Rhinophis martin Gower & Sampaio & Vidanapathirana & Mendis Wickramasinghe 2024, sp. nov.
Creators: name: Gower, David J.
name: Sampaio, Filipa L.
name: Vidanapathirana, Dulan Ranga
name: Mendis Wickramasinghe, L. J.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Squamata
Uropeltidae
Rhinophis
Rhinophis martin

description: Rhinophis martin sp. nov.
Figs. 1–6; Tables 1–3; Appendix 1
urn:lsid:zoobank.org:act: 6DA63C7E-C8D3-4318-83C4-18B1F5D7ACDC
Chresonymy
Rhinophis sp. (Deniyaya): Sampaio et al. (2023)
Holotype. USNM 548119 (Fig. 1, Table 1), adult female, “Hayes/Gongala”, Sabaragamuwa Province, Sri Lanka. Hayes (6.37° N, 80.65° E; ca. 820 m) is a tea estate and Gongala is a nearby mountain (peaking at 6.386° N, 80.654° E; 1,358 m elevation), <2 km to the north-northwest on the eastern edge of Sinharaja Forest Reserve, part of the Rakwana Massif (Fig. 2). Collected by Lalith Jayawickrama, 24 October 1979.
Paratypes (n = 10; Table 1). USNM 548100 (female) collected “Hayes”, 10 August 1977. USNM 548117 and 548118 (males) collected “Hayes/Gongala”, 24 October 1979. USNM 548120 (female), 548121 (female), 548122 (male), and 548123 (male) collected “Hayes/Gongala”, 26 October 1979. All seven of these USNM paratypes were collected by Lalith Jayawickrama. NMSL-NH 2024.01.01 (female) and NMSL-NH 2024.01.02 and DWC 2024.05.01 (males) collected from Burusgala, near Deniyaya, Southern Province, Sri Lanka (6.38° N, 80.60° E; ca. 750 m) by Dulan Ranga Vidanapathirana and L. J. Mendis Wickramasinghe, 22 August 2018.
Referred specimens (n = 22; Table 2). Eight males, 11 females, and three incomplete specimens for which sex is less confidently inferred (Table 2): USNM 548096–548099 and 548101–548110 collected by Lalith Jayawickrama from Hayes 14 July–18 August, 1977; USNM 548111–548116, 548124, 548125 collected by Lalith Jayawickrama from Hayes/Gongala 24–26 October, 1979. These are considered referred rather than type material because they were examined in less detail than the type series.
Diagnosis. A Rhinophis restricted to the Rakwana Massif of Sri Lanka with 17 dorsal scale rows at midbody, more than 166 and fewer than 190 ventral scales (167–186 in the 33 known specimens; 167–178 in males, 175–186 in females), a large, domed tail shield with small, homogenous spines, and a distinctive colour pattern (at least in adults) with a dark belly and paler, orange-bronze dorsum (except for darker anterior sixth) with irregular, blackish transverse markings.
Rhinophis martin sp. nov. differs from all six Indian species of Rhinophis by having a ventral count of> 165 and <190 (versus more than 200 in R. goweri Aengals and Ganesh, 2013, fewer than 150 in R. travancoricus Boulenger, 1893); and in having 17 dorsal scale rows at or just behind midbody (versus 15 in R. fergusonianus Boulenger, 1896, R. sanguineus Beddome, 1863, R. melanoleucus Cyriac, Narayanan, Sampaio, Umesh & Gower, 2020, and R. karinthandani Sampaio, Narayanan, Cyriac, Venu & Gower, 2020.
