Paleoichthyology in the Philippines: A review of Cenozoic fish fossils with insights on its current status and future opportunities

Systematic fish fossil studies are scarce in the tropical West Pacific, which hinders our understanding of historical processes that resulted in the modern fish fauna in the region. To fill this gap, we reviewed published and domestic fish fossil reports in the Philippines, assessed the status of paleoichthyological research, described fish fossil-bearing sedimentary basins and formations, highlighted difficulties, and provided prospects for future research opportunities. So far, six published documents have reported Oligocene to Pleistocene fish fossils from three sedimentary basins: Cagayan Valley Basin, Ilocos-Central Luzon Basin, and Visayan Sea Basin. Based on domestic reports, we have identified six additional stratigraphic units containing Miocene to Pleistocene fish fossils, such as skeletons, mouth plates, teeth, vertebrae, and otoliths. Moreover, we identified 58 fossiliferous units from eight sedimentary basins for future explorations. The lack of expertise, however, hinders the systematic sampling and study of fish fossils in the country. We recommend developing a national program for paleoichthyological research and promoting paleontology by engaging researchers, government agencies, private collectors, and the general public. This concerted effort will enhance our understanding of the paleoichthyological fauna of the Philippines, which is vital in bridging the knowledge gap on fish fossil records in the West Pacific region.