Siamopithecus: the first anthropoid

The fragmentary maxillofacial and mandibular remains of a Siamopithecus specimen from the Late Eocene Krabi formation, Thailand (approximately 40 million years ago) plays a key role in the investigation of early anthropoid evolution from lemuroid stem groups. Computer-assisted reconstruction of the deformed and compressed remains revealed a series of anthropoid features that is currently being checked against an extended sample of fossil and extant prosimian and simian specimens. Geometric-morphometric analysis focuses on quantitative features characterizing taxon-specific relationships between mandibular, maxillar and orbital morphology in prosimians and simians. This project is carried out in cooperation with Yaowalak Chaimanee (Geological Survey, Bangkok) and J.-J. Jaeger (University of Montpellier II).