Two new Leptobrachella species (Anura, Megophryidae) from the Yunnan-Guizhou Plateau, southwestern China

Abstract Two new toad species of the genus Leptobrachella are described from the Yunnan-Guizhou Plateau of China, based on the combination of molecular and morphological data. The description of Leptobrachella aspera Wang, Lyu, Qi & Wang, sp. nov. from Huanglianshan Nature Reserve represents the thirteenth Leptobrachella species known from Yunnan Province, and the description of Leptobrachella dorsospina Wang, Lyu, Qi & Wang, sp. nov. from Yushe Forest Park represents the sixth Leptobrachella species known from Guizhou Province. These new discoveries further emphasize the extremely high diversity of the Leptobrachella toads in these regions.


introduction
The generic classifications within the family Megophryidae Bonaparte, 1850 have always been controversial. For example, recent comprehensive approaches have produced different taxonomic schemes for the genus Megophrys sensu lato Kuhl and Van Hasselt 1822 Mahony et al. 2017;Liu et al. 2018;Li et al. 2020b). The taxonomy of another group of megophrid toads are facing the same problem: Chen et al. (2018) presented the first well-resolved phylogenetic hypothesis for the genera Leptolalax Dubois, 1983 and Leptobrachella Bonaparte, 1850. They tended towards the most conservative "one-genus option" pending the acquisition of additional data by assigning Leptolalax as a junior synonym of Leptobrachella. Their results also rejected the hypothesis that Leptolalax consists of two subgenera as proposed by Delorme et al. (2006) and Dubois et al. (2010). In this context, the genus Leptobrachella currently contains 82 species widely distributed from southern China, west to northeastern India, through Indochina to the island of Borneo (Frost 2020). Leptobrachella is a species-rich genus of megophrid frogs, and a large number of new species have been discovered in recent years due to the application of integrative taxonomy incorporating detailed morphological, bioacoustic and molecular analyses Yang et al. 2016;Yuan et al. 2017;Eto et al. 2018;Nguyen et al. 2018;Wang et al. 2019;Chen et al. 2020;Luo et al. 2020;Qian et al. 2020).
During recent field surveys in the Yunnan-Guizhou Plateau of southwestern China, a number of megophrid specimens were collected from Yushe Forest Park in western Guizhou (Fig. 1, site 1) and Huanglianshan Nature Reserve in southern Yunnan ( Fig. 1, site 2), respectively. Morphologically, all the specimens can be assigned to the genus "Leptolalax" (now a junior subjective synonym of Leptobrachella), based on the following characters: (1) small or moderate size, snout-vent length not greater than 60.0 mm, (2) rounded finger tips, the presence of an elevated inner palmar tubercle not continuous to the thumb, (3) presence of macroglands on body including supra-axillary, pectoral, femoral and ventrolateral glands, (4) vomerine teeth absent, (5) tubercles on eyelids present, and (6) anterior tip of snout with whitish vertical bar (Dubois 1983;Matsui 1997Lathrop et al. 1998;Delorme et al. 2006;Das et al. 2010). Although their generic allocation is without doubt, some characters of these specimens do not correspond to the diagnoses of any recognized species. Subsequent molecular analysis further revealed that these specimens represent two distinct evolutionary lineages. Considering both the morphological differences and molecular divergences, these specimens are described herein as two new species.

Sampling
For the molecular analyses, a total of 80 sequences (nine muscle tissue samples was sequenced and 71 sequences obtained from GenBank) were used, including five sequences of the undescribed species from Guizhou, four sequences of the undescribed species from Yunnan, 69 sequences of 66 recognized congeners, and two out-group sequences of Oreolalax rhodostigmatus Hu & Fei, 1979 and Leptobrachium tengchongensis Yang & Huang, 2019, respectively (Table 1). Due to the presence of cryptic diversity within genus Leptobrachella, we chose sequences from type series or topotype specimens for molecular analysis if available to ensure the taxonomic identity of the species being studied.
