Xenophrys gigas Jerdon, 1870

Mahony, Stephen, Kamei, Rachunliu G. & Teeling, Emma C., 2018, Cryptic diversity within the Megophrys major species group (Amphibia: Megophryidae) of the Asian Horned Frogs: Phylogenetic perspectives and a taxonomic revision of South Asian taxa, with descriptions of four new species, Zootaxa 4523 (1), pp. 1-96 : 39-45

Neotype for Xenophrys gigas Jerdon, 1870 and Megalophrys major Boulenger, 1908 (by present designation).

Adult male (BMNH 1947.2.24.93 [rr. BMNH [18]72.4.17.399]: Figure 14 ), from Khasi Hills, Meghalaya state [previously “Darjeeling”––see Remarks section], Northeast India, collected by T.C. Jerdon, collection date ~1870. Examined specimens. Adult male (BMNH 1947.2.24.93), neotype; four adult males (BMNH 1947.2.24.94 [rr. BMNH [18]72.4.17.400]; BMNH 1947.2.24.95 [rr. BMNH [18]72.4.17.401]; BMNH 1947.2.24.96 [rr. BMNH [18]72.4.17.402]; BMNH 1947.2.24.98 [rr. BMNH [18]72.4.17.404]), two adult females (BMNH 1947.2.24.92 [rr. BMNH [18]72.4.17.398]; BMNH 1947.2.24.97 [rr. BMNH [18]72.4.17.403]), one unsexed subadult (BMNH 1947.2.24.99 [rr. BMNH [18]72.4.17.405]), and one juvenile (BMNH 1947.2.25.1 [rr. BMNH [18]72.4.17.406]), details as per the neotype; four adult males (ZSIC 9744; ZSIC 9756; BMNH 1908.4.8.4 [ex. ZSIC 9743]; BMNH 1908.4.8.5 [ex. ZSIC 9736]), one adult female (ZSIC 9746), and one unsexed juvenile (BMNH 1908.4.8.6 [ex. ZSIC 9760]) from “Cherrapunji [=Sohra]”, East Khasi Hills district, Meghalaya state, Northeast India, collected by J.H. Bourne, collection date unknown; two adult males (SDBDU 2007.229; SDBDU 2007.230), from the Terunhü River, Kenrunhü (25°55'4"N, 94°5'24"E, 510 m asl.), New Sendenyu Village, Tseminyu sub-division, Kohima district, Nagaland, Northeast India, collected by RGK on 0 3 October 2007; one adult female ( CES 18901 [field number RGK 0073]: Figure 15A & B ), from Raenghkucpaeng duithuak (duithuak = stream, in local Rongmei [ Nruangmei ] language), near St. Joseph School (24°51'40"N, 93°38'33"E, 470 m asl.), Khumhzi II village, Luangmai (Noney) district (erstwhile [before 2016] in Tamenglong district), Manipur state, Northeast India, collected by RGK on 23 May 2013 ; adult male ( CES 18902 [field number RGK 0088]: Figure 15C & D ), from Mpeih baek duithuak (24°51'0"N, 93°37'23"E, 450 m asl.), Khumhzi village, Luangmai district, Manipur state, Northeast India, collected by RGK on 26 May 2013 ; adult male ( CES 18903 [field number RGK 0089]: Figure 15E & F ), from near Khangchiuluanh ( Khongjaron ) Church (24°58'1"N, 93°29'53"E, 1255 m asl.), Khangchiuluanh village, Tamenglong district, Manipur state, Northeast India, collected by RGK on 27 May 2013 .

Neotype description (measurements in mm). Mature male (SVL 75.0) ( Figure 14 ). Head moderately large, longer than wide (HW 29.0, HL 29.7, IFE 12.6, IBE 20.9); snout bluntly pointed in dorsal view, obtusely protruding in lateral view, without rostral appendage ( Figure 14C ); loreal region acute, concave; canthus rostralis angular; dorsal surface of snout very slightly concave; eye length ~2.5 times as long as maximum diameter of visible portion of tympanum, and shorter than snout length (EL 9.2, TYD 3.7, SL 10.6); eye–tympanum distance (TYE 6.3) longer than diameter of visible portion of tympanum; tympanum oval-shaped, obliquely orientated with upper ~20% concealed by supratympanic ridge ( Figure 14C ); pupil vertically elliptical; nostril positioned laterally, closer to eye than to snout tip (EN 4.2, NS 6.5); internarial distance greater than upper eyelid width, and equal to narrowest point between upper eyelids (IN 9.4, UEW 6.0, IUE 9.4); pineal ocellus not visible externally; vomerine ridges present, medium sized, ovoid, moderately raised, orientated acutely, positioned between to slightly posterior to choanae, slightly closer to choanae than to each other; vomerine teeth short; maxillary teeth present; tongue moderately large, with small notch posteriorly, medial lingual process absent.

