Historical Biogeography of the Terrestrial Reptiles of Japan: A Comparative Analysis of Geographic Ranges and Molecular Phylogenies

Origin and intraspecific diversification of the scincid lizard Ateuchosaurus pellopleurus with implications for historical island biogeography of the Central Ryukyus of Japan

“…The present geographic distribution of this species largely ranges along both sides of the Tokara Gap, which is superficially different from the general biogeographic pattern of terrestrial reptiles in the Ryukyu Archipelago (e.g., Ota 1998;Okamoto 2017). However, the present results indicated that the range of this species was limited to Okinawa, Amami, and southern Tokara Groups before recent dispersal.…”

“…Okamoto (2017) discussed that most Central Ryukyu endemics can be categorized as young, having been isolated in the late Miocene, and the old relicts that were isolated in the Eocene. The latter includes two genera with relictual geographic ranges, Geoemyda Gray, 1834 and Goniurosaurus Barbour, 1908, which As noted by Okamoto (2017), the geographic ranges of sister taxa of younger endemics varied across taxa, such as Ovophis okinavensis (Boulenger, 1892), which has sister species limited to Taiwan, and Takydromus smaragdinus (Boulenger, 1887), which has two or more equally diverged congeners in surrounding areas, including the Japanese main islands, the Sakishima Group, Taiwan, and the continent. Then, Okamoto (2017) found that the Central Ryukyus were simultaneously isolated from surrounding areas, although he did not mention any specific geological events.…”

“…Previous biogeographic reviews of terrestrial reptiles and amphibians that inhabit the archipelago (Hikida & Ota 1997;Ota 1998, Ota 2000 revealed strong endemicity in the central part of the archipelago, which consists of the southern part of the Tokara Group ("southern Tokara" hereafter; sites 8 and 9 in Fig. 1) to the Okinawa Group ("the Central Ryukyus" hereafter; see Kaito & Toda 2016;Okamoto 2017); alternatively, the Osumi Group (sites 1-3 and adjacent islands in Fig. 1) and the northern part of the Tokara Group ("northern Tokara" hereafter; sites 4-7 in Fig.…”

“…Based on prior molecular phylogenetic studies on Ryukyu terrestrial reptiles (e.g., Toda et al 1999;Ota et al 2002;Lue & Lin 2008), a recent review of Japanese terrestrial reptile historical biogeography (Okamoto 2017) mentioned that most of the Central Ryukyu endemics had their closest relatives in surrounding areas (i.e., the Japanese main islands, the Sakishima Group, Taiwan, and/or the Asian continent), with divergence times around the late Miocene. The review also suggested that some endemics were relicts with exceptionally older origins around the Eocene, whereas others might have colonized the area by overseas dispersal, with younger origins in the Pliocene (Okamoto 2017).…”

Widespread misperception about a major East Asian biogeographic boundary exposed through bibliographic survey and biogeographic meta‐analysis

“…Even though the fine-scale faunal biogeography in the Tokara archipelago is not well analysed, studies of various taxa have emphasised the significant effect of the Tokara gap on the faunal pattern (Chen et al, 2015;Ichikawa et al, 2014;Yamasaki et al, 2015), with a few exceptions suggesting overseas dispersals across the boundary (Kurita & Hikida, 2014b;Yamazaki et al, 2017). Especially for reptiles, the distribution information is well organised and there are several systematic reviews (Okada, 1927;Okamoto, 2017;Ota, 1998). The major idea is to divide the Tokara archipelago into north and south by the Watase line.…”