Integrative methods reveal multiple drivers of diversification in rice paddy snakes.

Divergence dating analyses in systematics provide a framework to develop and test biogeographic hypotheses regarding speciation. However, as molecular datasets grow from multilocus to genomic, sample sizes decrease due to computational burdens, and the testing of fine-scale biogeographic hypotheses becomes difficult. In this study, we use coalescent demographic models to investigate the diversification of poorly known rice paddy snakes from Southeast Asia (Homalopsidae: Hypsiscopus), which have conflicting dates of origin based on previous studies. We use coalescent modeling to test the hypothesis that Hypsiscopus diversified 2.5 mya during the Khorat Plateau uplift in Thailand. Additionally, we use ecological niche analyses to identify potential differences in the niche space of the two most widely distributed species in the past and present. Our results suggest Hypsiscopus diversified ~ 2.4 mya, supporting that the Khorat Plateau may have initiated the diversification of rice paddy snakes. We also find significant niche differentiation and shifts between species of Hypsiscopus, indicating that environmental differences may have sustained differentiation of this genus after the Khorat Plateau uplift. Our study expands on the diversification history of snakes in Southeast Asia, and highlights how results from smaller multilocus datasets can be useful in developing and testing biogeographic hypotheses alongside genomic datasets.

DNA barcoding of Chinese snakes reveals hidden diversity and conservation needs.

DNA barcoding has greatly facilitated studies of taxonomy, biodiversity, biological conservation, and ecology. Here, we establish a reliable DNA barcoding library for Chinese snakes, unveiling hidden diversity with implications for taxonomy, and provide a standardized tool for conservation management. Our comprehensive study includes 1638 cytochrome c oxidase subunit I (COI) sequences from Chinese snakes that correspond to 17 families, 65 genera, 228 named species (80.6% of named species) and 36 candidate species. A barcode gap analysis reveals gaps, where all nearest neighbour distances exceed maximum intraspecific distances, in 217 named species and all candidate species. Three species-delimitation methods (ABGD, sGMYC, and sPTP) recover 320 operational taxonomic units (OTUs), of which 192 OTUs correspond to named and candidate species. Twenty-eight other named species share OTUs, such as Azemiops feae and A. kharini, Gloydius halys, G. shedaoensis, and G. intermedius, and Bungarus multicinctus and B. candidus, representing inconsistencies most probably caused by imperfect taxonomy, recent and rapid speciation, weak taxonomic signal, introgressive hybridization, and/or inadequate phylogenetic signal. In contrast, 43 species and candidate species assign to two or more OTUs due to having large intraspecific distances. If most OTUs detected in this study reflect valid species, including the 36 candidate species, then 30% more species would exist than are currently recognized. Several OTU divergences associate with known biogeographic barriers, such as the Taiwan Strait. In addition to facilitating future studies, this reliable and relatively comprehensive reference database will play an important role in the future monitoring, conservation, and management of Chinese snakes.

The phylogenetic status of Limnonectes liui (Yang, 1983) (Anura: Dicroglossidae) based on mitochondrial genes and its taxonomic implications.

Limnonectes liui (Yang, 1983) is a poorly known frog from Yunnan Province, China, with a confusing taxonomic history. We use mitochondrial (mt) DNA sequence data from newly collected specimens to reconstruct the phylogenetic position of the species. Limnonectes liui was found to be deeply nested within the geographically widespread dicroglossid frog L. limborgi (Sclater, 1892), verifying its placement within the genus Limnonectes but casting doubt on its distinction as a species. Morphological comparisons of the holotype and newly collected specimens of L. liui to specimens of L. limborgi from across its range also corroborated the hypothesis that these two species are conspecific, and we recommend treating L. liui as a junior synonym of L. limborgi. Our study underscores the importance of making comparisons with species found beyond a countrys border when describing new species.

A global reptile assessment highlights shared conservation needs of tetrapods.

