Stephen J. Richards

A new species of miniature (males < 13 mm SUL) eleutherognathine asterophryine microhylid frog is described from the mountains of Papua New Guinea. Cophixalus leptoglossa sp. nov. differs from all other New Guinean Asterophryinae in its unique combination of having a distinct cream stripe along the canthus, a dark brown hourglass mark on the dorsum, eight presacral vertebrae, no prepollex element and two prehallux elements, tips of toes 2–5 expanded, Musculus depressor mandibulae located entirely behind posterior margin of tympanum, and omosternum present. In its small size, reduced first finger and strap-like tongue the new species is morphologically most similar to the genus Paedophryne. However previously published genome-scale sequencing using Single Nucleotide Polymorphisms (SNPs) confirms that it is a deeply divergent lineage within the genus Cophixalus. The new species inhabits leaf litter on the forest floor where males call predominantly during the early morning and late afternoon. It is currently known only from the Lake Kutubu Wildlife Management Area and nearby forested ridges at the eastern edge of the Agogo Range in New Guinea’s central cordillera.

We describe a new species of torrential-stream associated pelodryadid treefrog in the genus Amnihyla from high elevations in the Maoke Mountains of western New Guinea. The new species is similar to Amnihyla pratti but can be differentiated by aspects of colouration on the ventral and lateral surfaces, most notably a distinctive cluster of green lateral tubercles beginning near the angle of the jaws. The type series of this new species shows marked female-biased size dimorphism with the largest female estimated to be just over 1.5 times the length and six times the weight of the largest male. This sexual dimorphism seems to be characteristic of a putative clade of Amnihyla centred in the mountains of western and central New Guinea, and which includes the new species, A pratti and two other previously recognised species.

A new species of dragonfly, Anax bismarckensis sp. nov., is described based on a male from New Britain, Bismarck Archipelago, Papua New Guinea. The new species differs from most of its New Guinean congeners by lacking an apico-lateral spike on the cerci and its abdomen being 1.4 times as long as the hind wing. Anax bismarckensis sp. nov. represents the 8th species of the genus known from Papua New Guinea and is currently known only from the holotype from Vudal on New Britain, collected 03.viii.1971. It seems to coexist on New Britain with the very similar long-bodied Anax maclachlani Förster, 1898 (male abdomen >1.3 times length of hind wing) and Anax guttatus (Burmeister, 1839), a short-bodied species (male abdomen <1.3 times length of hind wing). The male of A. bismarckensis sp. nov. is compared with all other congeners from Melanesia. In addition, the range of Anax insulanus, Theischinger, Kalnins & Marinov, 2024, from the Solomon Islands is extended to include Bougainville, situated within the political boundary of Papua New Guinea.

Western Melanesia sits at the junction of three major tectonic plates, characterised by dynamic plate interactions and geological diversity. Tectonic activity in this region has given rise to modern New Guinea, a relatively young island with extreme topographic heterogeneity and evolutionarily complex biota. New Guinea—particularly the East Papuan Composite Terrane (EPCT)—supports exceptional frog diversity; however, evolutionary histories of many frogs of the EPCT are poorly understood. The microhylid frog genus Mantophryne currently includes five described species ( M. axanthogaster , M. insignis , M. louisiadensis , M. menziesi and M. lateralis ), with the first four confined to small portions of the EPCT and the last distributed across the eastern half of New Guinea. The biogeographic history of these frogs remained incompletely resolved at the time of our study. We estimate that Mantophryne diverged from other microhylid genera approximately 14.4 million years ago (MYA) and began to speciate ca. 8.5 MYA. We recover eight distinct lineages within frogs assigned to M. lateralis , which started to diverge ca. 5.5 MYA. Dispersal of Mantophryne out of the EPCT occurred in the late Pliocene, around the time the Central Highlands expanded eastward to connect with the EPCT. Six pairs of sister lineages arose during a time of significant climate reorganisation in the Late Pliocene—Early Pleistocene when it is possible that areas to the north of the Central Highlands experienced increased precipitation, while areas south of the Central Highlands experienced lower rainfall, resulting in contraction of rainforests and expansion of savannahs. We did not identify any significant differences in habitus between lineages, other than M. louisiadensis which is much larger than all other Mantophryne, and has exceptionally high sexual‐size dimorphism. While an interrogation of the putative cryptic species complex within the M. lateralis clade is beyond the scope of our study, we find that a combination of tectonic rearrangement and climatic history are likely responsible for most of the diversity within the genus that we see today.

