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July 30, 2026Short & citedBlog
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Field Notes • Paleontology

Brontosaurus

Brontosaurus is a genus of large, long-necked herbivorous sauropod dinosaurs from the Late Jurassic period of western North America.

Updated July 30, 20261 min readCited sources

Brontosaurus is a genus of large, long-necked herbivorous sauropod dinosaurs from the Late Jurassic period of western North America. The name means “thunder lizard,” and the genus has a complicated taxonomic history.

What it is

Brontosaurus was a massive quadrupedal dinosaur with a long neck and tail, living about 156 to 145 million years ago. It belonged to the family Diplodocidae and was one of the largest land animals of its time. Fossils are primarily found in the Morrison Formation of the western United States.

Why it matters

The taxonomic status of Brontosaurus has been debated for decades. For much of the 20th century, it was considered a synonym of Apatosaurus. However, later studies in the 2010s argued that Brontosaurus is a distinct genus, reviving the name and highlighting the complexity of dinosaur classification.

Key details

Brontosaurus was first described by Othniel Charles Marsh in 1879 from fossils found in 1874. Reported species include Brontosaurus excelsus, Brontosaurus yahnahpin, and Brontosaurus parvus. Estimates of its length vary, but it is commonly considered about 22 metres long.

In short

  • Brontosaurus was a large sauropod with a long neck and tail.
  • It lived in the Late Jurassic, about 156 to 145 million years ago.
  • For much of the 20th century, it was considered the same as Apatosaurus but later revived as a separate genus.
  • Fossils were first found in western North America in 1874 and described in 1879.
Canadian angle

Brontosaurus is mainly relevant to Canadian readers through museum collections, dinosaur education, and paleontology research, where it remains one of the best-known sauropod dinosaurs in public science communication.

Quick questions

What was Brontosaurus?
Brontosaurus was a genus of large, herbivorous sauropod dinosaurs that lived in the Late Jurassic period in western North America.
What does the name Brontosaurus mean?
The name Brontosaurus is commonly translated as “thunder lizard.”
Was Brontosaurus the same as Apatosaurus?
For much of the 20th century, Brontosaurus was treated as a synonym of Apatosaurus, but later studies argued that Brontosaurus should be recognized as a separate genus.

Sources

  1. Encyclopaedia Britannica — https://www.britannica.com/animal/Brontosaurus
    Supports: General description, age, discovery, and naming
  2. Natural History Museum — https://www.nhm.ac.uk/discover/brontosaurus-reinstating-a-prehistoric-icon.html
    Supports: Late Jurassic age and historical context
  3. iHeartDinosaurs — https://iheartdinosaurs.com/brontosaurus-facts/
    Supports: 2015 reclassification overview and species list
  4. The Fact Site — https://www.thefactsite.com/brontosaurus-facts/
    Supports: Name meaning and size estimates
  5. WorldAtlas — https://www.worldatlas.com/articles/brontosaurus-facts-extinct-animals-of-the-world.html
    Supports: Species list, family, and discovery details
  6. Active Wild — https://www.activewild.com/brontosaurus/
    Supports: Classification, species list, and extinction timing