Comprehensive assessments of species' extinction risks have documented the extinction crisis1 and underpinned strategies for reducing those risks2. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction3. Because global assessments have been lacking, reptiles have been omitted from conservation-prioritization analyses that encompass other tetrapods4-7. Reptiles are unusually diverse in arid regions, suggesting that they may have different conservation needs6. Here we provide a comprehensive extinction-risk assessment of reptiles and show that at least 1,829 out of 10,196 species (21.1%) are threatened-confirming a previous extrapolation8 and representing 15.6 billion years of phylogenetic diversity. Reptiles are threatened by the same major factors that threaten other tetrapods-agriculture, logging, urban development and invasive species-although the threat posed by climate change remains uncertain. Reptiles inhabiting forests, where these threats are strongest, are more threatened than those in arid habitats, contrary to our prediction. Birds, mammals and amphibians are unexpectedly good surrogates for the conservation of reptiles, although threatened reptiles with the smallest ranges tend to be isolated from other threatened tetrapods. Although some reptiles-including most species of crocodiles and turtles-require urgent, targeted action to prevent extinctions, efforts to protect other tetrapods, such as habitat preservation and control of trade and invasive species, will probably also benefit many reptiles.

Giant Tree Frog diversification in West and Central Africa: Isolation by physical barriers, climate, and reproductive traits.

Secondary sympatry amongst sister lineages is strongly associated with genetic and ecological divergence. This pattern suggests that for closely related species to coexist in secondary sympatry, they must accumulate differences in traits that mediate ecological and/or reproductive isolation. Here, we characterized inter- and intraspecific divergence in three giant tree frog species whose distributions stretch across West and Central Africa. Using genome-wide single-nucleotide polymorphism data, we demonstrated that species-level divergence coincides temporally and geographically with a period of large-scale forest fragmentation during the late Pliocene. Our environmental niche models further supported a dynamic history of climatic suitability and stability, and indicated that all three species occupy distinct environmental niches. We found modest morphological differentiation amongst the species with significant divergence in tympanum diameter and male advertisement call. In addition, we confirmed that two species occur in secondary sympatry in Central Africa but found no evidence of hybridization. These patterns support the hypothesis that cycles of genetic exchange and isolation across West and Central Africa have contributed to globally significant biodiversity. Furthermore, divergence in both ecology and reproductive traits appear to have played important roles in maintaining distinct lineages. At the intraspecific level, we found that climatic refugia, precipitation gradients, marine incursions, and potentially riverine barriers generated phylogeographic structure throughout the Pleistocene and into the Holocene. Further studies examining phenotypic divergence and secondary contact amongst these geographically structured populations may demonstrate how smaller scale and more recent biogeographic barriers contribute to regional diversification.

La sympatrie secondaire parmi les espèces sœurs est fortement associée à la divergence génétique et écologique. Ce modèle suggère que pour que des espèces étroitement liées coexistent en sympatrie secondaire, elles doivent accumuler des différences dans les traits qui contribuent à l'isolement écologique ou reproductif. Ici, nous avons caractérisé la divergence inter- et intra-spécifique chez trois espèces de grenouilles arboricoles géantes dont les distributions s'étendent à travers l'Afrique de l'Ouest et Centrale. Avec des données génétiques, nous avons démontré que la divergence au niveau des espèces coïncide temporellement et géographiquement avec une période de fragmentation forestière à la fin du Pliocène. Nos modèles de niches environnementales ont soutenu une histoire dynamique de stabilité climatique, et ont indiqué que les trois espèces occupent des niches environnementales distinctes. Nous avons trouvé une différenciation morphologique modeste parmi les trois espèces mais une divergence significative dans le diamètre du tympan et les cris des mâles. De plus, nous avons confirmé que deux espèces sont présentes en sympatrie secondaire en Afrique Centrale mais n'avons trouvé aucune preuve d'hybridation. Ces résultats soutiennent l'hypothèse que les cycles d'échange génétique et d'isolement à travers l'Afrique de l'Ouest et Centrale ont contribué à une profonde concentration de biodiversité dans la région. De plus, la divergence des traits écologiques et reproducteurs semble avoir joué un rôle important dans le maintien de lignées distinctes. Au niveau intra-spécifique, nous avons constaté que les refuges climatiques, les gradients de précipitation, les incursions marines et potentiellement les barrières fluviales ont généré une structure phylogéographique pendant le Pléistocène et jusqu'à l'Holocène. Des études examinant la divergence phénotypique et le contact secondaire entre ces populations géographiquement structurées pourraient démontrer comment des barrières biogéographiques à échelle plus petite et plus récentes contribuent à la diversification régionale.

