TROPICAL OSTRACOD DIVERSITY AND PALEOBIOGEOGRAPHY IN THE INDO-PACIFIC

The Southeast Asian shallow marine area situated between the Indian and Pacific Oceans currently exhibits incredible marine biodiversity, and is well known as the Coral Triangle or the Indo-Australian Archipelago (IAA) biodiversity hotspot. However, Cenozoic paleobiogeography of this region remains unclear except for larger benthic foraminifera, a relatively well-studied tropical taxon. We investigate Cenozoic history of the IAA hotspot using shallow marine Indonesian and Philippine ostracods (Crustacea) from the Mid-Miocene, Pliocene and Pleistocene. A diverse, extant class abundantly found and well-preserved in the fossil record, fossil ostracods may indicate community, habitat and environmental changes in the epochs examined. In Mid-Miocene outcrop samples, lower species diversity and fewer individuals were observed compared with those from the Plio-Pleistocene. Further work aims to determine potential factors or contributing mechanisms for this surge in diversity, and to investigate this increase at a finer time scale.