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Papuan snakes of the genus Aspidomorphus have long been taxonomically problematic, but nomenclature within this group has been stable at three recognized species since 1967. Previous genetic work suggested the presence of a number of cryptic but currently unrecognized candidate species in the genus. In 2004, I obtained a series of Aspidomorphus from Sudest Island, Milne Bay Province, Papua New Guinea that were clearly different from currently recognized species, and I describe that species here as A. dimorphus sp. nov. This species exhibits a striking bimodality in color pattern in adults, here termed the “orange morph” and “dark morph”. This dimorphism is not related to sex, and both forms have earlier been shown to be genetically identical. Description of A. dimorphus sp. nov. begins the process of bringing taxonomic clarity to a genus long held in the grip of nomenclatural stasis. It furthermore highlights again the importance of Sudest Island for biodiversity endemism.  

Australo-Papuan snakes of the genus Dendrelaphis have historically been a taxonomically confusing group, with 28 nomina applied to snakes in this region. Recent taxonomic revision has established the presence of nine valid species in this area, though few specimens were examined from across most of the large island of New Guinea. This lacuna, along with unreliable application of names to Melanesian Dendrelaphis in museum collections, means that the ranges of each species remain to be properly resolved on New Guinea and islands immediately to the east. Herein I examine the taxonomic status of Dendrelaphis specimens from outlying large islands in Milne Bay Province, off the southeastern tip of New Guinea, and I find that each of the three large islands of the Louisiade Archipelago, as well as Woodlark Island, contain their own endemic species. Based on hemipenial morphology, three of these species (D. anthracina sp. nov., D. melanarkys sp. nov., D. roseni sp. nov.) belong to the D. papuensis group and the last (D. atra sp. nov.) to the D. punctulatus group. Identification of the first three species requires reassessment and rediagnosis of D. papuensis. Two of the new species are characterized by ontogenetic melanization of animals, and a third is also uniformly black with a white chin when adult, though juveniles are unavailable to determine whether melanization also occurs ontogenetically in that species. Melanesian species of Dendrelaphis are largely diagnosed by unique color-pattern features, and this work identifies additional diagnostic features of color pattern for these species and confirms the critical importance of hemipenial differences in distinguishing among similar-appearing species in this region.  

I describe a new species of blindsnake of the genus Ramphotyphlops Fitzinger, 1843, from Woodlark Island, off the southeastern tip of New Guinea. The new species is a member of the R. flaviventer (Peters, 1864) group and is characterized by a unique combination of number of longitudinal scale rows, details of the shape of the rostral scale, color pattern, and shape of the tail spine. The nearest related species (R. depressus Peters, 1880) in this group occurs 380 km to the northeast from the new species, and the remaining species of the group lie no closer than 2570 km distant. The new species seems most similar morphologically to relatives from far western New Guinea, but this could be due to homoplasy or plesiomorphy. The species seems common in the widespread mature secondary forest that occurs across the island, but non-traditional land tenure and repeated outside proposals to deforest much of the island pose a continuing series of threats to this and other endemic species on Woodlark. 

I describe four new species of Gehyra from New Guinea and immediately adjacent islands. Two of these are giant species that have long been misassigned to either G. vorax or G. membranacruralis; the other two were previously referred to G. oceanica. Each of the new species has a very circumscribed geographic distribution, with one being known from only a single island, a second from a small portion of southeastern New Guinea and immediately adjacent islands, a third from a small archipelago, and the fourth from foothill forest along the northern versant of eastern New Guinea. Three of these species are found only in the Milne Bay Region of southeastern Papua New Guinea, a region previously identified as having a globally high density of narrow-range endemic reptile and amphibian species. These species provide further extension of that pattern by increasing the number of known endemic herpetofaunal species from that small region to 165. Variation in subcaudal shape is taxonomically useful in Gehyra, but its character-state coding must rely on original tails because aberrant development of subcaudals in some regenerated tails could lead to mischaracterization of this feature.  

