Bewildering biogeography: Waves of dispersal and diversification across southern Wallacea by bent-toed geckos (genus: Cyrtodactylus).

Bent-toed Geckos, genus Cyrtodactylus, are one of the most diverse terrestrial vertebrate groups, and their range extends from South Asia into Australo-Papua and adjacent Pacific islands. Given the generally high faunal endemism on Wallacean islands, it is rather paradoxical that the diversity in these geckos appears to be so low (21 species in Wallacea, 15 in the Philippines) compared with continental shelf assemblages (>300 species on Sunda + Sahul Shelves + adjacent islands). To determine whether this shortfall was real or an artifact of historical undersampling, we analyzed mitochondrial DNA sequences of hundreds of southern Wallacean samples (Lesser Sundas + southern Maluku). After screening to guide sample selection for target capture data collection, we obtained a 1150-locus genomic dataset (1,476,505 bp) for 119 samples of southern Wallacean and closely related lineages. The results suggest that species diversity of Cyrtodactylus in southern Wallacea is vastly underestimated, with phylogenomic and clustering analyses suggesting as many as 25 candidate species, in contrast to the 8 currently described. Gene exchange between adjacent candidate species is absent or minimal across the archipelago with only one case of > 0.5 migrants per generation. Biogeographical analysis suggests that the hitherto unrecognized diversity is the result of at least three independent dispersals from Sulawesi or its offshore islands into southern Wallacea between 6 and 14 Ma, with one invasion producing small-bodied geckos and the other two or three producing larger-bodied geckos. The smaller-bodied laevigatus group appears to be able to coexist with members of either larger-bodied clade, but we have yet to find members of the two larger-bodied clades occurring in sympatry, suggesting that ecological partitioning or competitive exclusion may be shaping individual island assemblages.

Ticks (Acari: Ixodidae) of three Timor-Leste reptiles: first country record of Amblyomma helvolum, with new interactions and an updated list of host species.

We report on the presence of the ixodid tick Amblyomma helvolum on three species of reptiles from Timor-Leste. Among a total of 21 host specimens (lizards: 18 four-fingered skinks, Carlia sp. 'Meleotegi' and two forest skinks, Sphenomorphus sp. 'Meleotegi'; snake: one Coelognathus subradiatus) four were parasitized by ticks. Whereas nymphs were associated with the lizards, an adult male was retrieved from the snake. This report is the first of A. helvolum for Timor-Leste, the first for the skink genera Carlia and Sphenomorphus, and the first for C. subradiatus. We present a comprehensive table with updated taxonomy of known associations between A. helvolum and other vertebrates.

Phylogenetic relationships of southern Wallacean ranid frogs (Anura: Ranidae: Hylarana).

Frogs in the family Ranidae are diverse in Asia and are thought to have dispersed to the Sahul Shelf approximately 10 million years ago, where they radiated into more than a dozen species. Ranid species in the intervening oceanic islands of Wallacea, such as Hylarana florensis and H. elberti from the Lesser Sundas and H. moluccana from eastern Wallacea, are assumed to belong to the subgenus Papurana, yet this has not been confirmed with molecular data. We analyzed mitochondrial DNA of Hylarana species from five islands spanning the reported ranges of H. florensis and H. elberti and compared them to confirmed Papurana species and closely related subgenera within Hylarana. We find that the Lesser Sunda H. florensis and H. elberti form a clade that is sister to the rest of the Australo-Papuan Papurana assemblage. Species delimitation analyses and divergence time estimates suggest that populations of H. florensis on Lombok may be distinct from those on Flores at the species level. Likewise, populations of H. elberti on Sumba and Timor may be distinct from each other and from those on Wetar, tshe type locality of H. elberti. Samples from Babar Island thought to be members of H. elberti in fact belong to the wide-ranging H. daemeli, which occurs in northern Australia, across New Guinea, and on the neighboring island of Tanimbar. These results suggest that the Lesser Sundas may have served as a stepping-stone for colonization of the Sahul Shelf and that species diversity of Papurana frogs is underestimated in the Lesser Sundas.

