Siamopithecus eocaenus, Anthropoid Primate from the Late Eocene of Krabi, Thailand

  • Yaowalak Chaimanee
Part of the Developments in Primatology: Progress and Prospects book series (DIPR)


An overview of the available remains of the Thai Late Eocene primate Siamopithecus eocaenus led to the conclusion that the species is an anthropoid, a group which is now documented in Asia since the Middle Eocene. Its remains have been collected from Krabi coal mine in Peninsular Thailand, deposited in a tropical fresh water swamp. Siamopithecus is a large primate, of body size estimated between 8 kg to 9 kg, displaying many shared derived dental characters with other Asian taxa such as Fondaungia, Amphipithecus, and Myanmarpithecus justifying its inclusion among the amphipithecids. From the available evidence, the anthropoid status of Siamopithecus is indisputable. However, it may be the sister-group of African and Arabian propliopithecids or similarities between Siamopithecus and propliopithecids may be the result of convergent evolution in a lineage of primitive Asian anthropoids related to Eosimias and Bahinia. Additional fossils are necessary to solve its phylogenetic affinities and to add additional information relative to the circumstances and the paleoenvironments that have led to its highly derived characters. Recently (2001) proposed to attribute Pondaungia to notharctine adapiforms on the basis of postcranial characters. As these elements have not been found in association with Pondaungia remains, their allocation to that genus remains problematic.


Middle Eocene Late Eocene Occlusal View Main Cusp Anthropoid Primate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer Science+Business Media New York 2004

Authors and Affiliations

  • Yaowalak Chaimanee
    • 1
  1. 1.Paleontology Section, Geological Survey DivisionDepartment of Mineral ResourcesBangkokThailand

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