A new species of Leptolalax (Anura: Megophryidae) from northern Vietnam Author Rowley, Jodi J. L. Author Dau, Vinh Q. Author Hoang, Huy D. Author Le, Duong T. T. Author Cutajar, Timothy P. Author Nguyen, Tao T. text Zootaxa 2017 4243 3 544 564 journal article 36262 10.11646/zootaxa.4243.3.7 c4b4ea62-a272-4a2f-8919-18236a06e3f5 1175-5326 400196 DF89AEF5-CBAB-42A1-84A4-66B1BDD505D6 Leptolalax petrops sp. nov. Figs. 3–4 . Holotype : VNMN 2016 A.06, adult male, 0.5 m from 5 m wide, rocky stream in evergreen forest at Cham Chu Nature Reserve, Tuyen Quang Province , Vietnam ( 22.2045 ° N , 105.0754 ° E , 715 m ; Fig. 1 ). Collected on 25 May 2013 by Jodi J. L. Rowley, Dau Quang Vinh, Hoang Duc Huy, and Hoang Anh Tuan. Paratypes : AMS R 84828, adult female, and AMS R184828, VNMN 2016 A.08, VNMN 2016 A.09, VNMN 2016 A.10, VNMN 2016 A.11, AMS R184829, six adult males, collected at same location and date as holotype ; AMS R184826 and AMS R1848287, two adult males, collected at same location as holotype on 24 May 2013 . AMS R184830, AMS R184832, AMS R184833, three adult males collected at same location as holotype on 26 May 2013 . AMS R184831, adult male, collected 2 m from 5 m wide rocky stream in evergreen forest at Cham Chu Nature Reserve , Tuyen Quang Province , Vietnam ( 22.2061 ° N , 105.0747 ° E , 587 m ) on 26 May 2013 . AMS R184834, adult male collected 0.5 m from 15 m wide, rocky stream in disturbed evergreen forest at Cham Chu Nature Reserve , Tuyen Quang Province , Vietnam ( 22.2105 ° N , 105.0619 ° E , 234 m ) on 1 June 2013 . VNMN 2016 A.12, adult female collected near 1–2 m wide creek in evergreen forest at Cham Chu Nature Reserve , Tuyen Quang Province , Vietnam ( 22.2118 ° N , 105.0824 ° E , 996 m ) on 27 May 2013 . VNMN 2016 A.13, AMS R184836, two adult females, and AMS R184835, adult male, collected in disturbed evergreen forest at Cham Chu Nature Reserve , Tuyen Quang Province , Vietnam ( 22.2067 ° N , 105.0783 ° E , 679 m ) on 28 May 2013 . AMS R184837, adult female, and AMS R184838, AMS R184839, AMS R184841, three adult males, collected in evergreen forest near 5–6 m wide rocky stream at Cham Chu Nature Reserve , Tuyen Quang Province , Vietnam ( 22.2062 N , 105.0811 E , 814 m ) on 29 May 2013 . AMS R184840, adult male, collected in evergreen forest at Cham Chu Nature Reserve , Tuyen Quang Province , Vietnam ( 22.2054 ° N , 105.0824 ° E , 835 m ) on 29 May 2013 . All specimens were collected by Jodi J. L. Rowley, Dau Quang Vinh , Hoang Duc Huy , and Hoang Anh Tuan . AMS R184842, AMS R184843, AMS R184845, three adult females, and AMS R184844, one adult male, collected in Pe Xa Forest , Sin Ho District , Lai Chau Province , Vietnam ( 22.2758 ° N , 103.2637 ° E , 1257 m ) on 14 September 2013 . VNMN 2016 A.14, adult male, and VNMN 2016 A.15, VNMN 2016 A.16, two adult females, collected in Pe Xa Forest , Sin Ho District , Lai Chau Province , Vietnam ( 22.2758 ° N , 103.2637 ° E , 1257 m ) on 15 September 2013 . VNMN 2016 A.17, VNMN 2016 A.18, VNMN 2016 A.19, three adult females, collected in Pe Xa Forest , Sin Ho District , Lai Chau Province , Vietnam ( 22.2758 ° N , 103.2637 ° E , 1257 m ) on 18 September 2013 . VNMN 2016 A.20, one adult female, collected in Pe Xa Forest , Sin Ho District , Lai Chau Province , Vietnam ( 22.2740 ° N , 103.2648 ° E , 1237 m ) on 17 September 2013 . AMS R184846, one adult female, collected in Pe Xa Forest , Sin Ho District , Lai Chau Province , Vietnam ( 22.2773 ° N , 103.2626 ° E , 1260 m ) on 19 September 2013 . AMS R184847, one adult female, collected in Pe Xa Forest , Sin Ho District , Lai Chau Province , Vietnam ( 22.2770 ° N , 103.2593 ° E , 1283 m ) on 19 September 2013 . AMS R184848, one adult female, collected in Pe Xa Forest , Sin Ho District , Lai Chau Province , Vietnam ( 22.2687 ° N , 103.2589 ° E , 1171 m ) on 21 September 2013 . All specimens were collected in evergreen forest over limestone terrain by Jodi J. L. Rowley, Le Thi Thuy Duong , Dau Quang Vinh, Chad Minshew, and Hoang Anh Tuan. Etymology : The specific epithet derives from the Latin petra , meaning rock, and –ops , meaning having the appearance of, in reference to both the stone-like appearance of the frog and the limestone karst in which the species was found in Lai Chau Province . FIGURE 3. Male holotype (VNMN 2016 A.06) of Leptolalax petrops sp. nov . Specimen in preservative in (A) dorsal, (B) ventral and (C) lateral view, and specimen in life in (D) dorsal and (E) ventral view. Scale bar 1mm. FIGURE 4. Leptolalax petrops sp. nov . in life from Tuyen Quang Province (A) Male holotype VNMN 2016 A.06 in situ , (B) male holotype VNMN 2016 A.06, (C) paratypes AMS R184826, (D) VNMN 2016 A.09, (E) VNMN 2016 A.11 and from Lai Chau Province (F) AMS R184845 and (G) VNMN 2016 A.16. Diagnosis : Assigned to the genus Leptolalax on the basis of the following: small size, rounded finger tips, the presence of an elevated thenar tubercle not continuous to the thumb, presence of macroglands on body, vomerine teeth absent, tubercles on eyelids, anterior tip of snout with vertical white bar (Dubois 1980; Lathrop et al . 1998 ; Delorme et al . 2006 ). The species differs from its congeners by having (1) a medium-sized body of 23.6–27.6 mm in 21 adult males and 30.3–47.0 mm in 17 adult females, (2) immaculate white chest and belly, (3) no distinct black markings on the head, (4) highly tuberculate skin texture, (5) toes lacking webbing and with narrow lateral fringes, and (6) a call consisting of an average of four notes and a dominant frequency of 5.6–6.4 kHz (at 24.5–25.3 °C). Description of holotype : Head longer than wide; snout rounded in profile and obtusely pointed in dorsal view, projecting slightly over lower jaw; nostril approximately equidistant to tip of snout and eye; canthi rostralis rounded, indistinct; lores sloping, slightly concave; vertical pupil; diameter of eye 84% length of snout; tympanum distinct, round, diameter approximately half that of the eye; vomerine teeth absent; pineal ocellus absent; large oval vocal sac openings present, located on either side of floor of mouth; tongue large, moderately broad, with wide notch at tip; distinct, raised supratympanic ridge running from corner of eye to axillary gland. Tips of fingers rounded, slightly wider than width of fingers; relative finger lengths I <II <IV <III; nuptial pad absent; subarticular tubercles absent; a large, inner palmar tubercle distinctly separated from slightly smaller, laterally compressed outer palmar tubercle; no finger webbing or fringes. Tips of toes same