Gorgosaurus libratus

Last updated: May 27, 2024
Verified by: AZ Animals Staff
© Nick Fox/Shutterstock.com

Gorgosaurus probably lived and hunted in packs.


Gorgosaurus Scientific Classification

Scientific Name
Gorgosaurus libratus

Read our Complete Guide to Classification of Animals.

Gorgosaurus Conservation Status

Gorgosaurus Locations

Gorgosaurus Locations

Gorgosaurus Facts

Hadrosaurs, ankylosaurids, Lambeosaurus, Styracosaurus, and Centrosaurus
Main Prey
Hadrosaurs and ankylosaurids.
Group Behavior
  • Pack
Fun Fact
Gorgosaurus probably lived and hunted in packs.
Biggest Threat
Climate change and natural disasters
Most Distinctive Feature
Horn-like bumps on its head above each eye
Distinctive Feature
Round-shaped eyes
Woodlands, forest and plains
  • Pack
Favorite Food
Herbivores like hadrosaurs and ankylosaurids
Theropod dinosaur

Gorgosaurus Physical Characteristics

2–3 metric tons
26-30 feet

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Gorgosaurus was a tyrannosaurid theropod dinosaur that lived during the Late Cretaceous Period, between 76.6 and 75.1 million years ago. It was an earlier relative of the Tyrannosaurus rex. The heavily-built carnivore was an apex predator that preyed on ceratopsids and Hadrosaurus dinosaurs that lived in the same habitat. The Gorgosaurus is also one of the best-known specimens in the fossil record, with dozens of well-preserved specimens.

Description and Size

Gorgosaurus Mock-up

While it is related to the




is relatively smaller.

©Kendo Nice/Shutterstock.com

Lawrence Morris Lambe first described Gorgosaurus in 1914. Its name comes from the conjoining of two Greek words—”Gorgos,” meaning fierce or terrible, and “Saurus,” meaning lizard. Gorgosaurus is related to the Tyrannosaurus but relatively smaller.

An average adult of this dinosaur was about 26–30 feet from snout to tail, with an average weight of about 2–3 metric tons. The largest skull measured 39 inches. As opposed to other tyrannosaurid genera with oval or keyhole-shaped eye sockets, Gorgosaurus had a circular eye socket. There were horn-like bumps on its head above each eye. These bumps were mainly for display rather than fighting.  

Gorgosaurus had a closely crammed dental structure. The premaxillary teeth at the front of its mouth were stronger than the rest. Unlike other theropods, its teeth were not blade-like but oval-shaped. They had serrated edges that were extremely sharp, with posterior edges used to tear apart prey. Thanks to their massive jaw size and teeth, this dinosaur had a bite force of up to 42,000 Newtons. This is more than the T. rex‘s bite force of 35,000 Newtons.

The body structure of the Gorgosaurus was like that of a typical tyrannosaurid dinosaur. It had a massive head on an S-shaped neck. They were bipedal with relatively short forelimbs. The largest femur ever measured from this creature was 41 inches. Its tibia was longer and characteristic of a fast-running animal. The long and heavy tail of this dinosaur helped to balance the weight of its massive head.  

Diet — What Did the Gorgosaurus Eat?

Gorgosaurus was a carnivorous dinosaur. It sat at the top of the food chain and fed on other dinosaurs, including those that were relatively bigger. Many believe this dinosaur might have been cannibalistic too. 

The Gorgosaurus was a master hunter of its time, preferring to hunt in packs. Due to its growth pattern, hunting patterns differed at different stages, reducing food competition between adults and juveniles. The main prey of this dinosaur were herbivores like hadrosaurs and ankylosaurids. However, it probably fed on other plant-eating dinosaurs such as Lambeosaurus, Styracosaurus, and Centrosaurus. This dinosaur’s teeth had serrated edges that could cut through the flesh of their prey like a saw. 

Habitat — When and Where It Lived

Gorgosaurus lived in western North America about 76.6 to 75.1 million years ago. This was during the Campanian epoch of the Late Cretaceous. Experts think it occupied the same North American territory as Daspletosaurus, another tyrannosaurid dinosaur. Both dinosaurs would have been arch-enemies.

Its habitat consisted mainly of woodlands and forests since these areas held significant numbers of herbivores for prey. It also lived in the verdant floodplain environments along the edge of an inland sea. Since scientists found most of its fossils in Alberta, they believe this location had more dinosaurs than in any other territory. The climate of its habitat was subtropical, with marked seasonality and periodic droughts, which frequently resulted in vast mortality among the dinosaurs.