Forelimbs long, thin ( Figure 14A & B ), forearms moderately enlarged relative to upper forelimbs, and shorter than hand length (FAL 18.4, HAL 18.7); fingers long, narrow, without lateral fringes ( Figure 14D ), finger length formula IV<II=I<III (FIL 9.3, FIIL 9.3, FIIIL 12.0, FIVL 9.1); interdigital webbing, subarticular, supernumerary and metacarpal tubercles all absent; thenar tubercles weakly developed; finger tips flattened, slightly expanded relative to digit widths (FIIIW 2.0, FIIIDW 2.3) with subcircular pads, terminal grooves on pads absent. Hindlimbs long, thin ( Figure 14A & B ); thighs slightly shorter than shanks, and longer than feet (TL 39.7, SHL 40.8, FOL 37.1); toes long, dorsoventrally flattened with very narrow lateral fringes ( Figure 14E ), relative toe lengths I<II<V<III<IV; toe tips flattened, considerably dilated (TIVW 2.0, TIVDW 2.7), with distinct subcircular pads, terminal grooves on pads absent; webbing basal, I1.5– 2II 1–2.5 III2 –3.5IV3.5– 2V; inner metatarsal tubercles distinct (IMT 4.5), longitudinally ovoid; subarticular, supernumerary and outer metatarsal tubercles absent; ridge of callous tissue absent on ventral surface of toes.

Skin of dorsal surfaces of head and body primarily smooth with weak, densely scattered granules; tympanum with borders raised relative to surrounding region; outer edge of upper eyelid with a distinct pointed bump; supratympanic ridges narrow anteriorly, gradually expanding posterior to tympanum to become moderately enlarged and glandular, extending from posterior orbital borders, broadly curving through upper border of tympanum, terminating above forearm insertions; flanks densely covered with small to large unevenly scattered pustular tubercles; dorsolateral ridges thin, well defined, extending from behind supratympanic ridge to ~70% distance to vent; parietoscapular-sacral ridges weak, “>–<” configuration, composed primarily of single row of closely spaced asperities; dorsal surfaces of forearms, thighs and shanks with short transverse ridges; posterior thighs with small scattered pustular tubercles, remaining dorsal surfaces of forelimbs and hindlimbs otherwise smooth; gular region, chest, abdomen and ventral surfaces of limbs smooth; pectoral glands small, raised, level with axilla on chest; femoral glands large, flat, on posterior surface of thighs, slightly closer to knee than to cloaca; distinct pair of enlarged glands present adjacent to cloaca, one on each side, that are smaller than femoral glands but larger than surrounding tubercles; small black and white dermal asperities present, forming broad dense band circummarginally on gular region, dense on upper lips, lower loreal region, and tympanic region (especially dense on tympanum), moderately dense on dorsal surface of eyelids, entire dorsal surface of head and back, increasing in density posteriorly and on dorsal ridges, absent from all remaining surfaces.

Colouration: In preservative ( Figure 14 ): Dorsal and lateral surfaces of body, and dorsal and lateral surfaces of head primarily brown; light-edged, faintly darker brown triangular marking between eyes; no X-, Y-, or V-shaped markings on dorsum; tubercles primarily white on posterior flanks only; lateral surfaces of head below supratympanic ridges and canthus rostralis dark brown with cream-white stripe on upper lip, extending from nostril to rear of jaw, bordered below by thin dark brown stripe; outer edges of eyelids dark brown; dorsal and lateral surfaces of forelimbs and hindlimbs primarily mid brown; three dark brown blotches on dorsolateral surface of forearms; dorsal surface of outer three fingers with faint brown blotches; dorsal surfaces of hindlimbs without distinct transverse crossbars; lateral surfaces of thighs and shanks with dark brown spots and blotches; throat and chest primarily plain mid brown with few cream-white spots along edge of gular region, light-edged wide dark brown stripe extending from posterior edge of mandible onto base of forearms; abdomen, ventral surfaces of forelimbs, thighs, shanks, and dorsal surfaces of tarsi and feet immaculate pale brown; some small dark brown spots and blotches laterally along lower flanks on both sides bordering lower-most tubercles; area surrounding vent and posterior surfaces of thighs primarily mid to dark brown with small cream-white tubercles; ventral surfaces of tarsi and feet pale greyish-brown; hands ventrally pale greyish-brown; pectoral and femoral glands creamish-white. In life: Not documented for neotype. Refer to Figure 15 for examples of colour in life of referred specimens.