Diverge and Conquer: Phylogenomics of southern Wallacean forest skinks (Genus: Sphenomorphus) and their colonization of the Lesser Sunda Archipelago.

The archipelagos of Wallacea extend between the Sunda and Sahul Shelves, serving as a semipermeable two-way filter influencing faunal exchange between Asia and Australo-Papua. Forest skinks (Genus Sphenomorphus) are widespread throughout southern Wallacea and exhibit complex clinal, ontogenetic, sexual, and seasonal morphological variation, rendering species delimitation difficult. We screened a mitochondrial marker for 245 Sphenomorphus specimens from this area to inform the selection of 104 samples from which we used targeted sequence capture to generate a dataset of 1154 nuclear genes (∼1.8 Mb) plus complete mitochondrial genomes. Phylogenomic analyses recovered many deeply divergent lineages, three pairs of which are now sympatric, that began to diversify in the late Miocene shortly after the oldest islands are thought to have become emergent. We infer a complex and nonstepping-stone pattern of island colonization, with the group having originated in the Sunda Arc islands before using Sumba as a springboard for colonization of the Banda Arcs. Estimates of population structure and gene flow across the region suggest total isolation except between two Pleistocene Aggregate Island Complexes that become episodically land-bridged during glacial maxima. These historical processes have resulted in at least 11 Sphenomorphus species in the region, nine of which require formal description. This fine-scale geographic partitioning of undescribed species highlights the importance of utilizing comprehensive genomic studies for defining biodiversity hotspots to be considered for conservation protection.

Threes Company: discovery of a third syntype of Stegonotus lividus, a species of colubrid snake from Pulau Semau, Lesser Sunda Islands, Indonesia, with comments on an unpublished 19th Century manuscript by the naturalist Salomon Mller.

We report on the discovery of a third, male specimen of Stegonotus lividus in the collection of the Musum National dHistoire Naturelle in Paris, France, and demonstrate that it is not only a member of the original type series but the only one of the three syntypes, whose morphology was detailed in the original description. We herein identify it as a paralectotype. In their description of S. lividus, Dumril et al. (1854) attributed authorship of the name to the German zoologist Salomon Mller, whose work was never published. By the rules of zoological nomenclature, author attribution solely via an unpublished manuscript is inadmissible, and the species is therefore properly listed as Stegonotus lividus (Dumril et al., 1854). The recent discovery of Mllers handwritten manuscript, along with an unpublished drawing of one of these snakes by the Dutch artist Pieter van Oort, allows a better assessment of color and pattern for a species that remains known from only three preserved vouchers, as well as improved differentiation from other taxa occurring in the Lesser Sundas and Moluccas.

A new species of Stegonotus (Serpentes: Colubridae) from the remnant coastal forests of southern Timor-Leste.

During the first amphibian and reptile survey of Timor-Leste, we discovered a population of groundsnakes, genus Stegonotus, in the last remnant of lowland coastal forest along the countrys southern coast, which represents a new species. This sexually dimorphic species can be differentiated from all other Wallacean Stegonotus by a combination of 17-17-15 dorsals, ventrals (female 206; males 197207), paired subcaudals (female 61; males 7175), the gull wing + condition of the rostral, large squared prefrontals that each are 2.5 times the area of the internasals and two-thirds the size of the frontal, a snout-scale ratio of near 0.4 and a frontal-parietal suture ratio of ≤ 1.0, a labial scale formula of 73+4 | 94, five gulars separating the posterior genial and the anteriormost ventral, and an overall brown body coloration that lightens progressively from the vertebral scale row in a dorsallateral direction and features color gradients of dark brown posterior edges to lighter brown anterior edges on individual scales. The species is most similar in overall morphology to S. modestus from the central Moluccas and to S. lividus, a species known only from tiny Semau Island that lies off the western end of Timor Island, in close proximity to Kupang, the capital of the Indonesian province of East Nusa Tenggara.