Among Sri Lankan congeners, Rhinophis martin sp. nov. differs from R. saffragamus (Kelaart, 1853) in not having a flat tail shield or midline contact between the opposite nasal shields, and by having dorsal scales in 17 rather than 19 rows at midbody. The new species differs from R. melanogaster (Gray, 1858), R. phillipsi (Nicholls, 1929), and R. roshanpererai Wickramasinghe, Vidanapathirana, Rajeev & Gower, 2017 in having homogenously sized spines on a regularly domed tail shield (versus a less prominent and more-irregularly shaped tail shield with heterogeneously sized spines). Rhinophis martin sp. nov. differs from R. dorsimaculatus Deraniyagala, 1941, R. oxyrynchus (Schneider, 1801), R. porrectus Wall, 1921, R. punctatus Müller, 1832 and R. zigzag Gower & Maduwage, 2011 by having fewer than 190 ventral scales (versus more than 205). Rhinophis martin sp. nov. differs from R. tricoloratus and R. erangarviraji Wickramasinghe, Vidanapathirana, Wickramasinghe & Ranwella, 2009 in having more than 166 ventral scales (versus fewer than 164). Rhinophis martin sp. nov. has more ventral scales (ca. 167–178 in males, 175–186 in females) than both R. blythii Kelaart 1853 (ca. 148–158 and 155–167, respectively) and R. philippinus (154–168 and 164–179, respectively), and additionally differs from the former in having a more protuberant, conical (versus less-prominently domed) tail shield and from the latter in having a paler orange-bronze dorsum (versus darker, brown-grey) and having (versus lacking) substantial yellow-orange markings on the underside of the tail. Rhinophis martin sp. nov. has fewer ventral scales (ca. 169–178 in males, 175–186 in females) than R. lineatus Gower & Maduwage, 2011 (183–190 and up to 195, respectively), and has a darker ventral than dorsal surface (versus vice versa). Rhinophis martin sp. nov. differs from R. mendisi Gower, 2020 by having a more rounded than ridged dorsal apex to the rostral shield (in transverse section), having more ventrals (ca. 167–178 in males, 175–186 in females versus 159–177), males typically having more subcaudals (at least 6 on one side to 7 [very rarely 5], versus 4–5 on each side), and having a darker venter than dorsum (versus darker dorsum than venter). The new species differs from R. homolepis (Hemprich, 1820) in having fewer ventrals (<187 versus>191: see Gower 2020). Rhinophis martin sp. nov. differs from R. gunasekarai Wickramasinghe, Vidanapathirana, Wickramasinghe & Gower, 2020 in having a much broader tail shield relative to tail width, in lacking narrow, continuous longitudinal yellow lines on the dorsum, and in having pale markings on the underside of the tail.
The ventral and subcaudal counts in the new species overlap substantially with those for R. drummondhayi Wall, 1921 (although with slightly higher ranges), and both have a relatively broad tail shield; however the two species differ clearly in colour pattern (paler dorsum than venter in the new species versus the reverse in R. drummondhayi), in distribution (Rakwana Massif in the new species versus Central Highlands in R. drummondhayi), in the shape of the tail shield (more prominent and conical in R. martin sp. nov.), and in DNA sequence data (with phylogenetic analysis of these data providing maximal support for R. martin sp. nov. being more closely related to R. homolepis and R. tricoloratus versus R. drummondhayi being more closely related to R. blythi, R. erangaviraji, R. lineatus and R. zigzag: Sampaio et al. 2023). Rhinophis martin sp. nov. also differs notably from all other named congeners in DNA-sequence data (Table 3; Sampaio et al. 2023), as discussed in the Remarks section below.
Description of holotype. See Table 1 for morphometric and meristic data, and Fig. 1 for photographs. Good condition; few superficial scratches to some scales. Head small, snout pointed. Rostral pointed, longer than wide, without dorsal crest; widest at level of anterior upper corner of first supralabials. Rostral many (>8) times longer (in dorsal view) than rostral-frontal gap. Frontal irregularly hexagonal, longer than wide, lateral (ocular) margins slightly converging posteriorly, posterolateral margins straight to very slightly concave; lateral (ocular) margin shortest, posterolateral edges longest. Frontal much shorter, wider than rostral. Paired nasals separated from each other by posterior half of rostral. External naris small, subcircular, slightly countersunk within small depression, located in anteroventral corner of nasal. Nasal contacts supralabials 1 and 2. Prefrontals only briefly in contact with each other along midline (left overlapping right), separating frontal from rostral. Prefrontals wider than long, shorter than frontal. Supralabials four, first smallest, making the least contribution to margin of mouth; fourth much the largest. Ocular contacts supralabials 3 and 4. Eye distinct, diameter approximately 0.3 times length of ocular, located near anterior corner of ocular, bulging slightly from ocular surface, pupil circular. Paired parietals longer than wide, approximately as long as but much wider than frontal, posteriorly broadly rounded, angle between posteromedial and posterolateral edges approximately 90°. Opposite parietals in brief midline contact (longer than contact between opposite prefrontals), left overlapping right. Each parietal contacts four scales other than head shields. No mental groove; mental approximately as wide as long, smaller than infralabials, contacting first infralabials but not first ventral; three pairs of infralabials, second largest, first smallest. First and second ventrals longer than wide, third approximately as long as wide, fourth and subsequent ventrals wider than long. Seven maxillary and eight mandibular teeth on each side. Teeth simple, pointed, distinctly retrorse, straight, evenly spaced.
