Biogeographic and Phylogenetic Relationships of Some Scincella (SQUAMATA: SCINCIDAE) from CHINA and North AMERICA Inferred from 12S rRNA Gene Sequence

Grayian distribution denotes the biological similarities between southeastern North America and East Asia. Using 12S rRNA gene sequences of mitochondrial DNA, we present evidence that the North American ground skinks in Scincella (Squamata: Scincidae), Sc. lateralis and relatives, exhibit classic Grayian distribution, emerging genetically from within the Chinese group of Scincella that includes Sc. modesta and Sc. tsinlingensis; all derivatives from Chinese Sc. reevesii. A superficially similar undescribed species , as yet known only from Dinghushan, Guangdong Province, China, also arises within this group but lacks the lower eyelid “spectacle” usually thought diagnostic of the genus Scincella. Our molecular analyses confirm previous work indicating that Asian Sphenomorphus is paraphyletic with respect to Scincella, confirm that the American Scincella include “Sphenomorphus” cherriei, necessitating that the spectacle scale has been independently either developed or lost in separate lineages of Scincidae, and provide further evidence for the separation of Kaestlea travancorica from Scincella. The separation time of North American Scincella from their Chinese congeners dates from the Miocene in Tertiary about 7.3-21.6 million years ago when Beringia was extant and mesic. Our studies contribute further to phylogenetics and biogeography of Scincella from North America and China and call for further international collaboration on resolution of taxonomic problems among lygosomine species.