DNA Extraction, PCR, and sequencing DNA was extracted from muscle tissue using a DNA extraction kit from Tiangen Biotech (Beijing) Co., Ltd. The mitochondrial gene 16S ribosomal RNA gene (16S rRNA) fragment from each sample was sequenced. Fragments were amplified using the primer Figure 1. Collection sites. Site 1-Yushe Forest Park, Shuicheng County, Guizhou Province, the type locality of Leptobrachella dorsospina sp. nov.; site 2-Huanglianshan Nature Reserve, Lyuchun County, Yunnan Province, the type locality of L. aspera sp. nov.; site 3-Xiaoqiaogou Nature Reserve, Xichou County, Yunnan Province, the type locality of L. feii; and site 4-Daweishan Nature Reserve, Pingbian County, Yunnan Province, another distribution locality of L. feii. pairs L3975 (5'-CGCCTGTTTACCAAAAACAT-3') and H4551 (5'-CCGGTCT-GAACTCAGATCACGT-3') (Simon et al. 1994). PCR amplifications were performed in a 20 μl reaction volume with the following cycling conditions: an initial denaturing step at 95 °C for five min; 35 cycles of denaturing at 95 °C for 40 s, annealing at 53 °C for 40 s and extending at 72 °C for one min; and a final extending step of 72 °C for 10 min. PCR products were purified with spin columns. The purified products were sequenced with both forward and reverse primers using BigDye Terminator Cycle Sequencing Kit according to the guidelines of the manufacturer. The products were sequenced on an ABI Prism 3730 automated DNA sequencer in Shanghai Majorbio Biopharm Technology Co., Ltd. All sequences have been deposited in GenBank (Table 1).

Phylogenetic analyses
Sequences were aligned in Clustal X 2.0 (Thompson et al. 1997) with default parameters. For GenBank sequences which lack information for part of the missing segments, we filled the blank sites with "N". The aligned data was trimmed allowing no gap positions and default parameters in Gblocks version 0.91b (Castresana 2000). lyWe ran Jmodeltest v2.1.2 (Darriba et al. 2012) with Akaike and Bayesian information criteria on the alignment and obtained the best-fitting nucleotide substitution model of GTR + I + G. Phylogenetic analysis was using Bayesian inference (BI) in MrBayes 3.2.4 (Ronquist et al. 2012). Two independent runs with four Markov Chain Monte Carlo simulations were performed for ten million iterations and sampled every 1000 iterations. The first 25% of samples were discarded as burn-in. Convergence of the Markov Chain Monte Carlo simulations was assessed by PSRF ≤ 0.01 and ESS (effective sample size) value > 200 using Tracer 1.4 (http://tree.bio.ed.ac.uk/software/tracer/). Genetic distances among all Leptobrachella samples were calculated in MEGA 6 using the uncorrected p-distance model, with pairwise deletion of gaps and missing data.

Morphometrics
Measurements followed Fei et al. (2009) and Rowley et al. (2013), and were taken with a digital caliper to the nearest 0.1 mm. These measurements were as follows: SVL snout-vent length (from tip of snout to vent); HDL head length (from tip of snout to rear of jaws); HDW head width (head width at commissure of jaws); SNT snout length (from tip of snout to anterior corner of eye); EYE eye diameter (diameter of exposed portion of eyeball); IOD interorbital distance (minimum distance between upper eyelids); IND internasal distance (distance between nares); TMP tympanum diameter (horizontal diameter of tympanum); TEY tympanum-eye distance (distance from anterior edge of tympanum to posterior corner of eye); TIB tibia length (distance from knee to heel); ML manus length (distance from tip of third digit to proximal edge of inner palmar tubercle); PL pes length (distance from tip of fourth toe to proximal edge of the inner metatarsal tubercle); LAHL length of lower arm and hand (distance from tip of the third finger to elbow); HLL hindlimb length (distance from tip of fourth toe to vent).
Sex was determined by the presence of internal vocal sac openings, and the presence of eggs in abdomen seen via external inspection.