width as toes; relative toe length I <II <V <III <IV; subarticular tubercles absent, replaced by dermal ridges, distinct on second, third and fourth toes; oval inner metatarsal tubercle pronounced, outer metatarsal tubercle absent; webbing indistinct; narrow but distinct lateral fringes. Tibia 49% of snout-vent length; tibiotarsal articulation reaches anterior edge of eye. Skin on dorsum mostly smooth, with indistinct, low tubercles in preservative, more obvious in life; ventral skin smooth; dorsal ridges or dorsolateral folds absent; pectoral gland oval, approximately 1.2 mm diameter; femoral gland oval, 1.4 mm diameter, on posteroventral surface of thigh, closer to knee than to vent; supra-axillary gland raised, 1.2 mm diameter. Ventrolateral glandular line indistinct, present as indistinct, glands barely forming a line. Colour of holotype in life: Dorsum dull medium brown with slightly darker brown markings, the most distinct of these being a interorbital bar, a W-shaped mark on axilla, indistinct darker wash over upper tympanum, distinct dark brown barring on upper lip, and transverse barring on dorsal surface of limbs including fingers and toes; ventral surface of elbow and upper arm without dark bars; pale yellowish brown on elbows. Throat and ventral surface of arms pale pink and slightly transparent, particularly at either side of throat; edges of throat pale brown with white speckling, concentrated towards snout; ventral surface of chest and abdomen immaculate white; ventral surface of legs pinkish grey with small whitish spots concentrated on edges. Supra-axillary gland pale yellowish brown, pectoral gland cream, femoral glands cream. Iris gold in lower half and copper in upper half, with minute, black reticulations. Colour of holotype in preservative: Nearly uniform dark brown dorsal surface, with darker barring on surface of limbs including fingers and toes. Ventral surface creamy white. Ventrolateral surfaces of lower arms and tibiotarsus pale brown; Supra-axillary, pectoral and femoral glands creamy white. Measurements : Holotype (mm): SVL 24.3, HDL 9.4, HDW 9.0, SNT 43.7, EYE 2.9, IOD 3.4, TMP 1.8, TEY 0.9, TIB 12.2, EN 2.1, IN 2.4, NS 1.7, ML 6.3, PL 11.3, F1 2.3, F2 3.0, F3 4.8. Weight in life 1.8 g . TABLE 3 . Measurements (mm) of adult male Leptolalax petrops sp. nov. from Tuyen Quang and Lai Chau Provinces. Abbreviations defined in text. Measurements Tuyen Quang Province Lai Chau Province Range; Mean (N=19) Range; Mean (N=2) SVL 24.3–27.6; 26.0 23.6–27.0; 25.3 HDL 9.4–10.8; 10.1 9.1–10.9; 10.0 HDW 8.9–10.1; 9.5 8.5–10.2; 9.4 SNT 2.3–4.3; 3.8 3.7–4.0; 3.9 EYE 2.9–3.7; 3.4 3.3–3.4; 3.3 IOD 2.6–3.6; 3.2 3.0–3.2; 3.1 TMP 1.7–2.3; 2.0 1.5–2.0; 1.7 TEY 0.7–1.2; 1.0 0.9–1.2; 1.1 TIB 12.0–13.5; 12.6 11.6–13.8; 12.7 EN 1.5–2.6; 2.2 2.3–2.6; 2.5 IN 2.3–2.9; 2.6 2.5–2.7; 2.6 NS 1.3–1.8; 1.6 1.4–1.7; 1.6 ML 6.3–7.8; 7.0 6.2–7.0; 6.6 PL 11.1–12.9; 11.9 10.8–12.1; 11.5 Weight (g) 1.8–2.2; 1.9 1.6–2.2; 1.9 Range; Median (N=19) Range; Median (N=2) HDL:HDW 1.01–1.09; 1.06 1.07–1.07 HDL:SVL 0.36–0.41; 0.39 0.39–0.40 TIB:SVL 0.46–0.51; 0.48 0.49–0.51 TMP: SVL 0.06–0.09; 0.08 0.06–0.07 TABLE 4. Measurements (mm) of adult female Leptolalax petrops sp. nov. from Tuyen Quang and Lai Chau Provinces. Abbreviations defined in text.