Variation. Refer to Table 1 for morphometric variation within the referred specimen series, consisting of 12 adult males, three adult females, two subadults, and a juvenile. Referred specimens generally resemble neotype for most morphological characters with the following exceptions: Webbing between digits varies slightly between individuals and sexes, i.e., webbing formula on Toe IV: males from 3.2IV3.2 to 3.6IV3.6, females 4IV 4.3; lateral fringes on toes vary from moderately weak from bases to tips on all toes, to almost completely absent on some individuals; relative finger lengths seem to vary between populations, IV<II=I<III on all “Darjeeling” specimens except a subadult (BMNH 1947.2.24.99) with IV=II=I<III, all Sohra specimens have IV=II=I<III, except a female (ZSIC 9746) with IV<II<I<III, and all aforementioned variations, with an additional IV<I<II<III for RGK 0 0 98, are observed in the Nagaland-Manipur specimens; vomerine ridges vary from sub-circular to ovoid, positioned slightly closer to choanae than to each other on many individuals; posterior edge of tongue on some specimens appears more deeply notched than others, likely due to preservation condition; dorsolateral ridges typically weak to moderately well developed, varying in length from ~60 to 90% trunk length; between ~5 and 30% of tympanum can be concealed by supratympanic ridge; dermal tubercle cover on flanks varies considerably, some with only sparse scattering of small tubercles (e.g., Figure 15A ), others with moderately dense cover of heterogeneous sized (large to small) tubercles (e.g., Figure 15C & E ); dorsal markings vary from faint to distinct complete X-shaped, Yshaped, hourglass-shaped marking, or just a V-shaped marking on parietoscapular region, not visible on some older specimens presumably due to fading; some specimens have faint spotting and blotching on chest and abdomen (e.g., Figure 15F ); density and surface coverage of dermal asperities varies extensively among male specimens, if present on females, asperities sparse on mid-dorsum increasing in density posteriorly to above cloaca, but absent from other surfaces, asperities typically absent on juvenile and subadult specimens examined; white upper lip stripe not present on metamorphs and juveniles (with SVL <50 mm), instead lateral surfaces of head plain dark brown.

Secondary sexual characters. Males: nuptial pads present, weakly raised, covered with brown/black microasperities on freshly collected specimens (appear as microgranules on old specimens), primarily covering dorsal surface of base of Finger I, narrowing distally, extending to mid-proximal phalange on inner dorsal side; nuptial pad on Finger II small, oval, positioned on base of digit on inner dorsal side (extending to mid-proximal phalange on some individuals); external vocal sac indistinct; internal vocal slit present on floor of mouth near rear of mandible, one on each side; forearms enlarged relative to upper forelimbs. Females: mature ova without pigment; nuptial pads, vocal sac, vocal slits, and enlarged forearms, all absent.

Morphological comparison. Megophrys major s.s. (adult males, N =12, adult females, N =3) differs from M. monticola and M. zhangi by its larger adult body size, male SVL 71.6–87.5 mm, female SVL 85.6–98.2 mm (vs. male SVL 38.2–49.5 mm, N =17, female SVL 40.5–56.1 mm, N =6; male SVL 32.5–37.2 mm, N =3, respectively); differs from M. robusta and M. medogensis by presence of distinct continuous whitish-cream upper lip stripe (vs. absent), by basal webbing present (vs. absent); differs from M. mangshanensis by basal webbing between toes present (vs. absent), lateral fringes on toes occasionally present (vs. absent), larger adult body size, male SVL 71.6–87.4 mm, female SVL 85.6–98.2 mm (vs. male SVL 62.5 mm, N=1, female SVL 73 mm, N=1). For comparisons with subsequent species covered in this study, refer to relevant morphological comparison sections for those species.