Hidden diversity of rock geckos within the Cnemaspissiamensis species group (Gekkonidae, Squamata): genetic and morphological data from southern Thailand reveal two new insular species and verify the phylogenetic affinities of C.chanardi and C.kamolnorranathi.

Two new insular rock geckos in the genus Cnemaspis are described from Ko Samui in Surat Thani Province and Ko Similan in Phang-nga Province, southern Thailand, based on a combination of morphological and mitochondrial NADH dehydrogenase subunit 2 (ND2) data. Both new species represent divergent lineages within the Cnemaspissiamensis species group. Cnemaspissamui sp. nov. is distinguished from other species in the group by having eight or nine supralabial and infralabial scales; 5-8 pore-bearing precloacal scales in males, pores rounded; 25-27 paravertebral tubercles, arranged randomly; 22-25 subdigital lamellae under 4th toe; enlarged median subcaudal scale row present; gular region, abdomen, limbs and subcaudal region yellowish only in males, and uncorrected pairwise divergences of 8.86-26.83% from all other species in the C.siamensis species group. Cnemaspissimilan sp. nov. is distinguished from other species in the group by having eight or nine supralabial and seven or eight infralabial scales; one pore-bearing precloacal scale in males, pore rounded; 24 or 25 paravertebral tubercles, arranged randomly; 23 or 24 subdigital lamellae under 4th toe; no enlarged median subcaudal scale row; pale yellow reticulum on head, neck, flanks, belly and limbs in male only, and uncorrected pairwise divergences of 9.34-27.11% from all other species in the C.siamensis species group. Cnemaspissamui sp. nov. is found along granitic rocky stream outcrops of Hin Lad Waterfall, Ko Samui, Gulf of Thailand, while Cnemaspissimilan sp. nov. occurs in granitic rocky outcrops near Ao Nguang Chang Bay, Ko Similan, Andaman Sea. The phylogenetic analyses confirmed that C.chanardi and C.kamolnorranathi are also nested within the C.siamensis species group, as previously hypothesized from morphology and color pattern characters.

A new species in the Cyrtodactylusoldhami group (Squamata, Gekkonidae) from Kanchanaburi Province, western Thailand.

Cyrtodactylusmonilatus sp. nov. is described from Si Sawat District, Kanchanaburi Province, in western Thailand. The new species superficially resembles C.zebraicus Taylor, 1962 from southern Thailand. However, differences between the new species from C.zebraicus and other congeners were supported by an integrative taxonomic analysis of molecular and morphological data. Phylogenetic analyses based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene showed that the new species is a member of the C.oldhami group and closely related to Cyrtodactylus sp. MT468911 from Thong Pha Phum National Park, Thong Pha Phum District, Kanchanaburi Province. Uncorrected pairwise genetic divergences (p-distances) between the new species and its congeners, including C.zebraicus, ranged from 7.7-17.7%. Cyrtodactylusmonilatus sp. nov. can also be distinguished from all members of the C.oldhami group by having a unique combination of morphological characters, including a snout to vent length of 53.7-63.3 mm in adult males and 58.6-75.8 mm in adult females; 22-34 paravertebral tubercles; 34-42 ventral scales; 30-39 enlarged contiguous femoroprecloacal scales; femoral pores and precloacal pores absent in both sexes; four or five rows of postprecloacal scales; enlarged median subcaudal scales absent; weak ventrolateral folds present; 4-7 rows of paired, paravertebral, dark-brown blotches edged in yellow or yellowish white; and two rows of small, diffuse, yellow or yellowish white spots on flanks. The new species occurs in a narrow range of forest at mid to low elevations associated with karst landscapes in the Tenasserim mountain range.

