Brachylophosaurus: Research Database
Hadrosauridae (Ornithischia) · Late Cretaceous (~80-77 MYA) · North America — USA, Montana (Judith River Formation)
Research Note: Brachylophosaurus was a hadrosaurid ornithischian from the Late Cretaceous of Montana — known from exceptionally preserved specimens including soft tissue and had one of the most distinctive hadrosaurid crests. As a member of the Hadrosauridae, it provides data on hadrosaurid diversity and the Cretaceous dinosaur faunas of North America.
| Research Finding | Status | Grade | Year | Method | Citation | Impact |
|---|---|---|---|---|---|---|
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Gates et al. 2009: Brachylophosaurus and hadrosaurid diversity in the Cretaceous of North America
Gates et al. 2009 provide comprehensive data on Brachylophosaurus from the Late Cretaceous of Montana, establishing it as a hadrosaurid and documenting hadrosaurid diversity in the Cretaceous of North America
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Confirmed | A | 2009 | Fossil | Gates et al., Cretaceous Research | Diversity |
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Hall et al. 2015: Brachylophosaurus and new data on hadrosaurid anatomy and paleobiology
Hall et al. 2015 provide additional data on Brachylophosaurus anatomy and paleobiology, further contextualising its significance within Hadrosauridae
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Confirmed | B | 2015 | Fossil | Hall et al., Journal of Vertebrate Paleontology | Anatomy |
Active Debate: Hadrosaurid Evolution and Cretaceous North American Biogeography
Whether the distinctive crest of Brachylophosaurus was used for display, species recognition, or thermoregulation is debated. The function of hadrosaurid cranial ornamentation is one of the classic questions in dinosaur paleobiology.
The diversity of hadrosaurids in the Cretaceous of North America — and their ecological relationships with ceratopsids and tyrannosaurids — is still being understood.
What We Still Do Not Know About Brachylophosaurus
- Complete skeletal morphology: Known from multiple specimens.
- Social behavior: Possible herding.
- Diet: Likely herbivorous.
- Color: Unknown.
In Depth
Brodavis was a genus of hesperornithiform that lived in both Asia and North America towards the end of the Cretaceous. Like relative genera, Brodavis would have dived below the water and used well developed feet to swim through the water after fish. What is perhaps most interesting though is that Brodavis was the first hesperornithiform bird that we knew of to have actually hunted in freshwater ecosystems rather than sea water.
Because the bones of Brodavis do not have the same level of pachyostosis (thickening of the bones) as other hesperornithiformes, the genus has been speculated to have some volant (flight) abilities. This is a plausible argument given the wide distribution of the genus and obvious advantage of being able to reach new bodies of freshwater. However, it should also be remembered that fresh water does not have the same level of buoyancy as salt water. Therefore, if Brodavis only hunted in freshwater, their bones would not need to be as dense as their salt water relatives in order to sink their bodies below the surface of the water.
Further Reading
- A new evolutionary lineage of diving birds from the Late Cretaceous of North America and Asia - Larry D. Martin, Evgeny N. Kurochkin & Tim T. Tokaryk - 2012.
