Preliminary study on enamel microstructure of Yuanmou Miocene hominoids of China

Preliminary study on enamel microstructure of 5 lower permanent incisors of Late Mio-cene Yuanmou hominoids was conducted using a scanning electron microscope (SEM). The enamel incremental markings, as well as perikymata spacing and its periodicity were observed and counted. Using the perikymata number and periodicity, the crown formation times of the incisors are estimated. The transverse and longitudinal microstructures of the enamel prisms are also ob-served. Comparison of the dental development and enamel microstructure features of Yuanmou hominoids with those of Lufeng hominoids shows that there are similarities and also some differ-ences between them. The relationship between Yuanmou hominoids and early hominids is dis-cussed.