Abstract New Guinea and surrounding islands are home to some of the richest assemblages of insular biodiversity in the world. The key geological drivers of species richness in this region are largely considered to be mountain uplift and development of offshore archipelagos—some of which have accreted onto New Guinea—with the role of mountain uplift and elevational gradients receiving more attention than the role of isolation on islands. Here, we examine the distribution of lineage richness and body-size diversity in a radiation of Melanesian lizards that is almost entirely absent from montane habitats but closely associated with islands—the geckos of the genusNactus. Our data indicate that eastern New Guinea—centred on the East Papuan Composite Terrane (EPCT)—shows particularly high levels of endemism and body-size diversity and is also inferred to be a source area for multiple independent colonisations elsewhere in New Guinea, the Pacific and Australia. TwoNactuslineages in Australia have closest relatives occurring to the north of New Guinea’s Central Cordillera, suggesting dispersal through this area in the mid-Miocene, possibly via seaways that would have isolated the islands to the east and west of the proto-Papuan region. Syntopic species tend to differ in body length; however, at a phylogenetic scale, this trait appears to be conservative, with small-sized and large-sized species clustered into separate lineages. These data suggest that species richness in MelanesianNactusis in part explained by morphological diversification enabling the presence of sympatric communities to exist, but to a greater extent by multiple instances of dispersal and extensive allopatric and parapatric speciation, especially in and around the islands of the EPCT. 

Several species of geckos of the genus Lepidodactylus are endemic to the Solomon Islands and very poorly known. I redescribe one of these, L. flaviocularis, from Guadalcanal, based on examination of a second, newly obtained specimen and quantification of diagnostically useful features of the digits. I also describe a closely related new species from nearby Makira Island in the southern Solomon Islands. Both species are distinguished by their large number of undivided subdigital lamellae, extensive toe webbing, and a continuous row of enlarged precloacal/femoral scales. The new species is distinguished from L. flaviocularis by a number of scalational features and the color of the circumorbial scales. Both species are inhabitants of interior forest, and it remains uncertain whether they are naturally rare, rare due to interactions with invasive species, or simply have cryptic ecological habits, though the last seems most likely. Current evidence for both species is consistent with the taxon-cycle hypothesis, which posits ecological displacement to inland habitats of ancient island inhabitants by newer colonizers, but this remains to be critically tested. The limited pool of specimens available for both species necessitates assessing the IUCN conservation status of each as Data Deficient.  

Abstract Sunda-Papuan keelback snakes (Serpentes: Natricidae: Tropidonophis Jan 1863) include 20 species distributed from the Philippines south-east through the Moluccas to New Guinea and Australia. Diversity of this insular snake lineage peaks on the island of New Guinea. Previous phylogenetic studies incorporating Tropidonophis have been limited to multi-locus Sanger-sequenced datasets with broad squamate or family-level focus. We used a targeted-sequence capture approach to sequence thousands of nuclear ultraconserved elements (UCEs) to construct the most comprehensive sequence-based phylogenetic hypothesis for this genus and estimate ancestral biogeography. Phylogenies indicate the genus is monophyletic given recent taxonomic reassignment of Rhabdophis spilogaster to Tropidonophis. All UCE phylogenies recovered a monophyletic Tropidonophis with reciprocally monophyletic Philippine and New Guinean clades. Divergence dating and ancestral range estimation suggest dispersal to New Guinea from the Philippines to have occurred during the Mid-Miocene via the Oceanic Arc Terranes. From Late Miocene into the Pliocene the genus experienced rapid diversification from orogeny of the New Guinean Central Cordillera from Oceanic Arc Terrane accretion on the northern boundary of the Sahul Shelf. Future collecting of missing taxa from the Moluccas and Indonesian Papua will better the understanding of non-volant faunal biogeography and diversification in this tectonically complex Pacific arena.