Crocodylian princess in Taiwan: Revising the taxonomic status of Tomistoma taiwanicus from the Pleistocene of Taiwan and its paleobiogeographic implications

<p><em>Toyotamaphimeia</em>&nbsp;is an extinct crocodylian lineage whose name is derived from a mythological Japanese princess. Here, we reexamine the type specimens of a long-forgotten species:&nbsp;<em>Tomistoma taiwanicus&nbsp;</em>from the Pleistocene of Tainan (Taiwan) and revise its taxonomic status to&nbsp;<em>Toyotamaphimeia taiwanicus&nbsp;</em>comb. nov., leading to the first recognized species of&nbsp;<em>Toyotamaphimeia&nbsp;</em>outside Japan. Our phylogenetic analyses also support this taxonomic assignment and, more interestingly, further suggest an East Asian lineage. In addition,&nbsp;<em>Toyotamaphimeia taiwanicus</em>&nbsp;represents a tropical species, resolving a long-lasting puzzle of why&nbsp;<em>Toyotamaphimeia&nbsp;</em>only inhabited the much higher latitudinal area (Japan). Given the large body size of&nbsp;<em>Toyotamaphimeia taiwanicus</em>&nbsp;(about 7 m) and the fact that it is geologically older than&nbsp;<em>Toyotamaphimeia machikanensis</em>&nbsp;from Japan, we propose a novel evolutionary scenario: the genus&nbsp;<em>Toyotamaphimeia&nbsp;</em>originated in Taiwan and evolved to a large body size with gigantothermic physiology, allowed an Out-of-Taiwan scenario, and dispersed further north to Japan. Our taxonomic identification shows the presence of an extinct endemic crocodylian species from the Pleistocene of Taiwan with large-scale paleogeographic implications, and this study, with our recent progress in vertebrate paleontology in Taiwan, should provoke more in-depth paleontological research on the Pleistocene extinction.</p>