A New Limnonectes (Anura: Dicroglossidae) from Southern Thailand.

A new species in the dicroglossid frog genus Limnonectes is described from Ko Pha-ngan, Ko Samui, and Ko Lanta Yai Islands in southern Thailand. Males of Limnonectes pseudodoriae sp. nov. lack a caruncle on top of the head and very closely resemble L. doriae (Boulenger, 1887) from Myanmar and western and southern Thailand. However, the new species is distinguished from L. doriae and its congeners using an integrative taxonomic approach of morphology, mitochondrial DNA, and bioacoustics. Limnonectes pseudodoriae sp. nov. differs from L. doriae and its congeners by having a unique combination of morphological characters, including body size; skin texture of the interorbital region, dorsum, and shank; toe webbing; relative size of the inner metatarsal tubercle; and coloration of the tympanum, venter, and ova. The advertisement call of the new species is also readily differentiated from that of L. doriae in temporal parameters. Limnonectes pseudodoriae sp. nov. is highly divergent in mitochondrial DNA from L. doriae and its congeners, but its phylogenetic position within the genus is not resolved. The natural history of the new species is presented, and the geographic range of L. doriae in Thailand is clarified.

A new fanged frog in the Limnonectes kuhlii complex (Anura: Dicroglossidae) from northeastern Cambodia.

The Limnonectes kuhlii complex is a group of morphologically similar species of fanged frogs distributed across much of mainland and insular Southeast Asia. Many new species in this complex have been described in recent years, primarily on the basis of mitochondrial DNA divergence corroborated by differences in linear measurements and qualitative characters. Males in this species complex develop enlarged heads at sexual maturity, but the degree of head enlargement varies among mature males, even within the same population. We evaluated the utility of body length (snout-vent length minus head length) in descriptive statistics and in size-adjusting measurements for traditional morphometric analysis, as well as a landmark-based geometric morphometric analysis of male head shape, in Indochinese species of the L. kuhlii complex. The analyses supported quantitative and qualitative morphological distinction of a divergent mitochondrial lineage of the L. kuhlii complex in northeastern Cambodia, and the lineage is described as a new species. Limnonectes fastigatus sp. nov. differs from its closest relatives and from geographically proximate members of the complex by having the combination of elongated, slender odontoids; nuptial pads on the first finger; immaculate belly; significantly different body length-adjusted measurements in both sexes; and a significantly different male head shape. The new species is the only member of the L. kuhlii complex known from Cambodia.

A new Leptobrachella (Anura: Megophryidae) from the Cardamom Mountains of Cambodia.

The species-rich, megophryid frog genus Leptobrachella Smith, 1925 is distributed throughout the uplands of mainland Southeast Asia but is conspicuously absent from the Cardamom Mountains of southwestern Cambodia, where it has been known only by a single, undetermined metamorphic specimen collected nearly two decades ago. We report two adult female specimens of Leptobrachella collected a decade later at a second locality in the Cardamom Mountains and use mitochondrial DNA, nuclear DNA, and morphology to show that it represents a distinct species. Leptobrachella neangi sp. nov., named after its collector, is most closely related in mitochondrial and nuclear DNA to L. fuliginosa (Matsui, 2006) and L. melanoleuca (Matsui, 2006) from western Thailand, but has uncorrected pairwise distances of 8.69-10.99% in a mitochondrial 16S gene fragment from its two sister species. The new species is also readily distinguished from these and other congeners by having the combination of (1) SVL 35.4-36.3 mm in two adult females, (2) distinct dorsolateral glandular line absent, (2) belly transparent, immaculate purplish gray in life, creamy white in preservative, (3) dark inguinal blotch absent, (4) tympanum with black coloration extending from line under supratympanic fold, (5) dorsal skin with small, irregular bumps and ridges, and (6) iris coppery orange around pupil, fading to gold at periphery, not distinctly bicolored. The new species is the first named Leptobrachella from the Cardamom Mountains and the third from Cambodia.