All specimens were fixed in 10% buffered formalin and later transferred to 70% ethanol for preservation, and deposited at the Museum of Biology, Sun Yat-sen University (SYS) and Chengdu Institute of Biology, the Chinese Academy of Sciences (CIB), China; tissue samples were preserved in 95% ethanol for molecular studies.
Comparative morphological data of Leptobrachella species were obtained from examination of museum specimens (see Appendix 1) and from the references listed in Table 2. Due to the high likelihood of undiagnosed diversity within the genus Yang et al. 2016), where available, we rely on examination of topotypic material and/or original species descriptions.

results
The BI analyses are shown in Fig. 2 with Bayesian posterior probabilities (BPP) for major nodes > 0.90. Genetic distances among all Leptobrachella samples are given in the Suppl. material 1: Table S1. Comparative morphological data of all recognized Leptobrachella species occurring north of the Kra Isthmus are listed in Table 3.

ID
Leptobrachella species Literature 1 L. aerea (Rowley, Stuart, Richards, Phimmachak & Sivongxay, 2010) Rowley et al. 2010c As shown by the phylogenetic result, Leptobrachella samples from Huanglianshan Nature Reserve are clustered in a distinct and robust monophyletic lineage with strong support (BPP 1.00). This lineage forms the sister taxon to L. feii occurring in Xiaoqiaogou Nature Reserve (BPP 1.00). The genetic distances between these two lineages are 3.0-3.4%, which is significantly larger than that among other recognized species (e.g., p-distance 2.6% between L. liui and L. mangshanensis). Detailed morphological examination also reveals a combination of characters that distinguish the specimens of the unnamed lineage from L. feii and other known congeners (see taxonomic comparison below). Therefore, based on the molecular and morphological differences, the population from Huanglianshan Nature Reserve is proposed as a new species, Leptobrachella aspera sp. nov.
Samples of the other unnamed lineage from Yushe Forest Park, cluster in another distinct and robust monophyletic lineage with strong support (BPP 1.00). This lineage is close to several species occurring in southwestern China, but its specific placement remains unresolved due to the insufficient support values. The smallest genetic distance between this lineage and another congener is 3.5% (vs. L. purpuraventra), which is significantly larger than that between other recognized species (e.g., p-distance 2.6% between L. liui and L. mangshanensis). Detailed morphological examination also reveals a combination of characteristics distinguishing the specimens of this lineage from all known congeners (see taxonomic comparison below). Therefore, based on the molecular and morphological differences, the population from Yushe Forest Park is proposed as a new species, Leptobrachella dorsospina sp. nov.  and glandular folds, (3) iris bicolored, amber on upper half and silver on lower half, (4) tympanum distinctly discernible, distinct black supratympanic line present, (5) absence of webbing and lateral fringes on fingers, toes with rudimentary webbing and narrow lateral fringes both in males and females, (6) longitudinal ridges under toes not interrupted at the articulations, (7) relative finger lengths I < IV < II < III, relative toe length I < II < V < III < IV, (8) heels just meeting, tibia-tarsal articulation reaches the region between middle of eye to anterior corner of eye, (9) dorsum greyish brown to yellowish brown grounding, with small light orange granules and distinct darker brown markings scattered with irregular light orange or greyish white pigmentations, (10) flanks with several enlarged dark patches with light yellowish green margin, (11) ventral surface creamy white, with distinct regular dark patches on chest and abdomen. Comparison. From the 26 known congeners of the genus Leptobrachella occurring south of the Kra Isthmus, the presence of supra-axillary and ventrolateral glands, can easily distinguish L. aspera sp. nov. from L. arayai, L. dringi, L. fritinniens, L. gracilis, L. hamidi, L. heteropus, L. kajangensis, L. kecil, L. marmorata, L. melanoleuca, L. maura, L. picta, L. platycephala, L. sabahmontana  Leptobrachella aspera sp. nov. is recovered as a sister taxon to L. feii in the phylogenetic tree (Fig. 2). However, the new species can be distinguished from L. feii by the following morphological characters: head relatively short, HDL/SVL 0.33-0.35 (vs. head relatively long, HDL/SVL 0.38-0.43); distinct regular dark patches on skin of chest and abdomen (vs. irregular black blotches scattered on skin of chest and belly); color of upper half of iris amber (vs. color of upper half of iris lighter, golden orange); ventrolateral glands forming an non-continuous line (vs. ventrolateral glands forming a continuous line); relative finger lengths I < IV < II < III (vs. relative finger lengths II < I < IV < III); tibio-tarsal articulation of adpressed limb reaching the region between middle of eye to anterior corner of eye (vs. tibio-tarsal articulation of adpressed limb reaching beyond eye).
