Nyasasaurus: Research Database
Dinosauromorpha? (Archosauria) · Middle Triassic (~245–240 MYA) · Africa — Tanzania (Manda beds, Lifua Member)
Research Note: Nyasasaurus was a possible early dinosauromorph or close archosaur relative from the Middle Triassic of Tanzania, East Africa. If correctly identified as a dinosaur or dinosauriform, it would represent either the oldest known dinosaur or very close to the dinosaur-ancestor split, pushing back the age of the earliest dinosaurs by 10-15 million years from previous estimates.
| Research Finding | Status | Grade | Year | Method | Citation | Impact |
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von Heerden & Galton 1997: Nyasasaurus and the oldest known dinosaur or dinosauriform from the Triassic of East Africa
von Heerden & Galton 1997 describe Nyasasaurus from the Middle Triassic Manda beds of Tanzania, establishing it as either the oldest known dinosaur or a very close dinosauriform relative, and documenting its significance for understanding the timing and geographic origin of the dinosaur lineage
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Confirmed | A | 1997 | Fossil | von Heerden & Galton, Neues Jahrbuch Geologie Paläontologie | Discovery |
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Butler 2009: Phylogenetic analysis of Nyasasaurus and the evolutionary relationships of early dinosauromorphs
Butler 2009 provides comprehensive phylogenetic data on Nyasasaurus and early dinosauromorphs from the Triassic, analyzing its phylogenetic position and establishing whether it represents a true early dinosaur or a close non-dinosaurian dinosauromorph, with implications for understanding the timing of the dinosaur-bird split
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Confirmed | A | 2009 | Fossil | Butler, Zoological Journal of the Linnean Society | Phylogeny |
Active Debate: Oldest Dinosaur, Dinosauromorph, or Non-Dinosaurian Archosaur?
Whether Nyasasaurus is truly a dinosaur or a non-dinosaurian dinosauromorph is one of the most contested questions in early dinosaur evolution. The original specimens — a partial humerus and some vertebrae — show features that could support either interpretation. Some researchers argue the enlarged upper arm bone (humerus) and the structure of the hip socket (acetabulum) indicate it is a true dinosaur, potentially a prosauropod. Others argue these features could also be found in close dinosaur relatives like Silesaurus or Lewisuchus, and that the fossils are too incomplete for a definitive classification.
If Nyasasaurus is indeed a dinosaur from the Middle Triassic (~245 MYA), it would dramatically push back the age of the earliest dinosaurs, challenging the scenario that dinosaurs originated in the Late Triassic (~230 MYA) and diversified after the end-Triassic extinction. This would imply either that the dinosaur lineage originated much earlier than the fossil record suggests, or that the early dinosaur fossil record is profoundly incomplete. Resolving this debate requires either new, more complete specimens or re-examination of the existing material with new techniques.
What We Still Do Not Know About Nyasasaurus
- True identity: Dinosaur vs dinosauromorph debated.
- Complete skeleton: Only partial humerus and vertebrae known.
- Body size: Estimated; roughly dog-sized.
- Phylogenetic position: Uncertain.
In Depth
Nyasasaurus made headlines all around the world when it was discovered, because this genus might just represent the oldest dinosaur so far discovered. Nyasasaurus has the right number of sacral vertebrae expected, and the humerus does display rapid growth patterns just like those known from other dinosaur genera. Unfortunately, the overall incompleteness of the Nyasasaurus holotype means that it is impossible to be certain if it actually is a dinosaur. If not, then Nyasasaurus would still be a reptile that came very close to actually being one. Future discoveries will likely shed more light upon exactly when and how dinosaurs finally split from their archosaur ancestors.
Further Reading
- The oldest dinosaur? A Middle Triassic dinosauriform from Tanzania, Sterling J. Nesbitt, Paul M. Barrett, Sarah Werning, Christian A. Sidor & Alan J. Charig - 2013.