Phylogenomic Analysis Reveals Dispersal-Driven Speciation and Divergence with Gene Flow in Lesser Sunda Flying Lizards (Genus Draco).

The Lesser Sunda Archipelago offers exceptional potential as a model system for studying the dynamics of dispersal-driven diversification. The geographic proximity of the islands suggests the possibility for successful dispersal, but this is countered by the permanence of the marine barriers and extreme intervening currents that are expected to hinder gene flow. Phylogenetic and species delimitation analyses of flying lizards (genus Draco) using single mitochondrial genes, complete mitochondrial genomes, and exome-capture data sets identified 9-11 deeply divergent lineages including single-island endemics, lineages that span multiple islands, and parapatrically distributed nonsister lineages on the larger islands. Population clustering and PCA confirmed these genetic boundaries with isolation-by-distance playing a role in some islands or island sets. While gdi estimates place most candidate species comparisons in the ambiguous zone, migration estimates suggest 9 or 10 species exist with nuclear introgression detected across some intra-island contact zones. Initial entry of Draco into the archipelago occurred at 5.5-7.5 Ma, with most inter-island colonization events having occurred between 1-3 Ma. Biogeographical model testing favors scenarios integrating geographic distance and historical island connectivity, including an initial stepping-stone dispersal process from the Greater Sunda Shelf through the Sunda Arc as far eastward as Lembata Island. However, rather than reaching the adjacent island of Pantar by dispersing over the 15-km wide Alor Strait, Draco ultimately reached Pantar (and much of the rest of the archipelago) by way of a circuitous route involving at least five overwater dispersal events. These findings suggest that historical geological and oceanographic conditions heavily influenced dispersal pathways and gene flow, which in turn drove species formation and shaped species boundaries. [Biogeography; genomics, Indonesia; lizards; phylogeography; reptiles].

An evaluation of the nomina for death adders (Acanthophis Daudin, 1803) proposed by Wells amp; Wellington (1985), and confirmation of A. cryptamydros Maddock et al., 2015 as the valid name for the Kimberley death adder.

We assess the availability of four names proposed by Wells Wellington (1985) for Australian death adders (Acanthophis). In agreement with previous literature, A. hawkei is an available name, whereas A. armstrongi, A. lancasteri, and A. schistos are not described in conformity with the requirements of Articles 13.1.1 or 13.1.2 of the International Code of Zoological Nomenclature and are therefore considered nomina nuda. Consequently, A. cryptamydros Maddock et al., 2015, is confirmed as the valid name for the Kimberley death adder of Western Australia. We comment on the need for greater clarity in the Code, and emphasise that the responsibility for establishing the availability of new nomina rests with their authors, not subsequent researchers.

Carefully examining Bornean Stegonotus (Serpentes, Colubridae): the montane groundsnake population in Sabah is a new and distinct species.

During a taxonomic revision of species in the genus Stegonotus Duméril et al., 1854, we re-examined over 90% of all known museum specimens from this taxon. Of the five specimens available to us from the island of Borneo, three are clearly distinct from the other two. The latter are from the lowland rainforest in Sarawak, Malaysia, which includes the type locality of S. borneensis, and therefore these specimens retain that name. We here describe the other three, which include the paratype of S. borneensis, as a new species from Sabah, Malaysia. The new species can be differentiated from S. borneensis and all other species of Stegonotus by the combination of a high number of ventrals ( 210) combined with a low number of subcaudals ( 70), a short tail (indicated by a low subcaudal ratio of 0.25), 17-17-15 dorsal scale rows, a snout-scale ratio of 1/4-1/3, the "gull wing +" condition of the rostral, the number of supralabials touching the eye, and a dorsal color pattern featuring a dark gray-brown head offset from a lighter-brown rest of the body. The number of subcaudals in the holotype of the new species is only 21% of the number of ventrals, the lowest proportion in the genus. The new species is found at elevations above 1000 m in the cool, montane habitats of the Crocker Range and around the foot of Mt. Kinabalu, Southeast Asia's tallest mountain, from where it has been known but taxonomically unrecognized since at least the 1880s.