A new insular species of the Cyrtodactylus intermedius (Squamata: Gekkonidae) group from Cambodia with a discussion of habitat preference and ecomorphology.

An integrative taxonomic analysis based on mitochondrial and morphological data recovered the population of Cyrtodactylus on Koh Rong Island, Preah Sihanouk Province, Cambodiaa as an endemic insular species belonging to the Cyrtodactylus intermedius group. This brings the number of species in the C. intermedius group to at least 10 and the number of species in Cambodia to at least seven. Species of this relatively small group vary widely in habitat preference, occurring in general, terrestrial, karstic, or granitic habitats. Ancestral character state mapping recovered a general habitat preference as the ancestral condition from which all others independently evolved even though this did not covary with morphology. The description of another new species of reptile from Cambodia continues to underscore the potentially significant amount of unrealized biodiversity in Indochina and Southeast Asia and the continued need for field surveys in unexplored or poorly explored areas.

A new Liopeltis Fitzinger, 1843 (Squamata: Colubridae) from Pulau Tioman, Peninsular Malaysia.

Liopeltis is a genus of poorly known, infrequently sampled species of colubrid snakes in tropical Asia. We collected a specimen of Liopeltis from Pulau Tioman, Peninsular Malaysia, that superficially resembled L. philippina, a rare species that is endemic to the Palawan Pleistocene Aggregate Island Complex, western Philippines. We analyzed morphological and mitochondrial DNA sequence data from the Pulau Tioman specimen and found distinct differences to L. philippina and all other congeners. On the basis of these corroborated lines of evidence, the Pulau Tioman specimen is described as a new species, L. tiomanica sp. nov. The new species occurs in sympatry with L. tricolor on Pulau Tioman, and our description of L. tiomanica sp. nov. brings the number of endemic amphibians and reptiles on Pulau Tioman to 12.

Integrative taxonomy of the rock-dwelling gecko Cnemaspis siamensis complex (Squamata, Gekkonidae) reveals a new species from Nakhon Si Thammarat Province, southern Thailand.

The rock-dwelling gecko genus Cnemaspis is one of the most species-diverse genera of gekkonid in Thailand. Earlier studies relied on morphological data to identify species, but cryptic morphology often obscured species diversity in Cnemaspis. In this study, an integrative taxonomic approach based on morphological characters and sequences of the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene were used to clarify current taxonomy of the Cnemaspis siamensis complex and delimit a new species from Lan Saka District, Nakhon Si Thammarat Province, southern Thailand. Cnemaspis lineatubercularis sp. nov. is distinguished from other congeneric species by the combination of morphological characters: (1) maximum snout-vent length (SVL) of 40.6 mm (mean 38.8 ± SD 1.4, N = 12) in adult males and maximum SVL of 41.8 mm (mean 39.5 ± SD 1.9, N = 7) in adult females; (2) 8-9 supralabial and infralabial scales; (3) gular, pectoral, abdominal, and subcaudal scales keeled; (4) rostral, interorbitals, supercilium, palmar scales, and ventral scales of brachia smooth; (5) 5-6 small, subconical spine-like tubercles present on flanks; (6) 19-21 paravertebral tubercles linearly arranged; (7) 27-29 subdigital lamellae under the fourth toe; (8) 4-7 pore-bearing precloacal scales, pores rounded arranged in chevron shape and separated only in males; (9) one postcloacal tubercles each side in males; (10) ventrolateral caudal tubercles present anteriorly; (11) caudal tubercles restricted to a single paravertebral row on each side; (12) single median row of subcaudal scales keeled and lacking enlarged median row; and (13) gular region, abdomen, limbs and subcaudal region yellowish only in males. Genetically, the uncorrected pairwise divergences between the new species and their congeners in the C. siamensis group were between 15.53-28.09%. The new species is currently known only from granitic rocky streams at Wang Mai Pak Waterfall in the Nakhon Si Thammarat mountain range. Its discovery suggests that additional unrecognized species of Cnemaspis may still occur in unexplored areas of southern Thailand.

