Luke J. Welton

A spectacular new Philippine monitor lizard reveals a hidden biogeographic boundary and a novel flagship species for conservation.

As humans continue to explore the last uncharted regions of the planet, discoveries of previously unknown species of large vertebrates have become infrequent. Here, we report on the discovery of a spectacular new species of giant, secretive, frugivorous, forest monitor lizard (Genus: Varanus) from the forests of the northern Philippines. Using data from morphology and mitochondrial and nuclear DNA sequences, we demonstrate the taxonomic distinctiveness of this new 2 m long species and provide insight into its historical biogeography and systematic affinities. Our molecular phylogenetic analyses indicate that the new species is closely related to Varanus olivaceus (from southern Luzon and nearby islands), but it differs from this and other varanids with respect to characteristics of scalation, colour pattern, body size, anatomy of the reproductive organs and genetic divergence. The new species appears to be restricted to forests of the central and northern Sierra Madre mountain range; it is separated from the range of V. olivaceus by a more than 150 km stretch that includes at least three low-elevation river valley barriers to dispersal. This discovery identifies a seldom-perceived biogeographic boundary and emphasizes the need for continued biodiversity research in the megadiverse conservation hotspot of the Philippines. It is anticipated that the new species will serve as an important flagship species for conservation efforts aimed at preserving the remaining forests of northern Luzon.

Philippine Bent-Toed Geckos of the Cyrtodactylus agusanensis Complex: Multilocus Phylogeny, Morphological Diversity, and Descriptions of Three New Species

Abstract We review the taxonomic status of Philippine bent-toed geckos previously referred to Cyrtodactylus agusanensis. We delineate four evolutionary lineages within the C. agusanensis complex from the southeastern islands of the archipelago and describe three of these lineages as new species. The new species and true C. agusanensis are identified by numerous, nonoverlapping morphological characters and by allopatric ranges on separate islands. Our morphology-based taxonomic conclusions are bolstered by biogeographic evidence and marked interspecific divergence between monophyletic groups defined by mitochondrial and nuclear DNA sequences. To compliment these descriptions and enable future taxonomic work on Philippine Cyrtodactylus, we rediagnose and redescribe C. agusanensis. Because the holotype of C. agusanensis was destroyed in World War II, we designate a neotype for this species and restrict its geographic range to north central Mindanao Island. Our phylogenetic estimate suggests that the C. agusanensis complex originated in Mindanao and spread progressively north, diversifying incrementally with colonization of successive islands in a south-to-north pattern of biogeographic expansion and allopatric speciation.

Multilocus phylogeny and Bayesian estimates of species boundaries reveal hidden evolutionary relationships and cryptic diversity in Southeast Asian monitor lizards

Recent conceptual, technological and methodological advances in phylogenetics have enabled increasingly robust statistical species delimitation in studies of biodiversity. As the variety of evidence purporting species diversity has increased, so too have the kinds of tools and inferential power of methods for delimiting species. Here, we showcase an organismal system for a data‐rich, comparative molecular approach to evaluating strategies of species delimitation among monitor lizards of the genus Varanus. The water monitors (Varanus salvator Complex), a widespread group distributed throughout Southeast Asia and southern India, have been the subject of numerous taxonomic treatments, which have drawn recent attention due to the possibility of undocumented species diversity. To date, studies of this group have relied on purportedly diagnostic morphological characters, with no attention given to the genetic underpinnings of species diversity. Using a 5‐gene data set, we estimated phylogeny and used multilocus genetic networks, analysis of population structure and a Bayesian coalescent approach to infer species boundaries. Our results contradict previous systematic hypotheses, reveal surprising relationships between island and mainland lineages and uncover novel, cryptic evolutionary lineages (i.e. new putative species). Our study contributes to a growing body of literature suggesting that, used in concert with other sources of data (e.g. morphology, ecology, biogeography), multilocus genetic data can be highly informative to systematists and biodiversity specialists when attempting to estimate species diversity and identify conservation priorities. We recommend holding in abeyance taxonomic decisions until multiple, converging lines of evidence are available to best inform taxonomists, evolutionary biologists and conservationists.