Molecular phylogeny of Asian pipesnakes, genus Cylindrophis Wagler, 1828 (Squamata: Cylindrophiidae), with the description of a new species from Myanmar.

Cylindrophis is a genus of secretive, semi-fossorial, non-venomous snakes comprising 14 species, characterized by a generally cylindrical body, uniform scales (with barely enlarged ventrals), and vestiges of pelvic and limb bones, the latter terminating in a claw lateral to the vent. We reconstructed a concatenated molecular phylogeny of seven taxa of Cylindrophis taxa based on one nuclear (R35) and two mitochondrial (16S, ND2) genes. Analyses recovered the Sri Lankan endemic C. maculatus as sister to all other sampled Cylindrophis. The mainland Southeast Asian species C. burmanus and C. jodiae form successive sister lineages to a monophyletic Wallacean island group containing C. boulengeri, C. isolepis, and C. yamdena. We also describe a new species of Cylindrophis, morphologically similar to C. burmanus, from Kachin State in northern Myanmar. Cylindrophis slowinskii sp. nov. is distinguished from all congeners by the following combination of characters: 19 dorsal scale rows at midbody, 216-220 ventrals, eight subcaudals, a dark venter with > 60 very narrow diffuse pale blotches, and a pale bar running along the posterior border of the prefrontals. In our phylogeny, the new species is strongly supported as the sister species of C. burmanus. It is the 15th currently recognised species in the genus, and the fourth from mainland Southeast Asia.

The purportedly Indo-Australian gecko species Cnemaspis timoriensis (Duméril amp; Bibron, 1836) is actually the first named species of the neotropical genus Gonatodes Fitzinger, 1843 (Squamata: Gekkonidae).

Only a single known specimen of Cnemaspis timoriensis (Duméril Bibron, 1836) exists, the holotype in the Muséum National d'Histoire Naturelle in Paris, France. Purportedly collected by Charles Gaudichaud-Beaupré in the year 1818 on Timor Island in the Lesser Sunda Archipelago during the circumnavigation of the globe by the vessel L'Uranie, intensive research on Timor has failed to produce additional specimens or any similarly appointed gecko. Using a series of detailed morphological comparisons, we provide irrefutable evidence that the animal in question is not a member of Cnemaspis but of the neotropical genus Gonatodes. Furthermore, we ascertained that C. timoriensis is conspecific with G. humeralis, a widely distributed South American species. We also show that a specimen labeled with the timoriensis name in the Museum für Naturkunde, Berlin, Germany is not conspecific and not part of a type series. While the taxon name timoriensis has nomenclatural priority over the two-decades-younger name humeralis, usage would dictate that to preserve the nomenclatural stability of neotropical geckos the junior synonym should be retained. An application to the International Commission on Zoological Nomenclature to this effect is in preparation.

A new species of Indo-Papuan groundsnake, genus Stegonotus Duméril et al., 1854 (Serpentes, Colubridae), from the Bird's Head Peninsula of West Papua, Indonesia, with comments on differentiating morphological characters.