A new species of Cyrtodactylus (Squamata, Gekkonidae) from Cambodia's Prey Lang Wildlife Sanctuary.

Cyrtodactylus phnomchiensis sp. nov. is described from Phnom Chi, an isolated mountain in Prey Lang Wildlife Sanctuary, Kampong Thom Province, Cambodia. The new species is recognized by having a unique combination of morphological characters, including snout-vent length 76.1-80.7 mm; paravertebral tubercles 31-36; ventral scales 45-54; enlarged femoral scales 0-8, without pores; enlarged precloacal scales 7-10, bearing pores 4-5 in males, pits 1-7 in females; the posterior border of nuchal loop unbroken and pointed, bordered anteriorly and posteriorly by a broad yellow or yellowish white band; and yellow spots on top of head. The new species also represents a divergent mitochondrial DNA lineage within the C. irregularis complex that is closely related to C. ziegleri, but the phylogenetic relationships among the new species and two divergent mitochondrial subclades within C. ziegleri are not resolved based on available sequence data. Cyrtodactylus phnomchiensis sp. nov. is the only member of the C. irregularis complex known to occur west of the Mekong River. The new species may be endemic to Phnom Chi, and likely faces imminent conservation threats.

A combined approach of mitochondrial DNA and anchored nuclear phylogenomics sheds light on unrecognized diversity, phylogeny, and historical biogeography of the torrent frogs, genus Amolops (Anura: Ranidae).

The genus Amolops ("torrent frogs") is one of the most species-rich genera in Ranidae, with 59 recognized species. This genus currently includes six species groups diagnosed mainly by morphology. Several recent molecular studies indicated that the classification of species groups within Amolops remains controversial, and key nodes in the phylogeny have been inadequately resolved. In addition, the diversity of Amolops remains poorly understood, especially for those from incompletely sampled regions. Herein, we investigate species-level diversity within the genus Amolops throughout southern China and Southeast Asia, and infer evolutionary relationships among the species using mtDNA data (16S, COI, and ND2). Molecular analyses indicate nine unnamed species, mostly distributed in the Himalayas. We then utilized anchored hybrid enrichment to generate a dataset representing the major mitochondrial lineages to resolve phylogenetic relationships, biogeography, and pattern of species diversification. Our resulting phylogeny strongly supports the monophyly of four previously identified species groups (the A. ricketti, A. daiyunensis, A. hainanensis, and A. monticola groups), but paraphyly for the A. mantzorum and A. marmoratus groups, as previously defined. We erect one new species group, the A. viridimaculatus group, and recognize Dubois' (1992) subgenus Amo as the A. larutensis species group. Biogeographic analysis suggests that Amolops originated on the Indo-Burma/Thai-Malay Peninsula at the Eocene/Oligocene boundary, and dispersed outward, exemplifying a common pattern observed for the origin of Asian biodiversity. The early divergence within Amolops coincides with the Himalayan uplift and the lateral extrusion of Indochina at the Oligocene/Miocene boundary. Our results show that paleoclimatic and geomorphological events have profoundly influenced the patterns of lineage diversification within Amolops.

An integrative phylogenomic approach illuminates the evolutionary history of Old World tree frogs (Anura: Rhacophoridae).

