First maxilla of a late Miocene hominid from Thailand and the evolution of pongine derived characters

摘要: Abstract The evolutionary history of Asian Miocene hominids (great apes and humans) remains poorly documented, obscuring the ancestry orangutan (Pongo). Khoratpithecus from middle late Thailand Myanmar was previously documented only by mandibles isolated teeth. It has been interpreted as closest relative Pongo based on shared derived mandible characters such symphyseal morphology lack anterior digastric muscle scars. Here we describe a new maxilla, MFT-K176, which originates same sedimentary unit holotype piriyai in Nakhon Ratchasima province, Northeastern Thailand. maxilla displays unique subnasal with several being Sivapithecus Pongo, confirming its attribution to pongine clade. However, it differs other known dental morphology, showing more similar chiangmuanensis Metric similarities K. piriyai corroborate referral MFT-K176 Khoratpithecus. associated upper lower teeth would be required evaluate latter assertion conclusively, attribute provisionally cf. sp. Other anatomical clivus, palate molars are peculiar for this hominid but do not exclude sister group relationship Pongo. This plays pivotal role understanding that Ankarapithecus occupies basal position within clade supports exclusion Lufengpithecus