While Leptobrachella pluvialis is distributed in the same mountain range on the Vietnamese side and possesses similar body size , it can be separated from L. aspera sp. nov. by the following characters: (1) smooth dorsal skin with flattened tubercles on flanks (vs. rough dorsal skin with dense conical granules in L. aspera sp. nov.), (2) absence of webbing on toes (vs. rudimentary webbing on toes in L. aspera sp. nov.), and (3) relatively longer hindlimbs, the tibia-tarsal articulation reaching to the nostril (vs. relatively shorter hindlimbs, the tibia-tarsal articulation reaching the region between middle of eye to anterior corner of eye in L. aspera sp. nov.).
For crocea, and L. melica, all having no lateral fringes on toes, and from L. liui, having wide lateral fringes on toes; by the creamy white ventral coloration and distinct regular dark patches on the chest and abdomen, the new species can be distinguished from L. applebyi, L. ardens, L. bidoupensis, and L. melica, all having reddish brown ventral coloration with white specks, from L. crocea, having bright orange ventral coloration, from L. mangshanensis, lacking dark skin patches on the chest and abdomen, from L. liui, having creamy white ventral coloration with dark brown spots on the chest and margins, and from L. niveimontis, having marbling ventral coloration with black speckling; by rough dorsal skin with dense conical granules, tubercles and glandular folds, the new species can be distinguished from L. applebyi, L. ardens, L. bidoupensis, L. mangshanensis, L. melica, and L. niveimontis, all having smooth dorsal skin.
Description of holotype. Adult male. Body size small, SVL 22.4 mm. Head length slightly larger than head width, HDW/HDL 0.99; snout slightly protruding, projecting slightly beyond margin of the lower jaw; nostril closer to snout than eye; canthus rostralis gently rounded; loreal region slightly concave; interorbital space flat, internarial distance greater than interorbital distance, IND/IOD 1.07; pineal ocellus absent; pupil vertical; snout length longer than eye diameter, SNT/EYE 1.26; tympanum distinct, rounded, and slightly concave, diameter smaller than that of the eye and larger than tympanum-eye distance, TMP/EYE 0.52 and TEY/TMP 0.44; upper margin of tympanum in contact with supratympanic ridge; distinct black supratympanic line present; vomerine teeth absent; vocal sac openings slit-like, paired, located posterolaterally on floor of mouth in close proximity to the margins of the mandible; tongue deeply notched posteriorly; supratympanic ridge distinct, extending from posterior corner of eye to supra-axillary gland.
Tips of fingers rounded, slightly swollen; relative finger lengths I < IV < II < III; nuptial pad absent; subarticular tubercles absent; large, rounded inner palmar tubercle distinctly separated from small, rounded outer palmar tubercle; webbing and lateral fringes on fingers absent. Tips of toes rounded, slightly swollen; relative toe length I < II < V < III < IV; subarticular tubercles absent; distinct longitudinal dermal ridges present under the 3 rd to 5 th toes, not interrupted; large, oval inner metatarsal tubercle present, outer metatarsal tubercle absent; toes webbing rudimentary; narrow lateral fringes present on all toes. Tibia 47% of snout-vent length; tibiotarsal articulation reaching to anterior corner of eye; heels slightly overlapping when thighs are appressed at right angles with respect to body.