Systematic position. OTU 5 (“ M. cf. major 3”) in the molecular analyses of this study and Mahony et al. (2017) represents Megophrys major s.s. The systematic position of M. major s.s. within the MMC clade is not fully resolved ( Figures 2–5 ; Appendix I, Table 3; Appendix II, Figures 1 , 2 & 5 : as M. cf. major 3/OTU 5). It was consistently found to be the sister taxon to a new species (OTU 7/“ M. cf. major 1”) described below, but it is not yet clear which species these sister taxa are most closely related to within the MMC. Uncorrected p -distance for the 16S rRNA gene between these sister taxa was 6.4–6.5% (Appendix I, Table 6).

Etymology. The original species epithet “ gigas ” is derived from the Greek word meaning “giant”, later replaced with “ major ”, Latin for “large”.

Suggested common name: Jerdon’s White-lipped Horned Frog.

Distribution. This species was considered widespread from Northeast India to southeastern Vietnam but M. major sensu lato (s.l.) is now known to represent a species complex ( Chen et al. 2017; Mahony et al. 2017; this study). Only the following localities (between 450 and 1255 m asl.) represent the verified distribution of M. major s.s. ( Figure 8A ): Sohra [=Cherrapunji], in the East Khasi Hills district, Meghalaya state; Khumhzi, in Luangmai district and Khangchiuluanh, in Tamenglong district, Manipur state; and Tseminyu, in Kohima district, Nagaland. The locality “Darjeeling” associated with Jerdon’s BMNH series of specimens is considered erroneous (see Remarks for details). The eastern distribution limit for M. major s.s. is currently unclear, but it might be expected to extend into adjacent areas of western Myanmar. A report of this species from Tura Peak, West Garo Hills district in Meghalaya state was provided by Sangma and Saikia (2015). The authors provided no diagnostic characters for their specimens so the taxonomic identity of animals from this locality warrants careful investigation considering our study identifies the presence of three MMC species in Meghalaya state.

Habitat and natural history. There have been many observations and notes published regarding M. major s.l., primarily from Southeast Asian countries (e.g., Bain & Nguyen 2004; Ohler et al. 2000; Stuart 1999, 2005), which are likely to represent different species. Some old reports of M. major tadpoles (e.g., Annandale 1912) from Northeast India are not considered reliable, since most tadpoles were identified by association of adult frogs present in the collection stream, not accounting for the fact that in our experience most streams in Northeast India are inhabited by two or more Megophrys species. Based on our observations of recently collected specimens, a female (CES 18901) collected towards the end of May contained mature ova, and males were found calling during May (CES 18902, CES 18903) and October (SDBDU 2007.229, SDBDU 2007.230), indicating that the breeding season for this species probably extends from the pre-monsoon (May) until post monsoon (October). SDBDU 2007.229 and SDBDU 2007.230 were found calling amongst fallen and dead reeds on the banks of the Terunhü River in Nagaland at around 18:30 h (just after dusk). The Terunhü River at the collection locality is a moderately fast flowing stream passing through a disturbed secondary forest patch. CES 18902 was found calling during the daytime perched ~ 2.3 m above ground level on a leaf of a wild cardamom on the bank of the Mpeih bak duithuak (stream). CES 18903 was found calling from a hole in the retaining wall where a clear water stream exits an underground diversion. The gravid female (CES 18901) was collected nearby an unnamed stream. No further individuals could be located along that stream during the subsequent two nights of searching, indicating that breeding activity had not yet reached a peak (or was experiencing a lull).

Remarks. On Xenophrys gigas Jerdon, 1870 : The original type series of Xenophrys gigas consisted of five syntype specimens in Jerdon’s personal collection collected from “ Sikim [sic] and the Khasi Hills” ( Jerdon 1870). Soon after the description of Jerdon’s X. gigas, Anderson (1871b) stated “I have a specimen of Dr. Jerdon’s X. gigas beside me [in the Indian Museum (now ZSIC)], but I find that in no way differs from the Darjeeling large specimens, which are the adults of this species [ Xenophrys monticola Günther, 1864 ]”. With that statement, X. gigas was regarded to represent a junior synonym of X. monticola for the subsequent four decades. Sclater (1892b:33) listed all Indian Museum amphibian specimens by numbers, localities and collectors, which included seven specimens of “ X. monticola ” sensu Anderson (1871b) deposited by Jerdon, six from “Darjeeling” (ZSIC 9673–9677, ZSIC 9721) and one from “Khasia Hills” (ZSIC 9679). We know now (discussed below) that the large species from Darjeeling that Anderson (1871b) was referring Jerdon’s X. gigas specimen to is M. robusta . However, it is not clear whether that particular specimen was one of Jerdon’s five syntype specimens of X. gigas . Deuti et al. (2017) referred five of the aforementioned “Darjeeling” specimens (ZSIC 9673–9677), and three others not mentioned by Sclater (1892b; ZSIC 9722–9724) to Megophrys sanu comb. nov. (as juveniles). The taxonomic identities of ZSIC 9721 and ZSIC 9679 require clarification.

