicz, and Rinchen Barsbold. Several well-preserved specimens have contributed to our understanding of its anatomy and lifestyle.

Physical characteristics: Gallimimus was a slender, bipedal dinosaur with a long neck and a lightweight skull. It had very long hind limbs and a long, stiff tail for balance, adaptations associated with fast running. The skull carried a beak-like mouth, and most ornithomimids have few or no teeth. The animal was large for an ornithomimid, with estimates placing its length around 5 to 6 meters and a body mass in the several hundreds of kilograms. The forelimbs were relatively short and ended in three fingers.

Paleobiology: Most evidence suggests an omnivorous or herbivorous diet, with a specialization for speed that would aid in foraging and escape. Its limb proportions indicate high cursorial ability, and its beaked mouth suggests a range of plant materials and small prey could have been consumed. Ornithomimids, including Gallimimus, are commonly interpreted as bird‑like, fast-running theropods.

See also: Ornithomimidae, Theropoda, Nemegt Formation.