Dorsal skin rough, with dense conical granules, tubercles and glandular folds; ventral skin smooth; sparse tiny tubercles present on surface of chest; pectoral gland and femoral gland oval; the size of pectoral glands almost equal to tips of fingers and femoral glands; femoral gland situated on posteroventral surface of thigh, closer to knee than to vent; supra-axillary glands raised. Ventrolateral glands distinctly visible, raised, forming an incomplete line.
Coloration of holotype in life. Dorsum greyish brown with small light orange granules, distinct darker brown markings scattered with irregular light orange and greyish white pigmentations. A dark brown inverted triangular pattern between the anterior corners of the eyes in connection with a dark brown W-shaped marking in the interorbital region, which is also connected to a W-shaped marking between the axillae. Tympanum dark brown. Small light orange granules present on dorsum of body and limbs; a dark brown blotch under the eye; transverse dark brown bars present on dorsal surface of limbs and digits; distinct dark brown patches with light yellowish green margin on flanks from groin to axilla; elbow and upper arms with distinct coppery orange coloration.
Ventral surface of throat, chest, and belly creamy white; presence of distinct nebulous greyish speckles present on throat, and distinct dark patches on chest and abdomen; ventral surface of limbs greyish purple, scattered with greyish white spots and small patches. Supra-axillary gland coppery orange; femoral, pectoral, and ventrolateral glands greyish white. Iris bicolored, amber on upper half and silver on lower half.
Coloration of holotype in preservative (Fig. 4A). Dorsum of body and limbs dark brown; transverse bars on limbs become more distinct; dark brown patterns, markings and spots on the back become indistinct, orange pigmentations become dark brown, greyish white pigmentations become dark grey. Ventral surface of limbs and surface of throat light brown, surface of abdomen greyish white, nebulous speckles on throat absent, dark patches on chest, abdomen and flanks become more distinct, light yellowish green margin of patches on flanks absent. Supra-axillary, femoral, pectoral, and ventrolateral glands greyish white.
Variation. Measurements and body proportions are listed in Table 4. Nonsexual characters of all the female paratypes (SYS a007744, 7745, 7746) match the overall characters of the holotype except that: the dorsum is greyish brown in the holotype SYS a007743 (vs. yellowish brown in the paratypes); the size of the pectoral glands are almost equal to the tips of the fingers and the femoral glands (vs. the size of the pectoral glands are larger than the tips of fingers and the femoral glands in the paratypes); the tibia-tarsal articulation reaches forward to the anterior corner of the eye in the holotype (vs. the tibia-tarsal articulation reaches forward to the middle of the eye in the paratypes SYS a007745, 7746); the ventral skin of the thighs smooth (vs. the ventral skin of the thighs rough with dense raised tubercles in the paratypes).  Etymology. The specific epithet, aspera, is a Latin adjective which means rough, in reference to the dorsal skin texture of the new species. According to its type locality, we suggest its English common name as "Huanglianshan Leaf Litter Toad", and the Chinese name "Huang Lian Shan Zhang Tu Chan (黄连山掌突蟾)".
Distribution and habits. Currently, Leptobrachella aspera sp. nov. is known only from its type locality Huanglianshan Nature Reserve, near the border between China and Vietnam. The new species was found along a drainage ditch of a mountainous road. The road was surrounded by broad-leaved forest at an altitude ca. 1930 m and not close to any hillstreams. Males were not heard calling during the field survey from 31 May to 1 June 2019. Paratypes (N = 6). An adult male, SYS a004977, and five adult females, SYS a004961/CIB116081, SYS a 004962, SYS a004973, 4975, 4976, collected by Zhi-Tong Lyu and Run-Lin Li on 20-21 June 2016 from the same locality as the holotype. Diagnosis.