The whereabouts of the original type series of Xenophrys gigas , and which specimens actually belong to the original type series of this species, is an imbroglio. Chanda et al. (2000) referred four specimens (ZSIC 9670, ZSIC 9681, ZSIC 10777, ZSIC 10779) as types of X. gigas Jerdon , from “Darjeeling”, West Bengal, India. ZSIC also have an additional two specimens from Darjeeling that they regard to be the types of X. gigas (ZSIC 9650 and ZSIC 9668) (SM per. obs. during a visit to the ZSIC in 2010). Several problems exist with the recognition of these six ZSIC specimens as the types for this species: 1) all of these specimens were collected by J. Gammie ( Sclater 1892b:33 [as Leptobrachium monticola ]); Jerdon (1870) clearly stated that he “obtained” the type specimens from the type localities—Jerdon acknowledged throughout this paper when specimens were sent to him by other collectors, so it may be interpreted that he (or his party) were the collectors of the specimens; 2) ZSIC 9650 (SVL 51.1 mm) is a gravid adult female M. monticola (SM per. obs.). ZSIC 9668 was not examined in detail but is either an adult M. monticola or a juvenile M. robusta ––both specimens do not fit Jerdon’s original description by being “large”, presumably relative to the considerably smaller Xenophrys monticola , the only other Xenophrys species known at that time; 3) ZSIC 10777 and ZSIC 9681 are M. robusta (SM per. obs.); 4) Sclater (1892a, 1892b) provided a list of types in the Indian Museum that included only one megophryid, Scutiger (as Cophophryne ) sikkimensis ( Blyth, 1855), and Sclater (1892a) explicitly stated that the collections then contained the types of only one of Jerdon’s species, Hyla annectans ( Jerdon, 1870) .

Before leaving India, Jerdon visited and collected specimens in and around Darjeeling–Sikkim and the Khasi Hills, but he notoriously did not maintain notes on his collections, relying largely on memory for details of localities ( Günther 1875). Upon his return to England, Jerdon assisted Günther with the accessioning of his collection into the BMNH– –“The work of systematically arranging and naming this collection was carried on jointly by him [Jerdon] and myself, and proceeded as far as the genus Tropidonotus , when it was interrupted by an illness from which he never recovered….and I am therefore ignorant of the habitat [collection localities] of a part of the specimens which were still unexamined at the time of his death” ( Günther 1875). Jerdon’s original “ X. gigas ” collection consisted of a series of presumably 17 specimens (BMNH [18]72.4.17.398–414), and was one of the last taxa from his collection to be accessioned (BMNH Accession Register). The BMNH Accession Register gives the locality “Darjeeling (& Khasia)”, but the locality appeared in subsequent literature as Darjeeling only (e.g., Boulenger 1882 [“h”]). Doubts regarding whether some of Jerdon’s other herpetological specimens were from the Khasi Hills or from Darjeeling have been noted elsewhere (e.g., the type locality of Ixalus jerdoni Günther, 1876 [= Frankixalus jerdoni ] from “Darjeeling” was subsequently found to be widespread in the Khasi Hills [ Biju et al. 2016] but not reported from Darjeeling or surrounding regions since its original description). Jerdon deposited most (if not all) of his type specimens in the British Museum and Indian Museum, but since the Indian Museum did not (according to Sclater [1891a, 1891b]) contain Jerdon’s megophryid type specimens, the BMNH specimen series may have contained some, or all, of the five original specimens based on which Jerdon (1870) coined the name.

