MAMMALIAN FAUNAS AND THE AGES OF THE CONTINENTAL TERTIARY FOSSILIFEROUS LOCALITIES FROM THAILAND

The paleontological study of the mammalian fossils of Tertiary fossili ferous localities from Thailand, has led to the description of numerou s new taxa, the modification of several extant paleobiogeographical pa tterns and identification of accurate dates for the Tertiary continent al basins. The Krabi Basin yielded 27 distinct mammal species, most of them representing new forms, and an Upper Eocene age is now well esta blished for this southern locality. The use of the Krabi assemblage as a reference fauna also led to the reassessment of the ages of several other Asian localities and suggests that the Thai assemblage lived in a forest under a tropical climate. All localities from northern Thail and occur in a time span ranging from 16 to 14 Ma. The use of the ceno gram method, allowed the paleoenvironment of the Neogene Thai localiti es to be compared with contemporaneous faunal communities from the Pak istan Siwaliks and China. The middle Miocene environment in South Asia seems to have been quite open, with a likely monsoonal climate. Final ly, the ages of different fossiliferous localities from Thailand are c orrelated with the geodynamic events following the India-Asia collisio n.