DinoVerse · Dinosaur fact sheet
Theropods

Gallimimus

Say it: GAL-ih-MY-mus  ·  Name means: “Chicken mimic”

Scientific life reconstruction of Gallimimus: Life restoration of the large Late Cretaceous ornithomimid Gallimimus bullatus.
Key facts about Gallimimus
⏳ Lived71–69 million years ago
Late Cretaceous
🍽️ DietOmnivore (eats plants and meat)
📏 Length5–6 m (16–20 ft)
↕️ Height1.7–1.9 m (6 ft)
⚖️ Weight400–490 kg (880–1,080 lb)
📍 Found inAsia
🔎 Discovered1963 by Polish-Mongolian expedition (named by Halszka Osmólska, Ewa Roniewicz and Rinchen Barsbold in 1972)

About Gallimimus

Gallimimus looked like a giant ostrich with a long tail. It was one of the fastest runners of the dinosaur world.

Gallimimus bullatus was the largest well-known ornithomimid, an 'ostrich-mimic' theropod from the Late Cretaceous Nemegt Formation of Mongolia. Its toothless beak, long neck and long, slender legs suggest a fast-running omnivore that ate a mix of plants and small animals.

How big was it?

Gallimimus: ~5.5 m longPerson 1.7 m · School bus 12 m
Compare with other dinosaurs →

Drawn to scale next to a 1.7 m adult and a 12 m school bus.

Did you know?

  1. Gallimimus had no teeth, just a beak, like a bird.
  2. Its long legs made it super fast, maybe as fast as a racehorse.
  3. It was about as tall as a grown-up and as long as a car.
  4. Its name means 'chicken mimic', because its neck reminded scientists of a chicken's.
  1. The first fossils were collected in the 1960s by Polish-Mongolian expeditions, and in 1972 it was named for features of its neck vertebrae that resemble those of a chicken.
  2. Running speed estimates for ornithomimids vary, but their long lower legs and light build suggest top speeds in the range of large running birds.
  3. A 2001 study suggested comb-like structures inside the beak were used to filter food from water like a duck, but later work found they were more like the ridges in a turtle's or plant-eating bird's beak.
  4. Close relatives such as Ornithomimus are preserved with feathers, so Gallimimus was very likely feathered too, though direct feather fossils for it have not been found.
DinoVerse · Gallimimus fact sheet
Theropods

🍽️ What did it eat?

Food: plants, seeds, insects, small lizards, small mammals, eggs.

Pecked and snipped food with a long, toothless beak; it may also have swallowed stones to help grind tough plants in its gizzard, like an ostrich.

Clues scientists use: toothless beak; gizzard stones found with close relatives; long neck and grasping hands suited to picking food.

Who might have hunted it: Tarbosaurus.

🗺️ Where fossils were found

  • Nemegt Formation, Gobi Desert, Mongolia (Asia)
  • Bugin Tsav, Gobi Desert, Mongolia (Asia)
Skeleton / museum mount of Gallimimus: Gallimimus bullatus in the Natural History Museum of London
Skeleton / museum mount of Gallimimus: Gallimimus bullatus in the Natural History Museum of London

Myth or fact?

✗ Myth: Gallimimus ran around in huge herds escaping big predators.

✓ Fact: Some related ornithomimids are found in groups, so herding is possible, but there is no direct fossil evidence of large Gallimimus herds.

✏️ Quick quiz

Circle the right answer. Name: ______________________

  1. Which living bird does Gallimimus look most like?

    • A Ostrich
    • B Penguin
    • C Parrot
    • D Owl
  2. What did Gallimimus have instead of teeth?

    • A Tusks
    • B Bony plates
    • C A beak
    • D Fangs
  3. Which big predator lived alongside Gallimimus in Mongolia?

    • A Spinosaurus
    • B Tarbosaurus
    • C Allosaurus
    • D Carnotaurus

Answers: 1–A 2–C 3–B

Sources and picture credits