The Canadian Encyclopedia — neutral, cited, updated
July 26, 2026Sources cited
Canadianwire.
Canada’s encyclopedia & explainer
HomeScience & NaturePaleontologyTyrannosaurus
Science & Nature • Paleontology

Tyrannosaurus

Tyrannosaurus is a genus of large tyrannosaurid theropod dinosaurs from the Late Cretaceous of western North America.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

Tyrannosaurus is a genus of large tyrannosaurid theropod dinosaurs from the Late Cretaceous of western North America. The best-known species is Tyrannosaurus rex, one of the largest land predators known, with fossils found in the United States and Canada. The name means “tyrant lizard.”

Description

Tyrannosaurus was a giant bipedal predator with a heavy skull, strong jaws, and bone-crushing teeth. Sources describe it as one of the largest known carnivorous dinosaurs, with estimates varying by specimen. Tyrannosaurus had a large skull, powerful jaws, and about 60 serrated teeth.

Fossil record and range

Fossils are known mainly from western North America, including Canada and the United States. They occur in Late Cretaceous formations, and some isolated specimens may indicate an earlier origin than the main fossil record suggests. Tyrannosaurus fossils have been found in Alberta, making it directly relevant to Canadian paleontology and museum collections.

Species and classification

Tyrannosaurus is the genus that includes Tyrannosaurus rex, the best-known species. It belongs to Tyrannosauridae, a group of large theropod dinosaurs.

Ecology and behaviour

Tyrannosaurus was carnivorous and likely occupied the role of apex predator in its ecosystem. Evidence and reconstructions suggest it preyed on large herbivorous dinosaurs, though it may also have scavenged.

Scientific importance

Tyrannosaurus is one of the most studied dinosaurs because of the abundance and quality of its fossils. It is widely used in research on dinosaur growth, biomechanics, feeding, and evolution.

Key facts

  • Tyrannosaurus was a genus of large carnivorous theropod dinosaurs.
  • Its fossils come from Late Cretaceous rocks dated to about 69–66 million years ago.
  • It lived in western North America on the Laramidia landmass.
  • The best-known species is Tyrannosaurus rex.
  • Tyrannosaurus had a large skull, powerful jaws, and about 60 serrated teeth.
🍁
Canadian context

Tyrannosaurus fossils have been found in Alberta, making it directly relevant to Canadian paleontology and museum collections.

Frequently asked questions

What does Tyrannosaurus mean?
It means “tyrant lizard.”
Is Tyrannosaurus the same as T. rex?
No. Tyrannosaurus is the genus; Tyrannosaurus rex is the best-known species.
When did Tyrannosaurus live?
It lived in the Late Cretaceous, roughly 68 to 66 million years ago.
Where were Tyrannosaurus fossils found?
Fossils have been found in western North America, including Canada and the United States.
Was Tyrannosaurus a carnivore?
Yes. It was a large carnivorous theropod dinosaur.
How many teeth did Tyrannosaurus have?
Sources commonly describe Tyrannosaurus as having about 60 serrated teeth.

References

  1. Wikipediahttps://en.wikipedia.org/wiki/Tyrannosaurus
    Supports: Late Cretaceous age, western North American range, and mention of possibly earlier isolated specimens.
  2. Natural History Museumhttps://www.nhm.ac.uk/discover/dino-directory/tyrannosaurus.html
    Supports: Name meaning, classification as a large theropod, diet, tooth count, timing, and presence in Canada and the USA.
  3. Smithsonian Institutionhttps://www.si.edu/newsdesk/factsheets/tyrannosaurus-rex
    Supports: Name meaning and range in western North America during the Late Cretaceous.
  4. American Museum of Natural Historyhttps://www.amnh.org/dinosaurs/tyrannosaurus-rex
    Supports: Fossils in western North America, including Alberta, Canada, and size estimates.
  5. Encyclopaedia Britannicahttps://www.britannica.com/animal/tyrannosaur
    Supports: Tyrannosaurs as predatory theropods and Tyrannosaurus rex as the best-known and largest member of the group.