Gallimimus: The Swift Runner of the Late Cretaceous

In the vast and diverse world of dinosaurs, the Gallimimus holds a unique place. Known for its bird-like features and swift agility, this dinosaur from the Late Cretaceous period has intrigued paleontologists and dinosaur enthusiasts alike. The name, meaning ‘chicken mimic’, is a nod to its resemblance to modern-day birds–a fascinating link between the ancient and the present.

The Gallimimus was built for speed with its long legs and lightweight body. Its adaptability and survival instincts are reflected in its physical characteristics, making it a remarkable specimen in the study of dinosaurs. This dinosaur is not just a relic of the past but a key to understanding the evolutionary journey of life on Earth.

Key facts

Gallimimus pronunciationGAL-ih-MIME-us
Meaning of nameChicken mimic
Type SpeciesGallimimus bullatus
When it Lived93.5 to 70.60 MYA
PeriodLate Cretaceous
EpochMiddle Turonian to Late/Upper Campanian
Length20 ft
Height6.0 ft at hips
Weight440-970 lbs
MobilityMoved on two legs
First Discovery1963 by Zofia Kielan-Jaworowska
Location of first findGobi Desert, Mongolia
First Described by1972 by Rinchen Barsbold
HolotypeIGM 100/11

Gallimimus Origins, Taxonomy and Timeline

"An illustration of Gallimimus, a fast-moving, ostrich-like dinosaur from the Late Cretaceous period. Gallimimus was a bipedal omnivore, characterized by its long legs, tail, and neck, which allowed it to run swiftly across its habitat.

The name Gallimimus, meaning ‘chicken mimic’, is derived from the Latin ‘gallus’, meaning chicken, and the Greek ‘mimos’, meaning mimic. This name reflects its bird-like physical characteristics, which are a fascinating link between the ancient and the present.

In terms of taxonomic classification, Gallimimus belongs to the group of theropods, a group of bipedal dinosaurs. Specifically, it is part of the family Ornithomimidae, known for their bird-like features and swift agility. Its type species is Gallimimus bullatus and this is the only species in the genus.

The Gallimimus lived during the Late Cretaceous period, specifically during a time when dinosaurs were the dominant terrestrial vertebrates. This dinosaur was among the last of their kind before the Cretaceous–Paleogene extinction event.

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Discovery & Fossil Evidence

The first fossil was discovered in 1963 by Zofia Kielan-Jaworowska, a Polish paleontologist, in the Gobi Desert of Mongolia. Since then, several other fossils have been found in the same region, indicating that Gallimimus was quite common in that area during the Late Cretaceous period.

A mounted skeleton of Gallimimus on display in a museum. This Late Cretaceous dinosaur is known for its long neck, beak-like mouth, and lightweight, agile frame. Gallimimus was a fast-running bipedal omnivore, measuring about 6 meters in length, and had a distinctive ostrich-like appearance.
Firsfron at en.wikipedia, CC BY-SA 3.0, via Wikimedia Commons

The fossils found include partial skeletons and skull fragments, providing valuable insights into the physical characteristics and lifestyle of this dinosaur. Notably, a nearly complete skeleton found in 1972 has been instrumental in our understanding of this unique dinosaur.

Gallimimus Size and Description

This was a dinosaur built for speed. With its long legs and lightweight body, it was likely one of the fastest dinosaurs of its time.

Short description of Gallimimus

Its body shape was streamlined, with a long neck and a small, toothless head, similar to modern ostriches. The Gallimimus had a long, stiff tail that likely served as a counterbalance during fast chases. Its limbs were long and slender, with three-fingered hands and four-toed feet, the latter equipped with a hoof-like structure for better traction. The Gallimimus moved on two legs–a characteristic of theropods–and its estimated speed could reach up to 30 miles per hour.

Size and Weight of Type Species

Size comparison of Gallimimus bullatus with a human, showcasing the dinosaur's approximate 6-meter length and 1.8-meter height. Gallimimus bullatus was a fast-running bipedal omnivore from the Late Cretaceous period, known for its long neck, beak-like mouth, and ostrich-like appearance.
PaleoGeekSquared, CC BY-SA 4.0, via Wikimedia Commons

This was a medium-sized dinosaur. Adult specimens could reach lengths of up to 20 feet and stand at a height of about 6 feet at the hips. The weight is estimated to be around 440-970 lbs, making it a lightweight dinosaur compared to many of its contemporaries. These estimates are based on the fossil evidence available, and it’s important to note that individual sizes could have varied.

The Dinosaur in Detail

The Gallimimus is a testament to the adaptability and survival instincts of dinosaurs. Its bird-like features, such as its long neck and toothless beak, set it apart from many other dinosaurs of its time. These features not only allowed it to move swiftly but also to forage effectively, making it a successful omnivore.