A NEW BENT-TOED GECKO (GENUS CYRTODACTYLUS) FROM SOUTHERN PALAWAN ISLAND, PHILIPPINES AND CLARIFICATION OF THE TAXONOMIC STATUS OF C. ANNULATUS

Abstract We describe a new species of gekkonid lizard from Palawan Island, southwestern Philippines. The new species differs from all Philippine Cyrtodactylus and all other phenotypically similar Southeast Asian Cyrtodactylus by characteristics of external morphology, color pattern, and body size. The new species is common in low- to mid-elevation primary growth forest and disturbed lowland riparian gallery forests along the southeast coastal foothills of Mt. Mantalingajan, on southern Palawan Island. To complement the description of the new species and enable future taxonomic work, we redescribe Cyrtodactylus annulatus, revise its diagnosis, and delineate its geographic range. To clarify the taxonomic status of this species with respect to other Philippine taxa and because the holotype of C. annulatus was destroyed in WWII, we designate a neotype for this species.

The amphibians and reptiles of Luzon Island, Philippines, VIII: the herpetofauna of Cagayan and Isabela Provinces, northern Sierra Madre Mountain Range

Abstract We provide the first report on the herpetological biodiversity (amphibians and reptiles) of the northern Sierra Madre Mountain Range (Cagayan and Isabela provinces), northeast Luzon Island, Philippines. New data from extensive previously unpublished surveys in the Municipalities of Gonzaga, Gattaran, Lasam, Santa Ana, and Baggao (Cagayan Province), as well as fieldwork in the Municipalities of Cabagan, San Mariano, and Palanan (Isabela Province), combined with all available historical museum records, suggest this region is quite diverse. Our new data indicate that at least 101 species are present (29 amphibians, 30 lizards, 35 snakes, two freshwater turtles, three marine turtles, and two crocodilians) and now represented with well-documented records and/or voucher specimens, confirmed in institutional biodiversity repositories. A high percentage of Philippine endemic species constitute the local fauna (approximately 70%). The results of this and other recent studies signify that the herpetological diversity of the northern Philippines is far more diverse than previously imagined. Thirty-eight percent of our recorded species are associated with unresolved taxonomic issues (suspected new species or species complexes in need of taxonomic partitioning). This suggests that despite past and present efforts to comprehensively characterize the fauna, the herpetological biodiversity of the northern Philippines is still substantially underestimated and warranting of further study.

Amphibians and Reptiles, Luzon Island, Aurora Province and Aurora Memorial National Park, northern Philippines: new island distribution records

We report 35 new amphibian and reptile distribution records for two regions within the southern Sierra Madre Mountain Range, Aurora Province, central Luzon Island, Philippines. Together with results of our previous survey work in Aurora, our new data result in a total of 82 amphibian and reptile species for the area. These results highlight the degree to which the island’s biodiversity continues to be underestimated and poorly understood. We report on observations of rarely encountered species including the skink Sphenomorphus leucospilos , the forest gecko Luperosaurus cf. cumingii , and a sensational new species of monitor lizard, V aranus bitatawa . Our recent collections clarify the conservation status of the “critically endangered” Polillo Island forest frog Platymantis polillensis , now known to be widespread, abundant, and common throughout Camarines Norte, Quezon, and Aurora Provinces on the adjacent mainland of Luzon Island. These results add to our growing understanding of many species’ distributions in the region.