Rhacophoridae are one of the most speciose and ecologically diverse families of amphibians. Resolution of their evolutionary relationships is key to understanding the accumulation of biodiversity, yet previous hypotheses based on Sanger sequencing exhibit much discordance amongst generic relationships. This conflict precludes the making of sound macroevolutionary conclusions. Herein, we conduct the first phylogenomic study using broad-scale sampling and sequences of 352 nuclear DNA loci obtained using anchored hybrid enrichment targeted sequencing. The robust time-calibrated phylogenetic hypothesis clarifies several long-disputed relationships and facilitates the testing of evolutionary hypotheses on spatiotemporal diversification and reproductive modes. The major extant lineages of Rhacophoridae appear to have radiated in mainland Asia, and the spatiotemporal process corresponds with several common accumulations of biodiversity in Asia. Analyses do not detect any case of "Out of Himalaya" in Rhacophoridae. All transitions of reproductive modes appear to have evolved in an ordered, gradual sequence associated with gaining independence of standing water for larval development. The different reproductive modes are phylogenetically conserved and the completion of their transitions appear to have occurred over a period of ~30 Ma, which does not fit a pattern of a rapid burst of diversification. Innovations in reproductive modes associate statistically with the uneven distribution of species-richness between clades, where higher diversification is linked to increased terrestrial modes of reproduction. These results strengthen the hypothesis that breeding innovations drive diversification by providing new opportunities for ecological release and dispersion.

Genetic variation and admixture of red-eared sliders (Trachemys scripta elegans) in the USA.

The most ubiquitous, abundant, and invasive turtle on Earth, Trachemys scripta elegans (TSE, "red-eared slider"), is one of four taxa in a clade that is native to the USA and adjacent Mexico (three subspecies of Trachemys scripta plus Trachemys gaigeae). The present range-wide study of this clade is based on 173 known-locality mtDNA sequences combined with ddRAD libraries for 43 samples emphasizing the western part of the range of TSE, its contact with that of T. gaigeae, and anthropogenic hybrids between TSE and T. s. scripta. The data presented here are the first to sample the TSE × T. s. scripta intergrade zone or TSE × T. s. scripta crosses from introduced turtles. In the western part of its range (New Mexico and Texas), most samples of TSE from the Pecos River have mtDNA haplotypes matching T. gaigeae. Structure analysis of SNPs from the ddRAD show evidence of genetic admixture between T. gaigeae and TSE in all included samples from the Rio Grande and Pecos River. These populations also exhibit T. gaigeae-like head stripes, i.e., a postorbital marking that does not reach the eye. The genetic and morphological data are thereby reconciled, as both suggest that these TSE are intergrades. We recommend that these populations continue to be considered TSE, despite the admixture with T. gaigeae. In the Eastern United States, some samples of the morphologically intermediate subspecies T. s. troostii are not genetically distinct from TSE and some samples share morphological characters and genetic affinities with T. s. scripta. Based on these observations we conclude that the taxon T. s. troostii represents intergrades between TSE and T. s. scripta and should not be considered a valid taxon. Near the already established part of the intergrade zone between TSE and T. s. scripta, TSE mtDNA haplotypes have naturally introgressed into typical-looking samples of T. s. scripta in Georgia. Hybrids between introduced TSE and T. s. scripta are also confirmed deeper within the natural range of T. s. scripta in South Carolina and Virginia. Given the examples of feral hybrids deep within its range shown here and elsewhere, the threat of genetic pollution of T. s. scripta by feral TSE is established.

Corrigenda: Species delimitation of crab-eating frogs (Fejervarya cancrivora complex) clarifies taxonomy and geographic distributions in mainland Southeast Asia. ZooKeys 883: 119-153. https://doi.org/10.3897/zookeys.883.37544.

[This corrects the article DOI: 10.3897/zookeys.883.37544.].