Threats and Predators

Gorgosaurus was an apex bipedal predator that preyed upon other herbivorous dinosaurs. Although it existed alongside Daspletosaurus, it remains unclear whether they competed for prey or if there was a differentiation in their ecological niches. Some researchers believe Gorgosaurus preyed more on faster dinosaurs while its peers hunted armored dinosaurs.

Like most of its stronger and fiercer cousins, Gorgosaurus dominated its native ecosystem along with other tyrannosaurids. It’s possible that the extinctions of other carnivores allowed Gorgosaurus and its counterparts to take over and dominate the woodlands and settle between 80 and 66 million years ago. Studies have shown that its predatory prowess was further heightened by the evolution of herbivores and the decline of the dominant carnivores that lived before it. It is also possible that they preyed on juveniles of their own species.

Discoveries and Fossils — Where Gorgosaurus Was Found

In 1913, Charles Stenberg discovered the holotype with a complete skeleton and skull. He made the find at the Dinosaur Park Formation of Alberta. It was the first fossil tyrannosaurid fossil with a hand. Today you can find it at the Canadian Museum of Nature, Ottawa.

Fossils of this dinosaur have been found deposited in luxuriant floodplains around the edge of the Western Interior seaway in North America. One of the most prominent specimens was discovered in a river ecosystem that shaped the Judith River Formation in Choteau County, Montana.

The Gorgosaurus specimen was preserved beneath fossilized plants and preserved by thick sands. The majority of the fossils have been discovered in Alberta, Canada. In fossil records, it is one of the best-represented tyrannosaurs, with 20 skeletons discovered so far. Fossilized tyrannosaurid teeth of the late Cretaceous of Montana, described as Deinodon by Joseph Leidy in 1856, were later found to belong to the Gorgosaurus

In 1917, Stenberg also found a fossil with a lower, lighter skull and more elongated limb proportions. It was noted that it had the features of juvenile G. libratus. Dozens of other specimens have been excavated over the years and are housed in different museums in the US and Canada. One of the largest samples in existence was discovered in Montana in 2018. In July 2022, the ancient skeleton sold at a Sotheby’s auction for six million dollars. 

Extinction — When Did It Die Out? 

The Gorgosaurus lived during the Late Cretaceous and might have disappeared shortly before the Cretaceous Period ended 66 million years ago. If it persisted till the end of the Cretaceous, then it probably died off with the rest of the land-dwelling dinosaurs during the Cretaceous-Tertiary extinction event

Similar Animals to the Gorgosaurus

Similar Animals to Gorgosaurus include:

  • Albertosaurus — Scientists once confused fossils of the Gorgosaurus for an Albertosaurus. They existed around the same time and were both top predators during their time. Albertosaurus was a tyrannosaurid dinosaur with powerful legs, a large head, and short arms.
  • Daspletosaurus — This was another tyrannosaurid that lived during the Late Cretaceous. It was about 30 feet which means it was roughly the same size as the Gorgosaurus. Both dinosaurs lived alongside each other. 
  • Tyrannosaurus rex — The T. rex is one of the most iconic dinosaurs. This theropod dinosaur lived in western North America about 66 million years ago. Although it looked similar to the Gorgosaurus, the T. rex was significantly bigger. 

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About the Author

Abdulmumin is a pharmacist and a top-rated content writer who can pretty much write on anything that can be researched on the internet. However, he particularly enjoys writing about animals, nature, and health. He loves animals, especially horses, and would love to have one someday.

Gorgosaurus FAQs (Frequently Asked Questions) 

When was the Gorgosaurus alive?

Gorgosaurus lived during the Campanian Epoch of the Late Cretaceous Period. This was between 76.6 and 75.1 million years ago.


How big was the Gorgosaurus?

An adult Gorgosaurus would have been between 26 to 30 ft in length from snout to tail. They weighed between 2–3 tons. This means their size would have been roughly the same as that of the Albertosaurus and Daspletosaurus but smaller than the Tyrannosaurus.

What did the Gorgosaurus look like?

The Gorgosaurus was a bipedal dinosaur with short arms and thick hind limbs. It had an enormous head balanced on an S-shaped neck. The dinosaur also had a heavy tail that served as a counterweight.

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