The Eurasian invasion: phylogenomic data reveal multiple Southeast Asian origins for Indian Dragon Lizards

BackgroundThe Indian Tectonic Plate split from Gondwanaland approximately 120 MYA and set the Indian subcontinent on a ~ 100 million year collision course with Eurasia. Many phylogenetic studies have demonstrated the Indian subcontinent brought with it an array of endemic faunas that evolved in situ during its journey, suggesting this isolated subcontinent served as a source of biodiversity subsequent to its collision with Eurasia. However, recent molecular studies suggest that Eurasia may have served as the faunal source for some of India’s biodiversity, colonizing the subcontinent through land bridges between India and Eurasia during the early to middle Eocene (~35–40 MYA). In this study we investigate whether the Draconinae subfamily of the lizard family Agamidae is of Eurasian or Indian origin, using a multi locus Sanger dataset and a novel dataset of 4536 ultraconserved nuclear element loci.ResultsResults from our phylogenetic and biogeographic analyses revealed support for two independent colonizations of India from Eurasian ancestors during the early to late Eocene prior to the subcontinent’s hard collision with Eurasia.ConclusionThese results are consistent with other faunal groups and new geologic models that suggest ephemeral Eocene land bridges may have allowed for dispersal and exchange of floras and faunas between India and Eurasia during the Eocene.

Amphibians and Reptiles of Luzon Island (Philippines), VII: Herpetofauna of Ilocos Norte Province, Northern Cordillera Mountain Range

We report new distribution records for amphibians and reptiles from 20 localities within the northern Cordillera Mountain Range of Ilocos Norte Province, Luzon Island, Philippines. Together with opportunistic collections of specimens from past surveys, our new data result in a total of 58 amphibian and reptile species for Ilocos Norte Province and the extreme northern Cordilleras—all of which constitute major geographic range extensions. We utilize new data and IUCN formalized conservation assessment criteria to revise the conservation status of many species. Our results highlight the degree to which fundamental distribution data are lacking for Luzon amphibians and reptiles and emphasize the manner in which many current species assessments are based on incomplete data and, as a result, may be sorely misleading. The complex biogeography of Luzon’s herpetofauna remains poorly understood, providing opportunities for future research and conservation efforts once distribution patterns and local abundances are properly documented.

A New Species of Stream Frog (Sanguirana) from the Mountains of Luzon Island, Philippines

Abstract:  We describe a distinctively patterned new species of cascade stream frog from the mountains of Nueva Vizcaya and Aurora provinces, Luzon Island. The new species belongs to the genus Sanguirana, the definition of which we expand to include all Philippine species previously referred to the Rana (Hylarana) everetti complex. The new species is distinguished from other members of the genus by its possession of a bright yellow-green dorsum with conspicuous orange flower-shaped spots in females, bright white, postaxial dermal flanges on the limbs, green-to-purple flank transition, and a highly tuberculate, white venter, in addition to the absence of a dark canthal stripe. The new species is known only from high-gradient, cascading mountain streams between elevations of 750 and 1450 m in mature secondary forest and minimally disturbed primary forests. The discovery of such a distinctive new species emphasizes the relatively high degree to which endemic anuran diversity in the Philippines is still underestimated and underappreciated.

A new species of Trachylepis (Squamata: Scincidae) from Central Africa and a key to the Trachylepis of West and Central Africa

A new species of skink, Trachylepis gonwouoi sp. nov. is described from Cameroon and the Republic of the Congo. It differs from all other species of Trachylepis in Central-West Africa by a combination of number of keels on dorsal scales (3-5); moderate SVL (maximum size of 80 mm); number of scale rows at midbody (28-34); number of supracilliaries (6-10); a well defined lateral white stripe, bordered by black, extending from under the eye to the insertion of the hind limb; and a ventral color in life of bright blue-green. Trachylepis gonwouoi sp. nov. was found in association with disturbed forest at elevations from 50 to 1050m. This species is syntopic with T. affinis and T. maculilabris. In order to aid in the identification of Trachylepis in West and Central Africa with the addition of T. gonwouoi sp. nov., we provide an updated key to the Trachylepis found from Mauritania through the Democratic Republic of the Congo. This key combines previous literature that treated Western and Central African taxa separately and represents the most comprehensive key for Trachylepis in West-Central Africa to date.