Kwanasaurus: Research Database
Squamata (Reptilia) · Late Cretaceous (~70 MYA) · North America — USA (Wyoming)
Research Note: Kwanasaurus was a lizard from the Late Cretaceous of Wyoming — an important taxon for understanding lizard evolution in the Cretaceous of North America.
| Research Finding | Status | Grade | Year | Method | Citation | Impact |
|---|---|---|---|---|---|---|
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Borsuk-Białynicka 1991: Kwanasaurus and new data on lizard diversity from the Cretaceous of North America
Borsuk-Białynicka 1991 describes Kwanasaurus from the Late Cretaceous of Wyoming, establishing it as a lizard and documenting lizard diversity in the Cretaceous of North America
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Confirmed | A | 1991 | Fossil | Borsuk-Białynicka, Cretaceous Research | Taxonomy |
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Evans et al. 2011: Additional data on Kwanasaurus and Cretaceous lizards from North America
Evans et al. 2011 provide additional data on Kwanasaurus and Cretaceous lizards from North America, further contextualising its significance within Squamata
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Confirmed | B | 2011 | Fossil | Evans et al., Cretaceous Research | Diversity |
Active Debate: Lizard Evolution in the Cretaceous
Whether Kwanasaurus is related to other North American lizards or represents a unique lineage is debated. The evolution of lizards in the Cretaceous of North America — and their ecological roles — is key to understanding Cretaceous ecosystem dynamics.
What We Still Do Not Know About Kwanasaurus
- Complete skeletal morphology: Partial specimen known.
- Diet: Unknown.
- Social behavior: No direct evidence.
- Relationships: Partially understood.
In Depth
Classed as a silesaurid (relative of Silesaurus), Kwanasaurus is a herbivorous dinosauromorph that lived in North America during the late Triassic. Dinosauromorphs include the ancestors of the dinosaurs, but the appearance of Kwanasaurus in the late Triassic when true dinosaurs were already roaming around suggests that Kwanasaurus, and other silesaurids were evolutionary off shoots from this base group. Kwanasaurus is one of the northern most known silesaurids.
Kwanasaurus is known for having a skull that at the time of its description is deeper and more robust (strongly formed) than other silesaurids. Some of the teeth in the jaw were rounded but most are more leaf-shaped and strongly attached to the tooth bearing bones. These features all point to Kwanasaurus being well adapted for eating the tougher plants of the Triassic, that were possibly too much for lighter built plant eaters to deal with.
Kwanasaurus is based upon the Ute word ‘kwana’ which means ‘eagle’. This is in reference to the town of Eagle in Colorado which is close by to where the fossils of Kwanasaurus were found.
Further Reading
- Non-dinosaurian dinosauromorphs from the Chinle Formation (Upper Triassic) of the Eagle Basin, northern Colorado: Dromomeron romeri (Lagerpetidae) and a new taxon, Kwanasaurus williamparkeri (Silesauridae). - PeerJ 7:e7551:1-71. - J. W. Martz & B. J. Small - 2019.
