We describe a new species of Microhyla from Tram Lap forest, Gia Lai Province, Central Vietnam based on morphological, molecular, and acoustic data. The new species resembles M. butleri morphologically, but differs from all congeners by a combination of the following morphological attributes: (1) medium-sized adult snout–vent length 25.2–27.0 mm in 15 males and 30.5 mm in a single female; (2) body habitus moderately stocky; (3) head flat, snout rounded, slightly prominent in ventral profile; (4) dorsum and flanks slightly shagreened with evenly scattered tiny tubercles, ventral skin smooth; (5) first finger well developed, more than one-half the length of the second finger; (6) tips of three outer fingers slightly enlarged, forming weak disks and tips of all toes distinctly dilated into wide disks with narrow peripheral grooves; (7) finger and toe disks with dorsal median longitudinal grooves; (8) three palmar tubercles and two metatarsal tubercles; (9) tibiotarsal articulation of adpressed limb reaching slightly beyond the orbit; (10) webbing formula: I 1¾–2 II 1½–2¾ III 2–31/3 IV 3¼–1½ V; (11) in life, chin and throat yellowish to bright-orange with tiny dark brown speckling laterally; and (12) a call consisting of 15–26 pulses with a dominant frequency of 1.8–2.2 kHz (recorded at 18.5ºC). We also provide a preliminary genealogy of Microhyla based on analysis of a 2644 bp fragment of 12S–16S rRNA mitochondrial DNA. Based on the examed data, the new species and M. butleri are sister-species (genetic p-distance: 9.0%) and it can be distinguished from M. butleri by its morphology (size, webbing on toes, color) and advertisement call. Interspecific genetic p-distances between the new species and its congeners vary from 9.0% to 14.8%. Microhyla aurantiventris sp. nov. occurs in evergreen montane tropical forests at elevations around 1200 m a.s.l. and is known only from the type locality. The new species appears to be threatened due to intensive logging and agriculture plantation.

Frogs of the genusMicrohylainclude some of the world’s smallest amphibians and represent the largest radiation of Asian microhylids, currently encompassing 50 species, distributed across the Oriental biogeographic region. The genusMicrohylaremains one of the taxonomically most challenging groups of Asian frogs and was found to be paraphyletic with respect to large-sized fossorialGlyphoglossus. In this study we present a time-calibrated phylogeny for frogs in the genusMicrohyla, and discuss taxonomy, historical biogeography, and morphological evolution of these frogs. Our updated phylogeny of the genus with nearly complete taxon sampling includes 48 nominalMicrohylaspecies and several undescribed candidate species. Phylogenetic analyses of 3,207 bp of combined mtDNA and nuDNA data recovered three well-supported groups: theGlyphoglossusclade, Southeast AsianMicrohylaII clade (includesM. annectensspecies group), and a diverseMicrohylaI clade including all other species. Within the largest major clade ofMicrohylaare seven well-supported subclades that we identify as theM. achatina,M. fissipes,M. berdmorei,M. superciliaris,M. ornata,M. butleri, andM. palmipesspecies groups. The phylogenetic position of 12 poorly knownMicrohylaspecies is clarified for the first time. These phylogenetic results, along with molecular clock and ancestral area analyses, show theMicrohyla—Glyphoglossusassemblage to have originated in Southeast Asia in the middle Eocene just after the first hypothesized land connections between the Indian Plate and the Asian mainland. WhileGlyphoglossusandMicrohylaII remained within their ancestral ranges,MicrohylaI expanded its distribution generally east to west, colonizing and diversifying through the Cenozoic. The Indian Subcontinent was colonized by members of fiveMicrohylaspecies groups independently, starting with the end Oligocene—early Miocene that coincides with an onset of seasonally dry climates in South Asia. Body size evolution modeling suggests that four groups ofMicrohylahave independently achieved extreme miniaturization with adult body size below 15 mm. Three of the five smallestMicrohylaspecies are obligate phytotelm-breeders and we argue that their peculiar reproductive biology may be a factor involved in miniaturization. Body size increases inMicrohyla—Glyphoglossusseem to be associated with a burrowing adaptation to seasonally dry habitats. Species delimitation analyses suggest a vast underestimation of species richness and diversity inMicrohylaand reveal 15–33 undescribed species. We revalidateM. nepenthicola, synonymizeM. pulveratawithM. marmorata, and provide insights on taxonomic statuses of a number of poorly known species. Further integrative studies, combining evidence from phylogeny, morphology, advertisement calls, and behavior will result in a better systematic understanding of this morphologically cryptic radiation of Asian frogs.

