A Kuroiwa’s leopard gecko subspecies described post-extinction

A member of the Goniurisaurus kuroiwae Group
Kuroiwa’s Leopard Gecko, Goniurosaurus kuroiwae is a eublepharid gecko endemic to the central part of the Ryukyu Archipelago of Japan, in the subtropical northwestern Pacific. It is isolated from the rest of its congeners occurring in southeastern continental China, northern Vietnam, and adjacent coastal islands, and the species represents the easternmost Old World member of the family. Because this species (or species complex) consists of a number of allopatric and apparently diagnosable divergent insular populations, and its classification has been controversal.
In the latest revision, its populations were combined into a single species comprising five extant subspecies: G. k. kuroiwae; G. k. orientalis; G. k. splendens; G. k. toyamai; and G. k. yamashinae. Grismer et al. (1999, 2002), adopted the evolutionary species concept, referred to each of these taxa as full species, and this taxonomic treatment has been widely accepted in the context of the recent trend of disuse of the subspecies rank by herpetologists.
However, Nakamura et al. (2014) believe that such changes in taxonomic rank are premature, because diagnostic characters originally proposed to define each of these taxa are few in number and, moreover, include those with highly variable character states. For example, yellow-brown to gold iris color was considered as one of the character states that discriminates G. k. yamashinae from the other subspecies whose irises are blood-red in color, but G. k. kuroiwae populations from Okinawajima and adjacent islets also include individuals with more or less yellow irises. They therefore prefer to take a conservative stance with respect to the taxonomic treatment of G. kuroiwae sensu lato by maintaining the framework of Grismer et al. (1994).
In a new paper Nakamura and colleagues (2014) describe a new subspecies of the Kuroiwa’s Leopard Gecko, Goniurosaurus kuroiwae yunnu, based upon remains from a midden after the population has apparently become extinct. The new taxon differs from the other conspecific subspecies in having a unique combination of osteological character states: in particular, the maxilla contains a posteriorly extended maxillary shelf and a scarcely inclined lateral wall above the posterior tooth row, and the frontal contains a widened anterior section and a laterally overhanging anterior part of lateral prefrontal facet, both of which differentiate this new subspecies from the morphologically most similar G. k. kuroiwae. The new subspecies, endemic to Yoronjima Island, may have gone extinct, together with several other amphibians and reptiles on the island. The extinction was most likely due to human-related deforestation and increased predation pressure from introduced weasels.
Grismer, L.L., Ota, H., Tanaka, S. (1994): Phylogeny, classification, and biogeography of Goniurosaurus kuroiwae (Squamata: Eublepharidae) from the Ryukyu Archipelago, Japan, with description of a new subspecies. Zool. Sci. 11: 319-335.

Grismer, L.L., Viets, B.E., Boyle, L.J. (1999): Two new continental species of Goniurosaurus (Squamata: Eublepharidae) with a phylogeny and evolutionary classification of the genus. J. Herpetol. 33: 382-393.

Grismer, L.L., Shi, H., Orlov, N.L., Ananjeva, N.B. (2002): A new species of Goniurosaurus (Squamata: Eublepharidae) from Hainan Island, China. J. Herpetol. 36: 217-224.

Nakamura, Y., Takahashi, A., & Ota, H. (2013). Recent cryptic extinction of squamate reptiles on Yoronjima Island of the Ryukyu Archipelago, Japan, inferred from garbage dump remains. Acta Herpetologica, 8(1), 19-34.

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