Eodromaeus: Research Database
Dinosauria (Theropoda/Prondentia) · Late Triassic (~231–229 MYA) · South America — Argentina (Ischigualasto-Villa Unión Basin)
Research Note: Eodromaeus was one of the earliest known dinosaurs from the Late Triassic of Argentina. As a member of the earliest radiation of dinosaurs, it provides critical data on the diversification of dinosaurs in the Triassic and the evolutionary relationships between theropods and other dinosaur groups.
| Research Finding | Status | Grade | Year | Method | Citation | Impact |
|---|---|---|---|---|---|---|
|
Martínez et al. 2011: Eodromaeus from the Triassic of Argentina and early dinosaur diversification
Martínez et al. 2011 provide comprehensive data on Eodromaeus from the Late Triassic Ischigualasto-Villa Unión Basin of Argentina, establishing it as one of the earliest known dinosaurs and documenting its significance for understanding early dinosaur diversification in the Triassic
|
Confirmed | A | 2011 | Fossil | Martínez et al., ZooKeys | Taxonomy |
|
Césari et al. 2016: Paleoenvironment and biota of the Triassic of Argentina
Césari et al. 2016 provide additional data on the paleoenvironment and biota of the Triassic of Argentina, contextualising Eodromaeus within the broader ecological context of the earliest dinosaur ecosystems
|
Confirmed | B | 2016 | Fossil | Césari et al., Palaeogeography, Palaeoclimatology, Palaeoecology | Paleoenvironment |
Active Debate: The Earliest Dinosaur Diversification and the Origin of Major Dinosaur Groups
Whether Eodromaeus is a basal theropod or a more basal dinosaur is debated.
What We Still Do Not Know About Eodromaeus
- Complete skeletal morphology: Partial specimen known.
- Body mass: Estimated.
- Feather integration: Unknown (earliest dinosaur).
- Social behavior: No direct evidence.
In Depth
Eodromaeus is a very exciting find as it may well represent one of the earliest theropods. First thought to have been more fossils of Eoraptor, study by Paul Sereno revealed features not present in Eoraptor. With the fossils realised as a new dinosaur, the fossil description was published with the name Eodromaeus, a name referencing its early entry in the fossil record at the ‘dawn of the dinosaurs’.
As a theropod, Eodromaeus was bipedal, with smaller fore limbs terminating in hands. The hands of Eodromaeus display the transition from five digits to three, with the fourth and fifth digits being much smaller than the first three.
Further Reading
Further reading- A basal dinosaur from the dawn of the dinosaur era in southwestern Pangaea. Science 331(6014):206-210. – R. N. Martinez, P. C. Sereno, O. A. Alcober, C. E. Colombi, P. R. Renne, I. P. Monta�ez & B. S. Currie – 2011.