Measurements SVL HDL HDW SNT EYE IOD TMP TEY	Tuyen Quang Province Range; Mean (N=5) 30.3–33.5; 31.8 12.0–12.8; 12.5 11.0–12.1; 11.5 4.3–5.0; 4.7 3.8–4.4; 4.1 2.9–3.6; 3.3 2.3–2.7; 2.5 1.0–1.5; 1.2	Lai Chau Province Range; Mean (N=12) 34.0–47.0; 37.9 13.3–18.5; 14.9 12.8–17.6; 14.0 4.8–7.2; 5.6 3.9–5.2; 4.5 3.4–5.3; 4.0 2.3–3.3; 2.7 1.3–3.2; 1.8
TIB EN IN NS ML PL Weight (g)	14.6–15.6; 15.1 2.7–3.1; 2.9 2.8–3.4; 3.0 1.6–2.0; 1.8 7.6–8.7; 8.1 13.9–14.7; 14.3 2.5–3.1; 2.8 Range; Median (N=5)	15.5–21.8; 17.5 3.0–4.3; 3.3 2.8–4.1; 3.3 1.7–2.8; 2.0 8.9–12.9; 10.2 14.9–20.9; 16.8 3.6–7.6; 4.6 Range; Median (N=12)
HDL:HDW HDL:SVL TIB:SVL TMP: SVL	1.06–1.14; 1.09 0.37–0.42; 0.39 0.46–0.50; 0.47 0.07–0.08; 0.07	1.02–1.09; 1.05 0.37–0.42; 0.39 0.43–0.50; 0.45 0.06–0.08; 0.07

Variation : Male L. petrops sp. nov. are smaller than females ( 23.6–27.6 mm in 21 adult males versus 30.3– 47.0 mm in 17 adult females). The 12 females from Lai Chau Province were larger than the three from Tuyen Quang Province (34.0–47.0 versus 30.3–33.5 mm ; Table 4 ). Dorsal colour in life varies from pale to medium brown, and vary in their degree of dorsal patterning. AMS R184841, AMS R184840, AMS R184831, AMS R184827, have a nearly completely unpatterned dorsum, others have weak patterning. Individuals vary in the number and size of dark spots along the flanks. Females are more tuberculate than males. In both sexes, skin texture more tuberculate in life compared to in preservative. Tubercles form ridges in some individuals. Measurements of the type series are shown in Tables 3–4 . Advertisement call : Call descriptions are based on the calls of the holotype , recorded at 24.7°C ambient temperature. Most calls were an average of 55 ms in duration and consisted of an average of 3.9 notes ( Table 5 ). Notes contained a single pulse. The dominant frequency was 6.0 kHz, and harmonics were present at approximately 12.2 and 18.2 kHz ( Fig. 5 ). A fundamental frequency was not evident. Calls were repeated at a rate of 3.4 calls per second, and had an average intercall interval of 237 ms. In six of the seven males recorded an additional call type was evident ( Fig. 5 Bi, iii). In the holotype , these calls were 347 and 351 ms in duration and consisted of 24 and 23 notes of a similar frequency and amplitude to other calls. In the calls of the seven individuals recorded, the number of notes in the most common calls varied from one to six but four was the typical number of notes. The dominant frequency varied only slightly among individuals, from 5.6–6.4 kHz (over 0.8 °C difference in ambient temperature). To the human ear, the advertisement call of L. petrops sp. nov. is a rapid, high-pitched rasping, similar to an orthopteran. Ecology: All specimens were found at night in forest between ~ 234–1283 m asl. In Tuyen Quang Province , males were observed calling from on rocks, stream banks and on vegetation within or adjacent to rocky streams in May. During surveys in Lai Chau Province in September, no males were heard calling and most frogs encountered were females, mostly located away from water on limestone karst. FIGURE 5. Advertisement call of Leptolalax petrops sp. nov. (A) 30 s waveform of relative amplitude (Rel. amp.) over time for (i) holotype VNMN 2016 A.06, (ii) paratype VNMN 2016 A.11, (iii) paratype AMS R184833, and (iv) AMS R184832. (B) 2 s waveform and corresponding spectrogram of (i) holotype VNMN 2016 A.06, (ii) paratype VNMN 2016 A.11, (iii) paratype AMS R184833, and (iv) paratype AMS R184832. All recorded at 24.5–25.3 °C. Conservation status : The species is currently known from Lai Chau and Tuyen Quang Provinces, Vietnam . The true extent of occurrence is unknown but the species probably extends further into adjoining areas of northwestern Vietnam and southern China . Suitable forested regions may include parts of Hoang Lien Son Nature Reserve, Muong Nhe Nature Reserve and Nam Don Nature Reserve in Vietnam . We recommend that the species is listed as Vulnerable on the Red List of Threatened Species as its predicted Extent of Occurrence is 19,874km 2, it likely occurs in only two threat-defined locations, and there is an observed continuing decline in the quality of its habitat, satisfying Red List Criteria B1ab(iii). TABLE 5. Measurements of advertisement call parameters for Leptolalax petrops sp. nov. from Tuyen Quang Province. Parameter values are given as means (and ranges). *holotype. AMS VNMN 2016 VNMN VNMN AMS AMS AMS R184826 A.06* 2016 A.09 2016 A.11 R184831 R184832 R184833 Primary Call duration 42.6 (10– 55.0 52.1 55.5 (51– 53.2 (50– 54.8 (52– 59.9 (57– call (ms) 57) (44–57) (5–56) 60) 55) 58) 62) Secondar Duration none 347, 351 379 228, 266 215 378, 354 217, 196 y call Notes/call 24, 23 28 16, 18 18, 21, 21 14, 13 Comparisons : Leptolalax petrops sp. nov. differs morphologically and/or bioacoustically to all known Leptolalax species. From species in the subgenus Lalos ( Dubois et al. 2010 ), distributed south of the Isthmus of Kra, Leptolalax petrops sp. nov . differs by lacking ventrolateral glands (present in the subgenus Lalos ; Delorme et al. 2006 ) and by molecular divergence ( Table 2 , Fig. 2 ).