The Hoang Lien Range in northwest Vietnam is known to harbour five species of Leptobrachella, a specious genus of terrestrial frogs. We collected specimens of Leptobrachella from Mount Pu Ta Leng on the second highest peak in the Hoang Lien Range and use morphological and molecular data to show that this population represents a previously undescribed species which we name Leptobrachella graminicola sp. nov. after the abundance of calling males on sedge-like plants. This new species is closely related to L. bourreti but the new species is distinguished from L. bourreti and other congeneric species by a combination of the following characters: (1) a body size range of 23.1–24.6 mm in six adult males and 28.6–32.9 mm in five adult females; (2) skin on dorsum smooth, with many tubercles and lacking dermal ridges; (3) toes with rudimentary webbing and broad lateral fringes; (4) belly white with brown spots; (5) throat dark brown with light grey-brown flecks and spots; (6) a row of large white spots on the outer edge of the tarsus extending from the heel to the inner metatarsal tubercle, sometimes forming a long white stripe; and (7) a bicoloured iris. The new, high-elevation species is likely to be range-restricted and threatened by habitat loss and the activities of tourists.

The genus Megophrys is known to harbour morphological cryptic species diversity. During field work on Vietnam’s third highest peak, Mount Ky Quan San, north-west Vietnam, we collected specimens of a new species of Megophrys at two locations more than 2000 m above sea level (asl). Phylogenetic analyses using mitochondrial markers place the new species within the subgenus Panophrys, a primarily Chinese radiation within the genus Megophrys. We describe the species based on an all-male type series and distinguish it from all other Megophrys species from mainland Southeast Asia, north of the Isthmus of Kra and nearby provinces of China (Yunnan, Guangxi and Guizhou) based on morphological, molecular and bioacoustic data. The new species is inferred to form a clade along with M. hoanglienensis and M. fansipanensis; it is syntopic with the former but has a non-overlapping range with the latter. Uncorrected p distances for the 16S rDNA and CO1 genes between the new species and closest relatives exceed values observed between other closely related species in the Panophrys subgenus. The new species is most similar to M. fansipanensis in terms of morphology, and several call parameters also overlap with this species; however, these two species call at different times of year. This is the fourth likely range-restricted and Endangered Megophrys species described from the Hoang Lien Range since 2017, and this discovery further highlights the significance of the Hoang Lien Range for Vietnam’s amphibian diversity. http://zoobank.org/NomenclaturalActs/69340DD7-B21E-4DD0-836F-6741878013BB

Morphological, acoustic and molecular analyses result in the description of Leptolalax rowleyae sp. nov., a new species of frog in the Megophryidae, belonging to the L. applebyi Rowley & Cao species group from central Vietnam. It differs from its congeners by a combination of the following morphological attributes: (1) adult SVL 23.4–25.4 mm in males and 27–27.8 mm in females; (2) presence of distinct dark/brown dorsolateral markings, including black spots on flanks; (3) pinkish milk-white to light brown chest and belly with numerous white speckles; (4) tympanum distinct; (5) absence of webbing or lateral dermal fringes on fingers and toes; (6) pectoral glands comparatively small (3.3–4.7% of SVL); (7) ventrolateral glands indistinct; and (8) iris bicolored with copper tint in upper half fading to golden in lower third of iris. The male advertisement call of the new species consists of 4–6 notes, lacking a distinct introductory note, with an average dominant frequency of 3.2–3.5 kHz. The description of the tadpole constitutes the first description of larval morphology for a member of the L. appleybi species group. Genetically, an uncorrected sequence divergence of 7.4% for 16S rRNA separates the new species from its two closest relatives, L. ardens and L. melicus in the L. applebyi species group.

Species of bent-toed gecko (Cyrtodactylus) in Vietnam have been described at a rate of nearly four species per year since 2007 mostly based on morphological data. A tool that guides species delimitation will accelerate the rate of documentation, and at a time when the recognition of species greatly benefits conservation. We use DNA barcoding using COI (550 bp) to re-examine the levels of genetic divergence and taxonomic status of 21 described species of Vietnamese bent-toed geckos. Tree-based analyses resolve all sampled species and identify potential undescribed taxa. Kimura 2-parameter genetic distances between the described species average 21.0±4.2% and range from 4.3% to 28.7%. Further, our analyses discover two potentially new species from Vietnam, two from Laos and one from China. Herein we describe the new species Cyrtodactylus puhuensis sp. nov. from Vietnam on the basis of both genetics and morphology. Genetically, it differs from the remaining species by an average K2P distance of 24.0±1.8%. Morphologically, the new species is diagnosed by its medium-size (snout-vent length 79.24 mm and tail length 82.59 mm, for the single known individual), in having a series of moderately enlarged transverse subcaudals and a series of moderately enlarged femoral scales that extend from precloacal scales, in possessing femoral scales without pores, with males having five precloacal pores, and in exhibiting 8 supralabials, 10 infralabials, 23 narrow subdigital lamellae on its fourth toe, and 36 transverse ventrals.