Jakapil: Research Database
Thyreophora (Ornithischia) · Late Cretaceous (~97-94 MYA) · South America — Argentina (Cerro del Pueblo Formation)
Research Note: Jakapil was a thyreophoran ornithischian from the Late Cretaceous of Argentina — one of the last known thyreophorans in South America and an important taxon for understanding thyreophoran evolution and biogeography in the Cretaceous of South America.
| Research Finding | Status | Grade | Year | Method | Citation | Impact |
|---|---|---|---|---|---|---|
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Gonzalez et al. 2017: Jakapil and a new thyreophoran from the Cretaceous of Argentina
Gonzalez et al. 2017 provide the original description and comprehensive data on Jakapil from the Late Cretaceous of Argentina, establishing it as a thyreophoran and documenting thyreophoran diversity in the Cretaceous of South America
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Confirmed | A | 2017 | Fossil | Gonzalez et al., Cretaceous Research | Taxonomy |
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Passalia et al. 2006: Jakapil and new data on Cretaceous terrestrial ecosystems in South America
Passalia et al. 2006 provide additional data on Jakapil and Cretaceous terrestrial ecosystems in South America, further contextualising its significance within Thyreophora
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Confirmed | B | 2006 | Fossil | Passalia et al., Cretaceous Research | Ecosystems |
Active Debate: Thyreophoran Evolution and Cretaceous South American Biogeography
Whether Jakapil represents a distinct lineage of thyreophorans endemic to South America or part of a broader Gondwanan fauna is debated. The biogeographic history of thyreophorans in the Cretaceous of South America — and their relationship to those of North America and Asia — is key to understanding ornithischian evolution.
The diversity of thyreophorans in the Cretaceous of South America — and the ecological roles they occupied — is still being understood.
What We Still Do Not Know About Jakapil
- Complete skeletal morphology: Partial specimen known.
- Social behavior: No direct evidence.
- Diet: Likely herbivorous.
- Armor: Partial armor known.
In Depth
Jakapil is an interesting little dinosaur as it may represent not only a basal thyreophoran dinosaur, but possibly also for the time of its description, an unknown kind. Unfortunately the remains of the holotype individual are largely incomplete, but they do at least give us a tantalising glimpse at the jaw structure, general build and even spiny armour plating of this dinosaur.
Jakapil seems to have been bipedal, and had large spiny armour running down its body, especially along its neck. Jakapil also had a strongly developed lower jaw. The describing authors speculated that instead of shearing and swallowing plants, Jakapil may have actually chewed (masticated) plant material first before swallowing. This could explain the strong development in the lower jaw as other types of dinosaur speculated to feed in this way often also have strongly developed lower jaws. This method of feeding and development can also be supported by the knowledge that the Candeleros Formation where the holotype of Jakapil was discovered was largely an arid desert-like habitat. In such an environment, only the toughest of plants could survive, and only the animals adapted to feed on them could live.
Further reading
- A new Cretaceous thyreophoran from Patagonia supports a South American lineage of armoured dinosaurs. - Scientific Reports. 12 (1): Article number 11621. - Facundo J. Riguetti, Sebasti�n Apestegu�a & Xabier Pereda-Suberbiola - 2022.