One of the most notable specimens is the nearly complete skeleton found in 1972. This specimen has provided invaluable insights into the dinosaur’s physical characteristics and lifestyle. It has also shed light on the dinosaur’s unique adaptations, such as its long, slender limbs and stiff tail, which were key to its speed and agility. This dinosaur and others of its family were almost certainly feathered dinosaurs. 

The Gallimimus in its Natural Habitat

Illustration of Gallimimus, a large, fast-running bipedal dinosaur from the Late Cretaceous period. Gallimimus is characterized by its long neck, beak-like mouth, and ostrich-like body. It was an omnivore, known for its speed and agility, which helped it evade predators and forage for food.
I, Steveoc 86, CC BY-SA 3.0, via Wikimedia Commons

This dinosaur lived during the Late Cretaceous period, a time when the Earth was warm and sea levels were high. It inhabited what is now the Gobi Desert in Mongolia, which back then was likely a semi-arid environment with seasonal rains. The landscape was likely dotted with rivers and lakes, providing ample water sources for the Gallimimus and other dinosaurs.

As an omnivore, this dinosaur had a diverse diet. It likely fed on plants, small animals, and possibly eggs. Its long neck and toothless beak would have allowed it to forage effectively, while its speed would have helped it escape from predators.

It was a bipedal dinosaur that moved swiftly on its two hind legs. This mode of locomotion, combined with its lightweight body and long legs, would have made it a fast and agile creature, capable of quickly escaping danger or chasing after prey.

Interesting Points about Gallimimus

  1. It is known for its bird-like features, earning it the name ‘chicken mimic’.
  2. It was one of the fastest dinosaurs, with estimated speeds of up to 30 miles per hour.
  3. This dinosaur was an omnivore, a trait that is relatively rare among theropods.
  4. Its long, stiff tail likely served as a counterbalance during fast chases.
  5. A nearly complete skeleton found in 1972 has provided invaluable insights into this unique dinosaur.

Contemporary Dinosaurs

In the vast expanse of prehistoric time, this dinosaur found itself in a world teeming with diverse life forms. Among these were the Tarbosaurus, Velociraptor, Oviraptor, and Protoceratops–each playing a unique role in the intricate ballet of survival.

The Tarbosaurus, a creature of formidable size and strength, might have been a source of danger for the Gallimimus. This towering predator’s powerful jaws and sharp teeth provided a stark contrast to the nimble and quick Gallimimus. Yet, the Gallimimus might have often eluded the clutches of the Tarbosaurus, turning the predator-prey dynamic into a thrilling chase across the prehistoric landscape.

The Velociraptor and Oviraptor, smaller but no less significant, added another layer of complexity to the Gallimimus’s existence. These dinosaurs were known for their cunning and agility and might have posed a different kind of threat. The Gallimimus, despite being larger, would have had to rely on its keen senses and swift reactions to avoid becoming prey.

Lastly, the herbivorous Protoceratops might have been a competitor for resources rather than a threat. The Gallimimus, with its ability to switch between a bipedal and quadrupedal stance, might have had an advantage in reaching for the higher vegetation, thus reducing the competition.

In this vibrant and dynamic world, the Gallimimus navigated its existence by interacting with its contemporaries in a myriad of ways. These interactions, whether they were chases with the Tarbosaurus, evasion of the Velociraptor and Oviraptor, or competition with the Protoceratops, shaped the Gallimimus’s existence and paint a vivid picture of its life in the prehistoric world.

List Of All Dinosaurs

We have created a list of all dinosaurs we have covered here, sorted across the seven main groups of dinosaurs. We also include information about their type of diet, (omnivore, herbivore or carnivore) and the time they lived.

Frequently Asked Questions

What does the name mean?

The name means ‘chicken mimic’, reflecting its bird-like physical characteristics.

When did the Gallimimus live?

It lived during the Late Cretaceous period, specifically between 70 to 66 million years ago.

What did this dinosaur eat? 

It was an omnivore, meaning it likely ate both plants and small animals as well as eggs.

How fast could it run?

The Gallimimus was likely one of the fastest dinosaurs, with estimated speeds of up to 30 miles per hour.

Where were fossils found?

Fossils have been found in the Gobi Desert in Mongolia.


Please note that the information in this article is based on various sources, drawing on scientific research, fossil evidence, and expert analysis. The aim is to provide a comprehensive and accurate overview of the Gallimimus, but please be aware that our understanding of dinosaurs and their world is constantly evolving as new discoveries are made.

This article was last fact-checked: Joey Arboleda, 06-11-2023

Featured Image Credit: Steveoc 86, CC BY-SA 3.0, via Wikimedia Commons