Remarks on Megophrys major Boulenger, 1908 : Xenophrys gigas was subsequently transferred to the genus Megalophrys by Boulenger (1908) rendering Megalophrys gigas ( Jerdon, 1870) a junior homonym of Megalophrys gigas Blyth, 1855 [now Nanorana liebigii ( Günther, 1860) ]. To correct this, Boulenger (1908) coined the replacement name Megalophrys major , and provided a morphological description of the species with a note that Jerdon (1870) named X. gigas based on specimens from Darjeeling and the Khasi Hills “now preserved in the British Museum [now NHMUK] and Indian Museum [now ZSIC]”. Considering Sclater (1892a, 1892b) did not recognise types for this species in the Indian Museum, and up until Boulenger (1908), none of Jerdon’s NHMUK Megophrys specimens were recognised as “types” of X. gigas (e.g., Günther 1876; Boulenger 1882:442), the provenance of Boulenger’s statement is unclear. In Boulenger’s (1908) account of X. gigas (as M. major ), he identified two specimens (an adult male and an adult female– –accession numbers not given) as “type” for which he provided measurements, but parts of his morphological description clearly indicated that he included many other specimens. It is unclear whether Boulenger regarded the entire specimen series to be types, or only the two specimens mentioned, however, in the absence of stringent and universally accepted nomenclatural rules governing typification at that time, Boulenger may have designated specimens collected by Jerdon as types as an attempt to remove further ambiguity. The BMNH Specimen Catalogue currently lists all 17 of Jerdon’s original specimen series as “ syntypes ” of M. major , but there is no indication in the BMNH Accessions Register that these specimens were originally considered to be the types of X. gigas . According to the Code (Article 72.7), a replacement name is an objective synonym, and must have the same type series as the original name, therefore, in the absence of evidence that Boulenger’s “type[s]” represent two of the five syntypes of X. gigas , his typification should be considered invalid.

Currently, half of the NHMUK “ syntype ” series (BMNH [18]72.4.17.407–414) are no longer present in the collection and must be assumed to have been exchanged with other museum collections prior to the 1947 replacement numbers (e.g., MCZ A-6814, received on exchange from the “British Museum” in 1920 [MCZbase, online catalogue, accessed 20 January 2018]). The remaining adult specimens in the “ syntype ” series in the NHMUK appear to be homogeneous, however, the specific status of the subadult female and juvenile specimens cannot be confirmed based on morphological characters alone. Aside from Jerdon’s NHMUK specimen series, all of which were regarded by Günther (1872) to have been collected from Darjeeling, we are aware of no subsequent collections of M. major s.s. from north of the Brahmaputra river– – Daniel (1962) reported M. major from Darjeeling based on two specimens but the figured animal clearly portrayed a M. robusta , and Subba et al. 2016 did not observe this species in Sikkim. However, we demonstrate that M. major s.s. is present in the southern Khasi Hills and adjacent areas, thus it more likely that Jerdon’s NHMUK specimen series came from there. Until the time specimens referable to M. major s.s. are collected from Darjeeling/ Sikkim area (which we consider unlikely), we regard Jerdon’s NHMUK specimen series to have been collected from the Khasi Hills, Meghalaya state, Northeast India. Likewise, we confirm that M. robusta is only found west of the Brahmaputra (including the Darjeeling area). Therefore, the name X. gigas was coined based on more than one species ( M. robusta and one or more of the Khasi Hills-endemic MMC species). Since Jerdon deposited no specimens of M. robusta in the NHMUK, it is certain that the NHMUK “ syntype ” series cannot contain all of the original type specimens of X. gigas .

Proposed Nomenclatural Resolutions: Although the syntype specimens of Xenophrys gigas might not actually be lost or destroyed, the knowledge as to which (if any) of Jerdon’s specimens represent this series is effectively “lost” so that they are no longer unambiguously identifiable. Jerdon’s (1870) original description of Xenophrys gigas provided no diagnostic characters that can permit either the identification of an existing specimen as one of the syntypes, or the application of the name to a single biological species, so Xenophrys gigas is therefore considered a nomen dubium. To resolve the nomenclatural conundrum and bring nomenclatural stability to the species name by restricting its use to a single biological species, we propose that one of the NHMUK specimens (BMNH 1947.2.24.93 [rr. BMNH [18]72.4.17.399]––described above) collected by Jerdon is designated as the neotype of Xenophrys gigas . This action will reinstate the recognition of Xenophrys gigas Jerdon, 1870 as a primary objective synonym of Megalophrys major Boulenger, 1908 , and will also preserve the nomen M. robusta for the large species of Megophrys from Darjeeling. The neotypification of this specimen will also restrict the type locality of X. gigas , and by implication that of M. major , to “Darjeeling”, corrected herein to “Khasi Hills” (which currently encompasses the East Khasi Hills and West Khasi Hills districts), Meghalaya state, Northeast India. By this action, the remaining NHMUK specimens in the series (BMNH 1947.2.24.92, BMNH 1947.2.24.94–99, BMNH 1947.2.25.1) and those in the ZSIC regarded by Chanda et al. (2000) to represent the syntype series of X. gigas will no longer be referred to as name-bearing type specimens for this taxon.