Intercall interval	416 (337– 660)	237.4 (174– 273)	296.3 (175– 637)	408.3 (317– 568)	325.3 (286–530)	261.2 (232–375)	537.2 (299–805)
Notes/call	4.1 (1–6)	3.9 (3–4)	4.1 (4–5)	4	4	4	4
Call repetition rate	2.2	3.4	2.8	2.1	2.6	3.1	1.7
Fundamental frequency	0.2	0.2	0.2	0.2	0.2	0.2	0.2
Dominant frequency	5.7 (5.6– 5.8)	6	6.0 (5.8– 6.0)	5.8 (5.8– 6.0)	6.3 (6.2– 6.4)	6.1 (6.0– 6.4)	5.8
Harmonic 1	11.4	12.2	12	11.6	12.6	12.1	11.6
Harmonic 2	17.1	18.2	17.6	18.4	18.6
Harmonic 3	23.6	24.6

Note repetition rate	66, 63	71	66, 64	79,	53, 56	60, 61
Dominant frequency (kHz)	6.6	5.8	5.3, 5.8	6.4	5.8, 5.8	5.8, 5.6
Temperature (° C)24.5	24.7	25.1	24.7	25.3	25.2	24.8

From the 35 Leptolalax species considered to be in subgenus Leptolalax ( Delorme et al. 2006 ) or in the Leptolalax applebyi group (subgeneric placement remains unresolved; Rowley et al . 2016 ), Leptolalax petrops sp. nov . differs by a combination of morphological, molecular and/or bioacoustic data. From the 23 species with molecular data available, the new species differs in a high divergence in the 16S gene fragment examined ( Table 2 , Fig. 2 ), and by a combination of morphological and bioacoustic characters. From L. aureus , the new species differs by having highly tuberculate dorsal skin (versus finely tuberculate), having black lateral spots (versus no lateral spots), and a call consisting of 1–6 notes (average of four) (versus a call consisting of 2–16 notes). From L. applebyi , the new species differs by having a body size of 23.6–27.6 mm in 21 adult males and 30.3–47.0 mm in 17 adult females (versus 19.6–22.3 mm in males and 21.7–25.9 mm in females), having highly tuberculate dorsal skin (versus mostly smooth), an immaculate white chest and belly (versus reddish brown with white speckling), lacking distinct black markings on the head (versus black markings present), and a call with a dominant frequency of 5.6– 6.4 kHz at 24.5–25.3 °C (versus 4.0–4.3 kHz at 21.5 °C). From L. ardens , the new species differs by having highly tuberculate dorsal skin (versus mostly smooth), an immaculate white chest and belly (versus reddish brown with white speckling), lacking distinct black markings on the head (versus black markings present), and a call with a dominant frequency of 5.6–6.4 kHz at 24.5–25.3 °C (versus 3.1–4.3 kHz at 21.5 °C). From L. bidoupensis , the new species differs by having highly tuberculate dorsal skin (versus mostly smooth), an immaculate white chest and belly (versus reddish brown with white speckling), lacking distinct black markings on the head (versus black markings present), and a call consisting of an average of four notes (versus 6–9 notes) and a dominant frequency of 5.6–6.4 kHz at 24.5–25.3 °C (versus 1.9–3.8 kHz at 19–21 °C). From L. bourreti , the new species differs by having a body size of 23.6–27.6 mm in adult males (versus 36.2 mm ), highly tuberculate dorsal skin (versus mostly smooth), and lacking distinct black markings on the head (versus black markings present). From L. eos , the new species differs by having a male body size of 23.6–27.6 mm (versus 33.1–34.7 mm ), and having highly tuberculate dorsal skin (versus shagreened). From L. firthi , the new species differs by having black lateral spots (versus no lateral spots), feet with narrow but distinct lateral fringes (versus feet with wide lateral fringes in males), and a call repetition rate of 1.7–3.1 calls/s at 24.5–25.3 °C (versus <1 call/s at 21.5 °C). From L. isos , the new species differs by having black lateral spots (versus no lateral spots), feet with narrow but distinct lateral fringes in both sexes (versus feet with wide lateral fringes in males), and a call consisting of an average of four notes (versus three notes). From L. kalonensis , the new species differs by having highly tuberculate dorsal skin (versus mostly smooth), an immaculate white chest and belly (versus dark brownish with white speckling), and a call with a dominant frequency of 5.6–6.4 kHz at 24.5–25.3 °C (versus 2.8 kHz at 26.4 °C). From L. laui , the new species differs by having highly tuberculate dorsal skin (versus shagreened), and feet with narrow but distinct lateral fringes in both sexes (versus feet with wide lateral fringes). From L. liui , the new species differs by having highly tuberculate dorsal skin (versus mostly smooth), lacking distinct black markings on the head (versus black markings present), and feet with narrow but distinct lateral fringes in both sexes (versus feet with wide lateral fringes). From L. maculosus , the new species differs by having highly tuberculate dorsal skin (versus mostly smooth), an immaculate white chest and belly (versus reddish brown with white speckling), lacking distinct black markings on the head (versus black markings present), and a call with a dominant frequency of 5.6–6.4 kHz at 24.5–25.3 °C (versus 2.7–2.8 kHz at 23.3–24.1 °C). From L. melicus , the new species differs by having a male body size of 23.6– 27.6 mm (versus 19.5–22.7 mm in males), highly tuberculate dorsal skin (versus mostly smooth), an immaculate white chest and belly (versus reddish brown with white speckling), lacking distinct black markings on the head (versus black markings present), and a call with a dominant frequency of 5.6–6.4 kHz at 24.5–25.3 °C (versus 2.9– 3.8 kHz at 26.1–26.2 °C). From L. minimus , the new species differs by having highly tuberculate dorsal skin (versus mostly smooth). From L. nyx , the new species differs by lacking dark, regularly set rounded spots on the dorsum (versus dark, regularly set rounded spots present), and highly tuberculate dorsal skin (versus mostly smooth). From L. oshanensis , the new species differs by having highly tuberculate dorsal skin (versus smooth with fine glandular ridges), no distinct black markings on the head (versus black markings present), and a call with an average of four short repeated notes (versus three) and a dominant frequency of 5.6–6.4 kHz at 24.5–25.3 °C (versus 4.4–4.6 kHz at 14 °C). From L. pallidus , the new species differs by having an immaculate white chest and belly (versus brown with white speckling), and a call with a dominant frequency of 5.6–6.4 kHz at 24.5–25.3 °C (versus 2.4–2.7 kHz at 14.0–21.4 °C). From L. pyrrhops , the new species differs by having a male body size of 23.6–27.6 mm (versus 30.8–34.3 mm ), highly tuberculate dorsal skin (versus finely shagreened), an immaculate white chest and belly (versus brownish with white speckling), no distinct black markings on the head (versus black markings present), and a call with an average of four notes (versus 5–6 notes) and a dominant frequency of 5.6–6.4 kHz at 24.5–25.3 °C (versus 1.9–2.2 kHz at 21.5 °C). From L. pluvialis , the new species differs by having a male body size of 23.6–27.6 mm (versus 21.3–22.3 mm ), a highly tuberculate dorsal skin (versus mostly smooth), an immaculate white chest and belly (versus dirty white with dark brown marbling), and no distinct black markings on the head (versus black markings present). From L. tadungensis , the new species differs by having highly tuberculate dorsal skin (versus smooth), an immaculate white chest and belly (versus brown with white speckling), lacking distinct black markings on the head (versus black markings present), and a call with a dominant frequency of 5.6–6.4 kHz at 24.5–25.3 °C (versus 2.6–3.1 kHz at 12.9–22.3 °C). From L. tengchongensis , the new species differs by having an immaculate white chest and belly (versus with dark brown blotches on chest and belly), and lacking distinct black markings on the head (versus black markings present). From L. ventripunctatus , the new species differs by having highly tuberculate dorsal skin (versus mostly smooth with longitudinal ridges), an immaculate white chest and belly (versus with dark spots), and lacking distinct black markings on the head (versus black markings present). From L. zhangyangpingi , the new species differs by having a male body size of 23.6–27.6 