We describe a new species of Indo-Papuan groundsnake (Stegonotus) from a single adult male specimen collected in 1953 near Kamro, a village in Maybrat Regency, West Papua, Indonesia. The specimen had been considered a member of S. batjanensis, a well-defined species from the northern Maluku Islands over 500 km to the northwest with which it shares the key characteristic of having the 3rd, 4th, and 5th supralabial scales touching the eyes. The new species can be differentiated from S. batjanensis as well as all other species of Stegonotus by having its 5th supralabial scale projecting forward from behind the eye to form a narrow contact zone with the eye. In addition, it is differentiated by the combination of the following characteristics: seven supralabials, the 3rd-5th touching the eye; eight infralabials, the 1st-4th touching the anterior genial; four scales separating the posterior genial and the first gastrostege; dorsal scales in 17 rows, diminishing to 15 posteriorly; a low number of ventrals (181 in the holotype) combined with a high number of subcaudals (105 in the holotype), the latter comprising 37% of the scales on the ventral surface, the highest proportion in the genus. The description of this species is of interest beyond adding to the species diversity of Stegonotus: it allowed us to explore additional characteristics to resolve taxonomic questions in a morphologically conservative genus, it illustrates the need for additional herpetological survey work on the Bird's Head Peninsula, and its initial misidentification serves as a reminder of the continued relevance and importance of natural history collections as repositories for specimens and data that influence our knowledge today by reaching out from the past.

Corrigenda and Addenda to the Article "The taxonomic history of Indo-Papuan groundsnakes, genus Stegonotus Duméril et al., 1854 (Colubridae), with some taxonomic revisions and the designation of a neotype for S. parvus (Meyer, 1874)" by Kaiser et al. (2018).

Kaiser et al. (2018) recently presented a comprehensive history of snakes in the genus Stegonotus Duméril et al., 1854 that included substantial taxonomic revisions. Given the scope and production of this work a few issues remained uncorrected during several proof stages, which we correct herein. Furthermore, after the paper was published some relevant information emerged that we do not want to leave unexposed, and which we hereby add to our discussion.

The taxonomic history of Indo-Papuan groundsnakes, genus Stegonotus Duméril et al., 1854 (Colubridae), with some taxonomic revisions and the designation of a neotype for S. parvus (Meyer, 1874).

Since its conceptualization in 1854, 29 species of the colubrid genus Stegonotus have been recognized or described, of which 15 (admiraltiensis, batjanensis, borneensis, cucullatus, derooijae, diehli, florensis, guentheri, iridis, heterurus, melanolabiatus, modestus, muelleri, parvus, poechi) are still considered valid today. Original species descriptions for the members of this genus were published in Dutch, English, French, German, and Italian and, perhaps as a consequence of these polyglot origins, there has been a considerable amount of confusion over which species names should be applied to which populations of Stegonotus throughout its range across Borneo, the Philippines, Wallacea, New Guinea, Australia, and associated archipelagos. In addition, the terminology used to notate characteristics in the descriptions of these forms was not uniform and may have added to the taxonomic confusion. In this paper, we trace in detail the history of the type specimens, the species, and the synonyms currently associated with the genus Stegonotus and provide a basic, species-specific listing of their characteristics, derived from our examination of over 1500 museum specimens. Based on our data, we are able to limit the distribution of S. modestus to the islands of Ambon, Buru, and Seram in the central Moluccas of Indonesian Wallacea. We correct the type locality of S. cucullatus to the Manokwari area on the Bird's Head Peninsula of West Papua, Indonesian New Guinea and designate a neotype for S. parvus, a species likely to be a regional endemic in the Schouten Archipelago of Cenderawasih Bay (formerly Geelvink Bay), Indonesian New Guinea. We unequivocally identify and explain the problematic localities of the type specimens of S. muelleri and Lycodon muelleri, which currently reside in the same specimen jar. We remove L. aruensis and L. lividum from the synonymy of S. modestus and recognize them as S. aruensis n. comb. and S. lividus n. comb., respectively. We remove S. keyensis and Zamenophis australis from the synonymy of S. cucullatus and recognize them as S. keyensis n. comb. and S. australis n. comb., respectively. We further remove S. reticulatus from the synonymy of S. cucullatus, S. dorsalis from the synonymy of S. diehli, and S. sutteri from the synonymy of S. florensis. We designate lectotypes for S. guentheri, S. heterurus, S. lividus, and S. reticulatus. Lastly, we introduce S. poechi, a valid species not mentioned in the scientific literature since its description in 1924. This brings the diversity in the genus Stegonotus to 22 species. We also caution that in a complex group of organisms like Stegonotus any rush to taxonomic judgment on the basis of molecular and incomplete morphological data sets may perpetuate errors and introduce incongruities. Only through the careful work of connecting type material with museum specimens and molecular data can the taxonomy and nomenclature of complex taxa be stabilized.