Figures

FIGURE 1. Ultrametric guide tree topologies used for BPP analyses: A. topology based on *BEAST analyses of phased nuclear alignments, with posterior probability values for nodes; B. alternative topology guide tree based on the results of concatenated mt+nuDNA gene tree analyses (Dataset E); C. alternative topology based on *BEAST analyses of unphased nuclear alignments, with posterior probability values for nodes. Taxon names in pink represent the eastern clade, blue represents the western clade (southern subclade), and green represents the western clade (northern subclade). Refer to Appendix I, Table 2 for revised names for taxa based on the taxonomic review.

FIGURE 2. BI concatenated gene tree based on the 47 taxa concatenated mt+nuDNA alignment (Dataset C), with ML node values provided. Posterior probability/bootstrap values>95% in both analyses are represented by a black spot on the node, values <95% in one or both analyses are provided next to relevant nodes, where * is>95%, and – is given for nodes that were not resolved on the ML tree. Taxon names in pink represent the eastern clade, blue represents the western clade (southern subclade), and green represents the western clade (northern subclade). Revised names for taxa based on the taxonomic review are provided in parentheses.

FIGURE 3. Concatenated gene trees based on the 29 taxa concatenated nuDNA alignment (Dataset D): A. RAxML tree; B. MrBayes tree. Posterior probability/bootstrap values are provided next to associated nodes. Taxon names in pink represent the eastern clade, blue represents the western clade (southern subclade), and green represents the western clade (northern subclade). Refer to Appendix I, Table 2 for revised names for taxa based on the taxonomic review.

FIGURE 4. RAxML tree for the combined mt+nuDNA dataset expanded to include the Chen et al. (2017) sequences (Dataset J). Bootstrap support values are provided adjacent to the associated nodes. Refer to Appendix I, Table 2 for revised names for taxa based on the taxonomic review.

FIGURE 5. DensiTree cloudogram representations of *BEAST analyses, removing the first 10% of trees as burn-in, produced from the four nuDNA gene alignments of Dataset E: A. original unphased; B. phased. Dark blue branches represent the most frequently occurring topology, light blue branches represent the consensus trees with intensity proportional to the frequency of the topology in the dataset, and green areas represent all topologies in the dataset. Refer to Appendix I, Table 2 for revised names for taxa based on the taxonomic review.

FIGURE 8. Distribution map of the western MMSG taxa: A. All taxa (excluding M. monticola) from Northeast India and surrounding countries: diamonds represent type localities, circles represent referred localities based on molecularly sampled specimens: orange = M. zhangi; yellow = M. robusta; black = M. medogensis; dark blue = M. major; pink = Megophrys flavipunctata sp. nov.; dark green = Megophrys oreocrypta sp. nov.; light blue = Megophrys himalayana sp. nov.; light green = Megophrys periosa sp. nov.; pale blue = M. cf. periosa; purple = M. glandulosa. B. Inset rectangle in Figure A enlarged to show the distribution map for M. monticola from Darjeeling and Sikkim region, Northeast India, showing distribution of named mitochondrial haplotypes: stars represent the type localities, circles represent referred localities confirmed from sequence data: red = M. “sanu” comb. nov., light blue = M. “katabhako” comb. nov. Blue lines represent major rivers; grey lines represent international borders.

FIGURE 14. Megophrys major neotype: adult male (BMNH 1947.2.24.93: SVL 75.0 mm) in preservation: A. dorsal view; B. ventral view; C. profile view of head; D. ventral view of hand; E. ventral view of foot.

FIGURE 15. Megophrys major: A–F. referred specimens from Manipur: A. and B. an adult female (CES 18901: SVL 98.2 mm) in life: A. dorsolateral view; B. ventral view; C. and D. an adult male (CES 18902: SVL 80.0 mm) in life: C. dorsolateral view; D. ventral view; E. and F. an adult male (CES 18903: SVL 81.1 mm) in life: E. dorsolateral view; F. ventral view.