Geckos are one of the most widespread and diverse squamate taxa in the Pacific region and play a major role in explaining colonisation history and locating faunal affinities. We describe a new species of large growing Gehyra Gray, 1834 from the Loyalty Islands and Vanuatu based on molecular phylogenetics and morphology. Gehyra georgpotthasti n. sp. was formerly included within G. vorax Girard, 1857, but has longer postmental scales, more postrostral scales, and usually fewer subdigital lamellae and precloacal-femoral pores. We here designate a lectotype for G. vorax and propose a close relationship of this species to G. georgpotthasti n. sp. and G. membranacruralis King & Horner, 1989. The phylogenetic position of G. marginata Boulenger, 1887 as sister species to G. oceanica (Lesson, 1830) is described and new morphological evidence also disproves the previously supposed close relationship with G. vorax. Both G. georgpotthasti n. sp. and G. vorax have been introduced to Polynesia by human activities, as Polynesian populations of both taxa are genetically and morphologically indistinguishable from populations within their respective native ranges. But even within its native range, G. georgpotthasti n. sp. shows little genetic variability, inferring a recent colonisation history. Systematics of this group confirm the close zoogeographic relationship between Vanuatu and the Loyalty Islands.