(1) Small size (SVL 28.7-30.5 mm in two adult males, 32.1-39.8 mm in five adult females), (2) dorsal skin rough, with dense conical granules, tubercles, glandular folds and conical spines, (3) iris bicolored, light orange on upper half and silver on lower half, (4) tympanum distinctly discernible, distinct black supratympanic line present, (5) absence of webbing and lateral fringes on fingers, toes with rudimentary webbing and narrow lateral fringes both in males and females, (6) longitudinal ridges under toes interrupted at the articulations, (7) relative finger lengths II = IV < I < III, relative toe length I < II < V < III < IV, (8) heels slightly overlapping, tibia-tarsal articulation reaches forward to the posterior corners of eyes, (9) dorsum greyish brown to dark brown grounding, with distinct darker brown markings and scattered with irregular light greyish brown pigmentations and yellowish brown spots, (10) flanks with several enlarged dark patches positioned longitudinally in two rows, (11) ventral surface greyish white with black spots and orange pigmentations.  lack black spots on the flanks. By having rough dorsal skin with conical spines, the new species can be distinguished from L. bijie, L. chishuiensis, L. liui, L. maoershanensis, L. pyrrhops, L. purpuraventra, L. suiyangensis, L. wuhuangmontis, L. wulingensis, and L. yunkaiensis (dorsal skin lacking spines); and from L. bourreti, L. fuliginosa, L. kalonensis, L. minima, L. oshanensis, and L. pelodytoides (dorsal skin smooth). By having narrow lateral fringes on the toes, the new species can be distinguished from L. lateralis, L. macrops, L. nyx, L. pyrrhops, L. namdongensis and L. neangi, all of which lack lateral fringes on the toes. The new species can be separated from the remaining L. nokrekensis by having greyish white ventral coloration with black patches and orange pigmentations (vs. creamy white), and having dense short glandular folds on the dorsal surface (vs. only a few glandular folds on the dorsal surface).
Description of holotype. Adult male. Body size rather small, SVL 30.5 mm. Head length slightly larger than head width, HDW/HDL 0.99; snout slightly protruding, projecting slightly beyond margin of the lower jaw; nostril closer to snout than eye; canthus rostralis gently rounded; loreal region slightly concave; interorbital space flat, internarial distance smaller than interorbital distance, IND/IOD 0.91; pineal ocellus absent; vertical pupil; snout length larger than eye diameter, SNT/EYE 1.29; tympanum distinct, rounded, and slightly concave, diameter smaller than that of the eye and larger than tympanum-eye distance, TMP/EYE 0.43 and TEY/TMP 0.50; upper margin of tympanum in contact with supratympanic ridge; distinct black supratympanic line present; vomerine teeth absent; vocal sac openings slit-like, paired, located posterolaterally on floor of mouth in close proximity to the margins of the mandible; tongue deeply notched posteriorly; supratympanic ridge distinct, extending from posterior corner of eye to supra-axillary gland.
Tips of fingers rounded, slightly swollen; relative finger lengths II = IV < I < III; nuptial pad absent; subarticular tubercles absent; large, rounded inner palmar tubercle distinctly separated from small, rounded outer palmar tubercle; absence of webbing and lateral fringes on fingers. Tips of toes rounded, slightly swollen; relative toe length I < II < V < III < IV; subarticular tubercles absent; distinct longitudinal dermal ridges present under the 3 rd to 5 th toes, interrupted; large, oval inner metatarsal tubercle present, outer metatarsal tubercle absent; toes webbing rudimentary; narrow lateral fringes present on all toes. Tibia 44% of snout-vent length; tibiotarsal articulation reaches to posterior corner of eye; heels slightly overlapping when thighs are appressed at right angles with respect to body.
Dorsal skin rough, with dense conical granules, tubercles, glandular folds and conical spines; ventral skin smooth; pectoral gland and femoral gland oval; the size of pectoral glands almost equal to tips of fingers and femoral glands; femoral gland situated on posteroventral surface of thigh, closer to knee than to vent; supra-axillary glands raised. Ventrolateral glands distinctly visible, raised, forming an incomplete line.
