Lepidodactylus

Abstract: I describe five new species of Lepidodactylus from New Guinea or adjacent islands that are members of Brown Parker's (1977) phenetic Groups I and II and belong to the clades identified as the L. orientalis, L. pumilus, and L. novaeguineae groups of Oliver et al. (2018a). One of the new species is restricted to an isolated mountain range on New Guinea; the remainder inhabit offshore islands ranging from 3-250 km from New Guinea. These species are distinguished from their congeners primarily by unique combinations of toe lamellar numbers and shape, numbers and distribution of enlarged precloacal/femoral scales and pores, toe webbing, toe width, and color pattern. These clades are ancient, and the ancestor of one of them has been on the East Papuan Composite Terrane for at least 28 MY, highlighting the long-term importance of that former large island in generating regional biodiversity. At least one, and probably three, of the new species are inhabitants of forest interiors; one occupies disturbed coastal areas; and the habitat of the last is currently unsurmisable. All of the new species likely have restricted geographic distributions, with four of them being limited to one or a few small islands. As a result of their small ranges, rapid habitat conversion in the ranges of some of these species, and the threat of further habitat loss in the others, most of these species are of conservation concern although it is uncertain if any of them is under immediate threat.

Abstract: Lepidodactylus lugubris, often cited as an exception to the rule that vertebrate parthenogenetic species must arise via hybridization of two sexual species, is shown to be of hybrid origin. Using karyotypes, sequences of the cytochrome-b gene, and protein electrophoresis we have shown that the maternal ancestor is the recently rediscovered species L. moestus from Micronesia; the paternal ancestor is an undescribed species whose range extends from French Polynesia to the Marshall Islands. Lack of sequence divergence between some individuals of L. lugubris and L. moestus suggests that independent clone production through hybridization of the sexual ancestors is probably recent, ongoing and has occurred several times. The only known location where both parental species and L. lugubris are sympatric is Arno Atoll (Marshall Islands). Field and museum surveys of over 10000 individual geckos establish that previously reported sexual populations of L. lugubris are misidentified and in fact are either the sexual parental species, other undescribed sexual species, or rare developmentally abnormal males.

Abstract: We describe a new species of Lepidodactylus with an unusual distribution across scattered localities in three isolated mountain ranges of northeastern New Guinea. It is a member of the Lepidodactylus pumilus group and can be distinguished from all other Melanesian Lepidodactylus by aspects of size, scalation, digital webbing, and coloration. Previously published genetic and morphological data indicate that the new species is most similar to Lepidodactylus magnus, but it diverged from this species and other close relatives in the mid-Miocene or earlier, potentially on islands of the former South Caroline Arc. Estimated divergence dates between the new species and its sister taxon suggest that cladogenesis occurred before the uplift of the mountains that they currently inhabit. Recent systematic work also emphasizes an apparent pattern of increasing body size with elevation in species from the Lepidodactylus pumilus group from northeastern New Guinea, with the largest species occurring in montane habitats where few or no other gecko species are known. Both lines of evidence are consistent with an existing hypothesis that the Lepidodactylus pumilus group is an old insular lineage within which contemporary species diversity and distributions have been strongly shaped by low ability to effectively compete against other aggressive geckos in species-rich lowland rainforests. The role that biotic interactions may have played in shaping tropical gecko communities along elevational gradients warrants further investigation.

Abstract: Heinicke, M. P., Greenbaum, E., Jackman, T. R. & Bauer, A. M. Phylogeny of a trans-Wallacean radiation (Squamata, Gekkonidae, Gehyra) supports a single early colonization of Australia. —Zoologica Scripta, 40, 584–602. The genus Gehyra (34 species) is rare among squamate reptile radiations in spanning continents, extending from southeast Asia to Australia and Polynesia. Among the family Gekkonidae sensu stricto, Gehyra is the only genus that is species rich in Australia. We performed molecular phylogenetic, divergence timing, and ancestral area analyses to investigate the evolutionary and biogeographic history of Gehyra. Phylogenetic analyses resolve Hemiphyllodactylus as the closest relative of Gehyra. Some data also link Perochirus to this group, but previously suggested relationships with other morphologically similar genera of geckos are not supported. Within Gehyra, three geographically discrete clades are recovered, respectively, concentrated in Asia, the Pacific islands and Australia. Ancestral area analyses suggest that Gehyra originated in Asia, with a single colonization of Australia occurring in the mid-Cenozoic. This date places the time of Gehyra colonization prior to those of other Australian gekkonid geckos, but after the near-endemic pygopodoid geckos, a Gondwanan relictual group. Based on these dates, times of origin may best explain relative differences in species diversity among Australian gekkotans. In contrast, although originating earlier, Gehyra is less diverse in Asia than in Australia. This pattern may be explained by the long-term presence of many competing, ecologically similar genera in Asia (e.g. Gekko, Hemidactylus, Lepidodactylus), whereas nearly all pygopodoids in Australia (the only gekkotans present at the time of colonization of Australia by Gehyra) are ecologically distinct.