A new species of Cylindrophis Wagler, 1828 (Reptilia: Squamata: Cylindrophiidae) from Boano Island, northern Maluku Province, Indonesia.

 We describe a new species of snake of the genus Cylindrophis Wagler, 1828 from Boano Island, northern Maluku         Province, Indonesia. Cylindrophis osheai sp. nov. differs from all congeners by a combination of the following eidonomic characters: (1) 19 dorsal scale rows at midbody; (2) 224-226 ventral scales; (3) 8-9 subcaudal scales; (4) 25-28 dark ventral blotches, aligned to form a broad, wavy stripe along most of the body; (5) a dark ventral pattern that is completely separated from the dark dorsal coloration; (6) an almost completely dark ventral surface on the tail; (7) a dark bar running from the eye through the 3rd and 4th supralabials to the mouth; and (8) a dark, double-diamond-shaped ventral blotch in the area immediately posterior to the genials. Eidonomic species separation from other Cylindrophis species is supported by differences in cranial osteology, as elucidated by micro-computed tomography images. Diagnostic features of the cranium include (1) well-developed postorbitofrontals that project laterally beyond the maxilla in dorsal view, creating a characteristic, horn-like appearance; (2) a broad parietal with a bulbous middle section; (3) 10-12 maxillary teeth; (4) nine        palatine teeth; (5) 7-9 teeth on the pterygoid; and (6) 11-13 teeth on the dentary. We also provide notes on the taxonomic history of Cylindrophis melanotus Wagler, 1828 and an identification key to the Moluccan species of the genus.

A new small bent-toed gecko of the genus Cyrtodactylus (Squamata: Gekkonidae) from the lower slopes of Mount Tambora, Sumbawa Island, Indonesia.

We describe the sixth species of bent-toed gecko from the Lesser Sunda Islands, Indonesia. This species was first collected on the banks of the Oi Marai River on the low northern slopes of Gunung (Mount) Tambora on Sumbawa Island. The new species is differentiated from Greater Sunda Islands (including Sulawesi) and Lesser Sunda Islands congeners by having the following unique combination of characters: (1) two scales between the second pair of postmentals in contact with the first pair; (2) dorsal surface of antebrachium tuberculate; (3) no tubercles on dorsal surface of brachium; (4) dorsal surfaces of thigh and crus tuberculate; (5) 18 irregularly aligned, longitudinal rows of keeled tubercles at midbody; (6) 26-27 paravertebral tubercles; (7) 40 ventral scales between indistinct ventrolateral folds; (8) 16-17 fourth-toe subdigital scales; (9) a continuous enlarged precloacal and femoral scales present, with the enlarged femoral scales arranged in three rows; (10) males with five to six precloacal pores, with four larger pores situated in a short groove; (11) femoral pores absent in both sexes; (12) lack of transversely enlarged subcaudal scales; and (13) 7-9 irregular, paired black blotches on the body.

Historical considerations and comments on the type series of Cyrtodactylus marmoratus Gray, 1831, with an updated comparative table for the bent-toed geckos of the Sunda Islands and Sulawesi.