Body cylindrical. Body scales generally evenly sized on dorsum and along body except for those involved in dorsal scale row reductions. Midline ventral scales between mental and anal of even size though anteriormost ones gradually narrow. At midbody, ventrals 1.24 times width of scales in first dorsal row. Ventrals 186. Dorsal scale rows 19 anteriorly, reducing to 17 by level with 41 st ventral and maintained along most of body; scale row reduction formula:
4 + 5 (41)
19 --------------- 17
4 + 5 (38)
Dorsal scale rows approximately 13 at base of tail. Head and body scales macroscopically smooth, lacking keels. Very faint, low, short keels towards posterior edges of small scales overlapped by anals and on lower dorsal scales of tail. Paired anal scales (right overlying left) considerably larger than posteriormost ventrals and subcaudals. Distal margin of each anal overlaps four (left) and three (right) other scales in addition to anteriormost subcaudals. Three subcaudals, last two undivided. Tail ‘shield’ broadly rounded cone, forming tip of tail, wider than long in dorsal view, many times longer than the frontal in dorsal view (a little shorter than distance between snout tip and back of frontal), visible from below and especially above, base surrounded by 11 scales (including last subcaudal). In posterior view shield circular to very slightly egg-shaped, wider ventrally than dorsally. Shield surface densely spinose, spines small and evenly sized, slightly posteriorly hooked (slightly dorsal upper margin, slightly concave posterior margin in lateral view) arranged in narrowly spaced rows approximately convergent on apex of shield. No notable ridges on scales of the tail and posterior end of body.
Colour in alcohol. Tip of rostrum pale orange. Head shields otherwise generally brown with pale tan distal thin margins; a slightly larger, diffuse pale area across posterior of nasals and anterior of prefrontals. Lower edges of supralabials more irregularly and broadly pale. Three dorsally incomplete, narrow (one scale wide, distributed across two scales) whitish transverse bands behind head on dorsum, each band separated by length of four to five dorsal scales.
Ventral body colour and pattern more uniform than dorsal. Ventrally brown; paler (pale orange-tan) at head end. Slightly punctate, more so anteriorly, by virtue of each scale having a brown core and pale (mostly latero-) distal edges (the posterior distal edge typically almost transparent). Scale bases and centres mostly uniformly coloured, but flecked in the paler anterior region of the venter. Among ventrals, only 5 th and 6 th are entirely pale, as are a couple of adjacent lower dorsal scale row scales plus the mental and first infralabials. Further posteriorly, occasional ventrals with larger whitish patch; 7 th ventral anterior to anal shields is entirely whitish.
Dorsally, anterior ca. 30mm dark brown, then abruptly and increasingly (coppery) orange-brown where scales are darkly flecked scales and have darker latero- and (especially) posterodistal edges. Midvertebral dorsal scale row with faintly indicated, narrow brown line each side. Darker, narrow, subparallel (4–5 scales apart) transverse dorsal bars (not dorsally complete; some asymmetrically arranged) taper upwards from dorsolateral apex of body, only one scale wide at dorsal end. Transition between darker more regular ventral colour and paler dorsal colour is somewhat irregular but typically lies on the 5 th dorsal scale row. A few isolated scales along the 5 th dorsal scale row largely or entirely whitish.
Subcaudals and first dorsal scale row mostly blackish with pale (yellowish) laterodistal and translucent posterior margins (more pale edges), together forming a posteriorly tapering, dark midventral tail stripe. Either side of this dark midventral region, the tail has a yellowish lateral tail stripe along its length from the vent to the tail shield, approximately 1.5 dorsal scale rows thick; anteriorly this stripe is much thicker, extending up onto the dorsum to form a transverse, middorsally incomplete pale band. Dark scales on upper and lower surface of tail darker than on body. Tail shield orange-yellow at apex and along ventral and ventrolateral outer edge, with almost symmetrical blackish blotches extending to dorsolateral outer edges; approximately half of shield surface orange-yellow, half blackish.
