Palaeontological evidence for an Oligocene divergence between Old World monkeys and apes
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Summary
This summary is machine-generated.The oldest fossil apes and Old World monkeys, dating back 25.2 million years, have been discovered in Tanzania. These significant fossil finds fill crucial gaps in early catarrhine evolution and primate history.
Area Of Science
- Paleontology
- Primate Evolution
- African Paleoecology
Background
- The early evolutionary history of apes and Old World monkeys in Africa is poorly understood.
- Fossil evidence for crown catarrhines older than 20 million years is scarce, contrasting with molecular divergence estimates.
- This has led to the hypothesis of long 'ghost lineages' for both Cercopithecoidea (Old World monkeys) and Hominoidea (apes).
Purpose Of The Study
- To describe the oldest known fossil ape and the oldest stem member of the Old World monkey clade.
- To extend the fossil record of catarrhines into the Oligocene epoch.
- To investigate potential links between catarrhine diversification and Oligocene African landscape changes.
Main Methods
- Paleontological excavation and analysis of fossilized primate remains.
- Precise radiometric dating of fossil-bearing strata.
- Comparative dental morphology analysis to determine phylogenetic placement.
Main Results
- Discovery of the oldest fossil ape, a partial mandible with 'nyanzapithecine' stem hominoid features.
- Discovery of the oldest stem Old World monkey, a lower third molar.
- Both fossils precisely dated to 25.2 million years ago from the Rukwa Rift, Tanzania.
Conclusions
- These discoveries push back the fossil record of apes and Old World monkeys into the Oligocene.
- The findings suggest catarrhine diversification may be linked to tectonic activity and landscape changes in the East African Rift system.
- The fossils provide critical new data for understanding early primate evolution in Africa.