Cyrtodactylus marmoratus Gray, 1831, a species of bent-toed gecko exhibiting a precloacal groove in males, was described on the basis of specimens collected by Heinrich Kuhl and Johan Conrad van Hasselt in Java, Greater Sunda Islands, Indonesia. Kluge (1985) subsequently designated a lectotype for C. marmoratus from a series of these specimens (i.e., syntypes), now housed in the herpetological collection at Naturalis (formerly the Rijksmuseum van Natuurlijke Historie; RMNH), Leiden, the Netherlands. Our work at Naturalis shows that the type series of C. marmoratus at RMNH actually comprises two sets of specimens, and that examination of specimens from one set or the other by different authors, including Kluge (1985), is responsible for some confusion surrounding the type series of this species. As a consequence, we present relevant morphological data for all 14 specimens constituting the type series of C. marmoratus at RMNH for the first time. The type status of two specimens of C. marmoratus in the collection at the Muséum National d'Histoire Naturelle, Paris, France, remains unresolved at present. Owing to the inconsistent naming and application of terms for some key characters (e.g., groove, sulcus, pit, hollow, depression) used in the diagnoses of Cyrtodactylus species, we here propose a set of novel and useful definitions that are supported by photographs. We also illustrate the sexually dimorphic expression of this character in C. marmoratus. Finally, we present a revised comparative table for the bent-toad geckos of the Sunda Islands and Sulawesi.

An inconspicuous, conspicuous new species of Asian pipesnake, genus Cylindrophis (Reptilia: Squamata: Cylindrophiidae), from the south coast of Jawa Tengah, Java, Indonesia, and an overview of the tangled taxonomic history of C. ruffus (Laurenti, 1768).

We describe a new species of Cylindrophis currently known only from Grabag, Purworejo Regency, Jawa Tengah Pro-vince (Central Java), Java, Indonesia. Cylindrophis subocularis sp. nov. can be distinguished from all congeners by the presence of a single, eponymous subocular scale between the 3rd and 4th or 4th and 5th supralabial, preventing contact between the 4th or 5th supralabial and the orbit, and by having the prefrontal in narrow contact with or separated from the orbit. We preface our description with a detailed account of the tangled taxonomic history of the similar and putatively wide-ranging species C. ruffus, which leads us to (1) remove the name Scytale scheuchzeri from the synonymy of C. ruffus, (2) list the taxon C. rufa var. javanica as species inquirenda, and (3) synonymize C. mirzae with C. ruffus. We provide additional evidence to confirm that the type locality of C. ruffus is Java. Cylindrophis subocularis sp. nov. is the second species of Asian pipesnake from Java.

A new species of bent-toed gecko, genus Cyrtodactylus Gray, 1827 (Reptilia: Squamata: Gekkonidae), from Jawa Timur Province, Java, Indonesia, with taxonomic remarks on C. fumosus (Müller, 1895).

A new species of the gekkonid lizard genus Cyrtodactylus Gray, 1827 is described from Klakah, Lumajang Regency, Jawa Timur Province, Java, Indonesia. Cyrtodactylus klakahensis sp. nov. can be distinguished from all other congeners by the presence of (1) a deep precloacal groove in males, (2) three rows of enlarged precloacofemoral scales, of which the third row bears 37-38 pores in males, (3) three or four rows of enlarged scales between the precloacofemoral scale rows and the cloaca, forming distinct chevrons, (4) raised and strongly keeled dorsal tubercles in 15-19 rows at midbody, (5) an indistinct lateral fold, (6) 17-20 subdigital lamellae under the 4th toe, and (7) subcaudal scales which are not transversely enlarged. Cyrtodactylus klakahensis sp. nov. is only the third bent-toed gecko species described from Java, indicating that the diversity of this genus on this island has been neglected in the past. Furthermore, we confirm that C. fumosus (Müller, 1895) is a species that possesses a precloacal groove in males and is most likely restricted to northern Sulawesi. That species is defined by a single female holotype (NMB-REPT 2662). Specimens in museum collections catalogued as C. fumosus from localities elsewhere are misidentified and likely represent undescribed species.