Fish fossils of Taiwan: a review and prospection

Despite the frequent occurrence of fish fossils in the field, related studies are noticeably rare in Taiwan. The scant fossil record of fish in the literature sharply contrasts the high diversity of modern fish in this region. This is often due to the scarcity of well-preserved materials, limited exposure that covers long geological ages, and lack of comprehensive sampling design. Over the years, unstudied new fish fossils have been collected and accumulated. Several old and published specimens stored in private collections are lost. In this study, we evaluated potential horizons yielding fish fossils, examined the current status of published specimens with updated regional stratigraphic correlation, and finally explored possible directions for future work. Our extensive bibliographic reviews revealed a total of published 47 taxa, which are mostly in the form of teeth (elasmobranch) and otoliths (teleost). Skeletal specimens with taxonomic value are rare. Using Plio-Pleistocene otoliths from the famous Chochen-Tsailiao locality, we further demonstrated that they are numerous in the sediments, with high abundance and broad distribution. Study small fish remains for attaining a high resolution on the spatiotemporal dynamics of fish faunas through time and for providing the data necessary for conservational purposes is recommended.