A new species of the genus <i>Ocadia</i> (Testudines: Geoemydidae) from the middle Miocene of Tanegashima Island, southwestern Japan and its paleogeographic implications

Abstract

A new geoemydid turtle, Ocadia tanegashimensis (Testudines: Geoemydidae) is described on the basis of a relatively well-preserved shell from the lower middle Miocene of Tanegashima Island, Kagoshima Prefecture, southwestern Japan. This species is clearly distinguished from two congeneric species (extant O. sinensis and O. nipponica from the middle Pleistocene of eastern Japan) due to the presence of the following character states: length of the entoplastron as long as the interhyoplastral suture, the costals dovetailed with one another in outline, the third pleural overlapping only the sixth and seventh peripherals. The present study suggests that the initial intrageneric diversification of Ocadia began not later than the early Miocene in eastern Asia.

The chelonians from the Latest Miocene–Earliest Pliocene localities of Allatini and Pylea (East Thessaloniki, Macedonia, Greece)

“…The main differences are found on the carapace, which is not preserved in the Allatini specimen. The only character that is preserved in our specimen is the length of the entoplastron relative to the interhyoplastral suture (character 8 in Takahashi et al, 2013). The length of the entoplastron in the Allatini specimen is shorter than the interhyoplastral length, similar to M. japonica but contrasting the condition in M. mutica and M. yabei.…”

“…The length ratio between these elements cannot be determined precisely, but appears to fall within the range expected for Mauremys. Regarding the Asian Mauremys, Takahashi et al (2013) list a number of differences among hingeless geoemydids from Asia and Europe with an entoplastron crossed by the humero-pectoral sulcus. The main differences are found on the carapace, which is not preserved in the Allatini specimen.…”

Morphological characterization and phylogenetic relationships of Indochinese box turtles—The Cuora galbinifrons complex

“…Inconsistencies between taxonomy and phylogenetic patterns have been revealed to be common among closely related species due to divergent markers, hybridization and introgression of wild populations, arbitrary sections of clines, artificial subdivisions of species or a random combination of these factors (Naksri, Tong, Lauprasert, Suteethorn, & Claude, 2013;Petit & Excoffier, 2009;Zhang, Nie, Huang, Pu, & Zhang, 2009;Zink & Barrowclough, 2008). Defining the interspecific relationships and species boundaries for Cuora has been a challenging endeavor for the systematic and conservation communities.…”

“…According to reports, 51.9% of existing turtle species are recognized as threatened, 20% as critically endangered, and 35.3% are critically endangered or endangered by the World Conservation Union (IUCN TFTSG, 2018). The genus Cuora , a member of the Geoemydidae family, are restricted to southeast and east Asia (Takahashi, Ishido, & Hirayama, ). Among them in the genus Cuora , 12 species are critically endangered and one species is endangered on the IUCN Red List of Threatened Species (IUCN TFTSG, 2018).…”

“…Naksri et al, 2013). Therefore, it is reasonable to maintain picturata as a full species and assume galbinifrons and bourreti as subspeciesof C. galbinifrons due to their coherent distribution area with no real boundaries.…”