The Solomon Islands Archipelago comprises a complex array of islands that have never been connected by land with any other region, nonetheless they have a diverse and endemic biota. Here we describe a new species of gecko in the genus Gehyra that appears to be endemic to eastern portions of the paleo-island of Greater Bukida – the contemporary islands of Choiseul, Santa Isabel and Nggela Sule. Gehyra mccoyi sp. nov. was formerly confused with Gehyra oceanica, a species complex that occurs widely across the tropical Pacific including the Solomon Islands but can be distinguished by several aspects of scalation and by having a more depressed habitus. Gehyra mccoyi sp. nov. is the first species of Gehyra recognised that is endemic to the Solomon Islands, partially filling a gap between island systems to the east (Vanautu and Fiji) and west (Admiralty Islands) that are known to support endemic species in this genus.

The New Guinea Big-eared Bat Pharotis imogene is one of the region’s least known mammals, with prior confirmed records from only two localities, both in Central Province, Papua New Guinea. We report the recent capture of a Pharotis imogene from Kuriva Forestry Station, approximately 50 km north of Port Moresby, extending the species’ known range more than 130 km northwest of its previous limit. We describe and illustrate the new specimen and its habitat and provide the first description of this species’ echolocation call.

We describe a new species of pelodryadid treefrog from a montane stream traversing karst terrain in the Star Mountains of western Papua New Guinea. Litoria stellarum sp. nov. is morphologically similar to L. becki (Loveridge, 1945), a species that is widespread in montane grassland habitats in central Papua New Guinea, but can be distinguished by its more angular snout and the presence of vocal slits in adult males (absent in L. becki). Based on its morphology and ecology we are confident the new species belongs to a monophyletic clade of torrent-breeding Litoria that reaches its greatest diversity in the rugged mountains of New Guinea’s Central Cordillera. Litoria stellarum sp. nov. is the second species in the radiation of torrent-breeding Litoria to be described from high-elevation karst habitats in Papua New Guinea, however in the absence of better ecological data it is not clear whether these species can be considered karst specialists. The single known locality for the species is in a restricted high elevation habitat suggesting it might be vulnerable to climate change. However, we suggest it should be considered Data Deficient until such time as its distribution and ecology can be better assessed.

Over the last two decades herpetofauna surveys in the South-fold mountains of central New Guinea have revealed many new and locally endemic species. Here, we describe a new species of skink in the genus Prasinohaema from three montane localities in Papua New Guinea’s central ranges spanning approximately 80 km between the Muller Range in the northwest and the Tari Gap in the southeast. Genetic evidence indicates that Prasinohaema scurrula sp. nov. is most closely related to two other predominantly montane species of Prasinohaema, including the type species for the genus P. flavipes. It can be readily distinguished from other Prasinohaema by aspects of body size and proportions, scalation of head and digits, and colouration. The new species is likely arboreal as the paratype was collected in a tree canopy. This could explain the scarcity of observations in a relatively well-sampled region. Despite the small number of known localities there appears to be extensive suitable habitat for this species in the region and there are no major current threats, so we suggest an IUCN status of Least Concern. To facilitate further taxonomic work on Australasian skinks we also provide preferred definitions and names for key scalation states which have been variably defined and/or assigned different names in previous literature.

We describe two new species of asterophryine microhylid frogs from the Gulf Province lowlands of south-central Papua New Guinea. Cophixalus flavopunctatus sp. nov. is a small member of the genus (SUL 13.5–15.5 mm) that is most commonly encountered on stream banks. It can be distinguished from all congeners by its small size and the presence of yellow tubercles on the dorsum. Calling activity appears to peak in the early morning and evening when males produce a train of melodious peeping notes from within litter on the forest floor. Oreophryne purari sp. nov. is a medium-sized member of the genus (SUL 24.0 mm in the only male) that calls at night from high in the forest canopy with a series of harsh honking notes. Its morphology and call structure closely resemble O. loriae (Boulenger, 1898), a species known from eastern Papua New Guinea, but it differs from that species by having a cartilaginous connection between the procoracoid and the scapula (vs. a ligamentous connection), and by several aspects of morphometrics and colouration. The discovery and description of these two species adds to an already impressive known frog diversity in the lowland forests of southern Papua New Guinea.

We describe a new species of gecko in the Lepidodactylus novaeguineae group from Misima Island, Milne Bay Province, Papua New Guinea. Lepidodactylus exoris sp. nov. can be distinguished from congeners by aspects of body size, toe shape, scalation and colouration. This discovery provides the first confirmed instance of L. novaeguineae group and L. orientalis group species on the same island, and further emphasises high herpetofaunal endemism in the recently delimited Milne Bay Province Biodiversity Hotspot of far eastern Papua New Guinea.