mm (versus 45.8–52.5 mm ) and highly tuberculate dorsal skin (versus mostly smooth with distinct tubercles and longitudinal ridges). From the remaining 12 Leptolalax species in the subgenus Leptolalax ( Delorme et al. 2006 ) , no molecular data are available and their genetic differentiation to Leptolalax petrops sp. nov . could therefore not be assessed, however they differ by a combination of morphological and bioacoustics characters. From L. alpinus , the new species differs by having highly tuberculate dorsal skin (versus mostly smooth), an immaculate white chest and belly (versus dark spotting), lacking distinct black markings on the head (versus black markings present), and a call consisting of an average of four notes (versus an average of 9.5 notes). From L. botsfordi , the new species differs by having a male body size of 23.6–27.6 mm (versus 29.1–32.6 mm ), having highly tuberculate dorsal skin (versus shagreened), an immaculate white chest and belly (versus reddish brown with white speckling), lacking distinct black markings on the head (versus black markings present), and a call consisting of an average of four notes (versus 1–3 notes) and a dominant frequency of 5.6–6.4 kHz at 24.5–25.3 °C (versus 2.6–3.4 kHz at 14 °C). From L. croceus , the new species differs by having an immaculate white chest and belly (versus bright orange belly), a visible tympanum (versus indistinct tympanum), and a call consisting of an average of four short repeated notes (versus 4–6 highly variable notes). From L. fuliginosus , the new species differs by having a body size of 23.6–27.6 mm in adult males (versus 28.2–30.0 mm), highly tuberculate dorsal skin (versus mostly smooth), an immaculate white chest and belly (versus dusty), and lacking distinct black markings on the head (versus black markings present). From L. khasiorum , the new species differs by having, an immaculate white chest and belly (versus venter with darker pigments on sides), and an iris that is gold in lower half and copper in upper half (versus iris with bright orange upper). From L. lateralis , the new species differs by having highly tuberculate dorsal skin (versus finely tuberculate), a head longer than wide (versus HW>HL), and nostril closer to the snout than eye (versus closer to eye). From L. nahangensis , the new species differs by having a body size of 23.6–27.6 mm in adult males (versus male 40.8 mm ), highly tuberculate dorsal skin (versus mostly smooth), an immaculate white chest and belly (versus light specking on throat and chest), and lacking distinct black markings on the head (versus black markings present). From L. nokrekensis , the new species differs by having a highly tuberculate dorsal skin without longitudinal folds (versus dorsum with longitudinal folds), lacking distinct black markings on the head (versus black markings present) and an iris that is gold in lower half and copper in upper half (versus iris with bright red upper). From L. pelodytoides , the new species differs by having a highly tuberculate dorsal skin (versus mostly smooth with small, smooth warts) and feet with indistinct webbing (versus feet one-third webbed). From L. sungi , the new species differs by having a male body size of 23.6–27.6 mm (versus 48.3–52.7 mm ), highly tuberculate dorsal skin (versus uniformly finely granular), medium brown dorsum (versus pale creamy brown), and lacking distinct black markings on the head (versus black markings present). From L. tamdil , the new species differs by having a body size of 23.6–27.6 mm in adult males (versus male 32.3 mm ), highly tuberculate dorsal skin (versus weakly tuberculate) and an iris that is gold in lower half and copper in upper half (versus top third bright orange, lower greyish-cream). From L. tuberosus , the new species differs by having an immaculate white chest and belly (versus with black streaks), having a distinct tympanum (versus indistinct), a call with an average of four notes (versus a single note).