Dinosaurs A to Z
Ornithomimosauria

Gallimimus bullatus GAL-ih-MIME-us

"Chicken mimic"

Gallimimus silhouette
You 1.8 m (5.9 ft) tall
Gallimimus 6 m (19.7 ft) long
as long as 4 people standing fingertip to fingertip
silhouette · T. Michael Keesey (CC0) via PhyloPic
Length
6 m (19.7 ft) — About 6 m long, ~400 kg — ostrich-shaped.
Period
Late Cretaceous (70–69 Mya)
Place
Asia · Mongolia
Food
Omnivore — Probably plants, insects, small animals, and eggs — modern ostriches eat similarly.
Clade
Ornithomimosauria Dinosauria Saurischia Theropoda Coelurosauria Ostrich-mimic theropods, mostly toothless and fast.

The "chicken mimic": the largest ostrich dinosaur, built for running across the Gobi.

Gallimimus reconstruction by PaleoNeolitic
Reconstruction · PaleoNeolitic (CC-BY)

Gallimimus looked like a giant ostrich with a long tail. It had a toothless beak, big eyes, and long legs built for running. It was one of the fastest dinosaurs known — estimates put its top speed somewhere between 40 and 60 km/h. Gallimimus is the dinosaur Dr. Grant and the kids see running in a flock during Jurassic Park.

More about Gallimimus

Discovery

Named by Osmólska and colleagues (named the genus and species in 1972) · 1972 · Tsaagan Khushuu, in the Nemegt Basin of the Gobi Desert, Mongolia

Several fossils at various growth stages were collected by the Polish-Mongolian palaeontological expeditions to the Gobi Desert during the 1960s. The largest skeleton, found by Zofia Kielan-Jaworowska in 1964 lying on its back with its skull under its pelvis, later became the holotype of Gallimimus bullatus.

The generic name means "chicken mimic", referring to the similarities between its neck vertebrae and those of the Galliformes. The species name bullatus comes from bulla, a golden capsule worn by Roman youth, in reference to a bulbous structure at the base of the skull.

Zofia Kielan-Jaworowska. Polish palaeontologist who discovered the largest skeleton (later the holotype of Gallimimus bullatus) at Tsaagan Khushuu in 1964 during the Polish-Mongolian expeditions; the expeditions she was part of were notably led by women, some among the first women to name new dinosaurs.

Did <em>Gallimimus</em> have feathers?
No feathers are preserved on Gallimimus itself, so this is inference. Based on its relative Ornithomimus, which preserves quill-knobs on the ulna where feathers attached, it is considered highly likely that Gallimimus was feathered and that adults bore wing-like structures.
For the curious → How fast and how social was it?
As a bipedalWalking on two legs. coelurosaurThe theropod branch closest to birds — raptors, tyrannosaurs, ornithomimids. built for running (cursorial), its speed has been estimated at roughly 42-56 km/h (29-34 mph), used to escape predators. It may have lived in groups, an idea suggested by the discovery of several specimens together, and may have had vision and intelligence comparable to modern ratite birds.

What we know

  • One of the largest ornithomimosaurs — the 'ostrich dinosaurs'.
  • Toothless beak, suggesting a mixed diet of plants and small animals.
  • Long legs with proportions matching modern fast-running birds.
  • Many specimens known, from juveniles to adults.

What we guess

  • Whether it ate mostly plants, mostly small animals, or both.
  • Top running speed — estimates vary from 40 to 60 km/h depending on the bone-strength model.
  • Whether Gallimimus had simple feathers or filaments — almost certain but not yet preserved.