Coloration of holotype in life. Dorsum greyish brown with distinct darker brown markings on sides and scattered with irregular light greyish brown pigmentations and yellowish brown spots. An indistinct, darker brown inverted triangular pattern between anterior corners of the eyes, connected to an indistinct dark brown W-shaped marking between the axillae. Dense translucent spines present on dorsal skin of body and limbs. Upper 2/3 of the tympanum dark brown, lower 1/3 light orange, scattered with tiny coppery orange spots. Small greyish white and light brown granules present on the dorsum of the body and limbs; a dark brown vertical bar under the eye; transverse dark brown bars on the dorsal surface of the limbs and digits; distinct dark brown patches on the flanks, from groin to axilla; elbow and upper arms with distinct light orange coloration.
Ventral surface of throat, chest, and belly greyish white; throat with light brown speckles, chest, and abdomen with distinct dark patches; ventral surface of limbs dark grey, scattered with greyish white spots and small patches. Supra-axillary gland light orange; femoral, pectoral, and ventrolateral glands greyish white. Iris bicolored, light orange on upper half and silver on lower half.
Coloration of holotype in preservative (Fig. 4B). Dorsum of body and limbs dark brown; transverse bars on limbs, dark brown patterns, markings, and spots on back become indistinct, light greyish brown pigmentations and yellowish spots absent. Translucent spines on dorsal skin of body and limbs become grey. Ventral surface of limbs and surface of throat light brown, surface of abdomen greyish white, dark patches on chest, abdomen and flanks become more distinct. Supra-axillary, femoral, pectoral, and ventrolateral glands greyish white.
Variations. Measurements and body proportions are listed in Table 5. All the female paratypes match the overall characters of the holotype except that: the dorsum is greyish brown in the holotype SYS a004974 (vs. dark brown in the paratypes SYS a004961, 4962), and black spots on the ventral skin are more dense and distinct in the paratypes SYS a004961, 4962. Etymology. The specific epithet, dorsospina, is in reference to the conical spines on the dorsal surface of body in the new species. According to its type locality, we suggest its English common name as "Shuicheng Leaf Litter Toad", and the Chinese name "Shui Cheng Zhang Tu Chan (水城掌突蟾)".
Distribution and habits. Currently, Leptobrachella dorsospina sp. nov. is known only from its type locality, Yushe Forest Park, which is near the border between Guizhou and Yunnan. The new species was found on the surface of fallen leaves by the clear-water rocky hill-stream in well-preserved montane evergreen broadleaf forest (ca. 2100 m a.s.l.). Males were not heard calling.

Discussion
In the phylogenetic tree, the Leptobrachella pelodytoides (voucher number: MVZ 223642) sample from Tam Dao, northern Vietnam is clustered together with the topotypic L. ventripunctata (voucher number: SYS a001768) sample from Xishuangbanna, Yunnan, China, with a genetic divergence of only 1.5% (Fig. 2, Suppl. material 1: Table S1), which is of a intraspecific level. In addition, the type locality of L. pelodytoides is Thao [= Thamo], Kayah State, Myanmar, which is geographically distant from northern Vietnam with a distance over 900 km. Considering the above, we recommend that the specimen MVZ 223642 be reappraised as L. ventripunctata.
Yunnan and Guizhou are both largely within the species-rich Dian freshwater zoogeographical dominion (Huang et al 2020). Spanning the Indo-Burma Hotspot and the Mountains of Southwest China Hotspot (Tordoff et al. 2012), Yunnan Province has for long been considered as one of the most biodiverse regions in China and its flora and fauna have attracted much attention. However, Guizhou Province, which also shares the Yunnan-Guizhou Plateau, remains relatively neglected; knowledge of biodiversity levels and patterns are seriously lacking. In recent years, large numbers of discoveries have been made from Guizhou, dramatically raising the number of frog species known from the region Li et al. 2018aLi et al. , b, 2019aLi et al. , b, 2020aLyu et al. 2019;Wang et al. 2019;Luo et al. 2020;Wei et al. 2020). Further comprehensive surveys are urgently needed to determine the true diversity of the amphibians of Guizhou Province.