Diversification of bent-toed geckos (Cyrtodactylus) on Sumatra and west Java.

Complex geological processes often drive biotic diversification on islands. The islands of Sumatra and Java have experienced dramatic historical changes, including isolation by marine incursions followed by periodic connectivity with the rest of Sundaland across highland connections. To determine how this geological history influenced island invasions, we investigated the colonization history and diversification of bent-toed geckos (genus Cyrtodactylus) on Sumatra and west Java. We used mitochondrial and nuclear sequence data to explore species boundaries, estimate phylogenetic relationships and divergence times, and to reconstruct ancestral range evolution. We found that Sumatran and Javan Cyrtodactylus were closely related to species from the Thai-Malay Peninsula, rather than from Borneo, and that Cyrtodactylus most likely dispersed to Sumatra three times during the late Oligocene and early Miocene. Similarly, Cyrtodactylus invaded west Java from Sumatra once in the early Miocene. Our results suggest that despite isolation by marine incursions during much of the Miocene, Cyrtodactylus dispersed to and from Sumatra and west Java likely via land bridges, and that in situ diversification occurred several times on Sumatra.

Genetic diversity of Tomistoma schlegelii inferred from mtDNA markers.

The genetic diversity of the endangered crocodile Tomistoma schlegelii was characterized using the protein coding ND 6-tRNA(glu)-cyt b and the cytochrome b-control region (cyt b-CR) markers. Concatenate data revealed six haplotypes with an overall haplotype diversity of 0.769 ± 0.039; nucleotide diversity was 0.00535 ± 0.00172. A nearest-neighbor analysis showed that all individuals clustered with four geographic regions (Sumatra, Peninsular Malaysia, Sarawak, and East Kalimantan) and were genetically differentiated. With the exception of the individuals from haplotype H2, which occurred in both Peninsular Malaysia and Sarawak, all other haplotypes were geographically distinct. The H4 lineage, which was found to be the most divergent, clustered exclusively in the basal clade in all phylogenetic trees, and the haplotype network was unconnected at the 95% reconnection limit, suggesting further investigation to establish its possible status as a distinct evolutionary significant unit or a cryptic species.

Another New Bent-toed Gecko, genus Cyrtodactylus Gray 1837 (Squamata: Gekkonidae), from Borneo.

To reveal the diversity of Indonesian bent-toed geckos, we pay attention to Kalimantan (Borneo)an island which has received less attention than other Indonesian islands such as Sumatra, Java, Sulawesi, the Moluccas, and the Lesser Sunda archipelagos. About 30 years after Hikida (1990) described three new Cyrtodactylus from Borneo, four more species were described, namely C. limajalur and C. muluensis in 2019, and C. hantu and C. miriensis in 2021, all by Davis et al. Through examination of the collection at MZB and three addition specimens collected from Tawau, we found several undescribed species, one of which we describe here. This new species is easily differentiated from all other congeners by the combination of the following characters: maximum SVL of at least 65.8 mm; no tubercles on dorsal surface of upper arm; tubercles present in the ventrolateral body folds; 2830 paravertebral tubercles; 1720 longitudinal dorsal tubercle rows; 3946 ventral scale rows at midbody; 1719 subdigital lamellae on fourth toe; precloacal pit with 57 pores in males arranged in a wide -shape but absent in females; no enlarged transverse median subcaudals; paired dark brown semilunar-shaped markings on the upper nape. Further study is needed to reveal its molecular phylogenetic position and biogeographical history.

Hidden in the plain sight: a new species of Rhabdophis (Serpentes: Natricinae) from the Rhabdophis himalayanus complex.

A new species of natricine snake of the genus Rhabdophis is described from Northeast India. Morphologically the new species is similar to Rhabdophis himalayanus but it can be distinguished from it by lacking a nuchal groove and nuchal glands, being relatively smaller, and having a distinct neck, ventral, and subcaudal coloration. In overall coloration it resembles R. chrysargos, from which it is distinguished by several aspects of its morphology and genetic differences. The discovery of Rhabdophis bindi sp. nov. reveals that forested regions in the northeastern part of India needs further biological exploration.

A new species of Megophrys Kuhl amp; Van Hasselt (Amphibia: Megophryidae) from Borneo allied to M. nasuta (Schlegel, 1858).

Within Sundaland, the species diversity of the genus Megophrys is richest in Borneo, with some species restricted to the northern highlands of the island. On the basis of molecular, morphological and acoustic evidence, we describe a new species of large-sized Megophrys, once confused with M. nasuta. The new species Megophrys kalimantanensis sp. nov. can be differentiated from all its congeners by large genetic distance more than 6.11% in the mitochondrial 16S rRNA gene, much shorter rostral and orbital appendages, and unique advertisement call. This new species has been recorded from medium to high altitudes of mountain forest in southern and northernmost Borneo.

New species, diversity, systematics, and conservation assessment of the Puppet Toads of Sumatra (Anura: Bufonidae: Sigalegalephrynus).

Using a combination of morphological and molecular data we recognize three new species of Puppet Toad, Sigalegalephrynus Smart, Sarker, Arifin, Harvey, Sidik, Hamidy, Kurniawan Smith, a recently described genus endemic to the highland forests of Sumatra, Indonesia. Phylogenetic analysis of mitochondrial DNA sequences recovered a monophyletic relationship among all Puppet Toads, with two distinct evolutionary clades, a northern and a southern. The northern clade includes Sigalegalephrynus gayoluesensis sp. nov., and S. burnitelongensis sp. nov., and the southern clade includes S. harveyi sp. nov., S. mandailinguensis, and S. minangkabauensis. With the discovery of these three new species, Sigalegalephrynus contains more endemic species than any other genus of toad in Indonesia. We used maximum entropy, implemented in MaxEnt, to identify suitable habitats and occurrence probability of additional undescribed new species from the island. The most important predictors of Sigalegalephrynus distribution were elevation (64.5%) and land cover (7.11%). Based on the probability of presence, it is likely that there are many more species of the genus awaiting discovery in Sumatra. Our analysis, based on IUCN Red List of Threatened Species category and criteria, shows that all of the five species of Sigalegalephrynus are in great risk of extinction and should be placed into the Endangered (EN) category of IUCN Red List.

A new species of Rock Gecko of the genus Cnemaspis Strauch, 1887 (Squamata: Gekkonidae) from Belitung Island, Indonesia.

A new species of rock gecko of the genus Cnemaspis Strauch is described from Belitung Island, Indonesia. The new species is differentiated from all other species in the Southern Sunda clade (sensu Grismer et al. 2014a) by having a unique combination of characters including: (1) a maximum SVL of 54.1 mm, (2) five or six postmental scales, (3) enlarged submetacarpal scales on the first finger, (4) enlarged submetatarsal scales on the first toe, (5) keeled ventral scales, (6) absence of precloacal pores, (7) absence of enlarged femoral scales, (8) absence of shield-like subtibial scales, (9) caudal tubercles encircling the tail, (10) an interrupted median row of enlarged keeled subcaudals, (11) presence of a distinct furrow on the lateral surface of the tail (12) 22-24 lamellae beneath fourth toe, and (13) two postcloacal tubercles on each side of the tail base.