Search for: All records

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. 

Abstract New Guinea is the largest tropical island in the world and hosts immense endemic biodiversity. However, our understanding of how the gradual emergence of the terrestrial ecosystems of the island over the last 40 Myr has generated this biological richness is hampered by poorly documented species diversity and distributions. Here, we address both these issues through an integrative taxonomy and biogeographical approach using Hylophorbus, a New Guinea-endemic genus of frogs with 12 recognized species. We delimited candidate species by integrating mitochondrial DNA, nuclear DNA, and bioacoustics, then investigated their evolutionary history. Our results suggest that the current taxonomy of the genus misses true species diversity by ≥3.5-fold. Nevertheless, most candidate species (27) remain unconfirmed because of missing data, whereas five were identified unambiguously as undescribed (we describe three of these formally). Time-calibrated phylogenetic analyses suggest that Hylophorbus diversification began ~9 Mya in the northern or eastern portion of New Guinea. It would appear that lineages dispersed to new terrestrial habitats in the west, notably uplifted by the central range orogeny, until eventually reaching the Bird’s Head during the Mio-Pliocene (7–5 Mya). Conversely, a past barrier appears to have prevented north–south dispersal. These data suggest that new habitat availability has primarily driven the diversification of Hylophorbus. 

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. 

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.  

Roberts et al. (2022) presented a taxonomic decision, in which they proposed the species name longhagen for a single, poorly preserved specimen of elapid New Guinean snake in the species assemblage known as the Toxicocalamus loriae Group. Geographically widespread populations in this species group had long been united under a single name even though some character variation had been noted, and only a thorough morphological study by Kraus et al. (2022), published shortly after the description of T. longhagen, confirmed additional species-level diversity and the detail of character analysis needed to differentiate species in this group. Their work made clear that only examination of many specimens would allow an assessment of interspecific variation and species boundaries, and this had been explained to the authors of the Roberts et al. paper ahead of their manuscript submission. The authors of the Kraus et al. paper had examined the specimen used to diagnose T. longhagen, as well as a series of similar specimens, and found it impossible to make a reliable species-level determination. Our detailed evaluation of the taxon longhagen reveals that it is insufficiently differentiated from the now-known species of the T. loriae Group, that it cannot confidently be assigned to any of these species, and that none of the existing specimens of snakes in this group can be assigned to T. longhagen. It follows that T. longhagen as currently defined is a taxonomic nomen dubium. It will retain this status until such time when additional data or additional material can lead to a resolution of its taxonomy. 

We describe a new species of Lepidodactylus from Umboi Island, just to the west of New Britain. It is a member of the Lepidodactylus guppyi Group and can be distinguished from all other Melanesian Lepidodactylus by aspects of digital scalation, digital webbing, enlarged femoral/precloacal scales, and color pattern. It is genetically distinct from its closest congeners, and genetic and morphological data indicate that the new species is most similar among named species to Lepidodactylus guppyi from the Solomon Islands, but it diverged from this species and other close relatives approximately 8 MYA or longer at a time prior to the existence of the island that it now occupies. The new species is known from only three individuals collected on a single tree, and efforts to find more animals in what seemed good habitat nearby were unsuccessful. This duplicates the pattern of apparent rarity seen for many Lepidodactylus species. Sufficient habitat exists on Umboi Island for arboreal geckos, suggesting that the species is not actually endangered but is ecologically cryptic. However, lack of needed information leads us to assess this species’ conservation status as Data Deficient. 

Melanesian blindsnakes of the genus Gerrhopilus have been little collected or researched. I examined specimens assigned in museums to Gerrhopilus inornatus and found considerable morphological diversity among them that indicates the presence of multiple species. I redescribe G. inornatus (Boulenger) based on the holotype and one additional specimen, and I describe six new species among specimens currently subsumed under that name from Papua New Guinea: Gerrhopilus flavinotatus sp. nov., Gerrhopilus lorealis sp. nov., Gerrhopilus papuanorum sp. nov., Gerrhopilus polyadenus sp. nov., Gerrhopilus slapcinskyi sp. nov., and Gerrhopilus wallachi sp. nov. Each species is currently known from only 1–3 specimens, and all but two are known only from single localities. In addition to traditional information on scale counts, habitus, and color patterns, I found the numbers and distributions of epidermal glands among the head shields to be especially useful for discriminating among species. The number of recognized Melanesian Gerrhopilus has increased tremendously in recent years, but the region has been poorly sampled for these snakes, and it is to be expected that additional species will be identified at such time as surveys can more effectively target these cryptic snakes.