Variation in paratypes. Condition generally good. See Table 2 for some meristic and morphometric data, and Figs. 3 and 4 for photographs. In scalation all paratypes resemble the holotype except where noted here. In five paratypes (USNM 548100, 548122; NMSL-NH 2024.01.01, 2024.01.02; DWC 2024.05.01) the rostral contacts the frontal and prevents midline contact between opposite prefrontals. USNM 548100 and NMSL-NH 2024.01.02 each have a small (temporal-like) scale separating the parietal from the fourth supralabial on each side, much smaller on the left in USNM 548100 (among uropeltids, temporals occur consistently only in Brachyophidium, Teretrurus and Platyplectrurus). Left parietal overlaps right in all except USNM 548118 and NMSL-NH 2024.01.02; where prefrontals overlap, left lies above right in all except USNM 548120 and 548121. Eye 0.2–0.3 times length of ocular. In two paratypes (USNM 548118, 548120) the first ventral does not contact the first infralabials. Scale row reductions simple (see Appendix 1), reducing from 19 to 17 dorsal scale rows by level with the 31 st to 42 nd ventral without apparent sexual dimorphism. Ventrals in female paratypes 175–181, males 167–174; subcaudals in female paratypes 3,3 or 4,4, in males 6, 6 in all except 5, 5 in DWC 2024.05.01 and 7, 6 in USNM 548123. At midbody, ventrals 1.2–1.33 times width of scales in first dorsal row. At least one pair of subcaudals is ‘fused’ (undivided) in all paratypes except USNM 548118 and NMSL-NH 2024.01.02. Scales around the tail shield 10–13. Most paratypes lack notable ridges on scales in the tail and posterior end of body; low ridges on upper posterior tail dorsal scale row scales in USNM 548117 and 548121, short low ridges on posterior ends of some tail dorsal scale row scales in 548122. Teeth not counted except in USNM 548122, which resembles the holotype in having seven maxillary teeth per side, but differs in having seven rather than eight teeth in each mandible.
Paratypes similar in colour and pattern to holotype, with minor variations. All paratypes lack pale patch across posterior of nasals and anterior of prefrontals; USNM 548100 with sinuous pale band across posterior of oculars and prefrontals and anterior of frontal. Whitish transverse bands on dorsum behind head typically shorter and/or more irregular and asymmetrical in paratypes than in holotype, forming spots or subtriangular patches rather than bands. One or two pale ventral scales and adjacent dorsal scale rows anteriorly (between ventral 3–5) in most paratypes; USNM 548117 with mostly pale venter for ca. 20 mm behind third ventral; USNM 548122 without pale anterior patches ventrally. Final one or two ventrals pale in all paratypes except USNM 548117, 548118 or 548122. Background body colour paler in USNM 548100, darker in 548123. Darker pair of paravertebral longitudinal lines particularly faint, diffuse and incomplete in USNM 548100, particularly clear in 548120. Dark dorsal cross bars similar to holotype in USNM 548117, 548121 and 548122 but less tall and more triangular or irregularly spot-like in other paratypes. Border between darker dorsum and paler venter on 5 th or between 5 th and 6 th dorsal scale row. Whitish spots along 5 th dorsal scale row absent in USNM 548118 and 548122, forming notably larger, elongated pale patches with darker lower and upper rims in USNM 548123. First dorsal scale row on tail with blackish dots in USNM 548100, only blackish on a few scales in 548121, only blackish on anteriormost scales in 548120, not blackish in 548123. Pale lateral stripe on tail less regular and complete in paratypes, absent in USNM 548122, thicker (two or more dorsal scale row scales thick) in 548120 and 548123, restricted to posterior end of tail in 548100 and 548118. Dorsolateral yellow cross bars on anterior of tail absent in USNM 548118, short and broadly incomplete in 548122, narrow and almost middorsally complete in 548117. Shield more orange-yellow in USNM 548121, mostly dark in 548118 and 548122 and especially in 548117 and 548123 in which dark patches extend almost to apex.
Referred specimen variation. Some meristic and morphometric data presented in Table 2. In two specimens (USNM 548106, 548113) the rostral contacts the frontal and prevents midline contact between opposite prefrontals. Left parietal overlaps right in all except USNM 548109; where prefrontals overlap, left above right in all except USNM 548096, 548097, 548103, 548107, and 548111. Temporal-like scale on each side in USNM 548096, on right in USNM 548101. Frontal partly fused with right prefrontal in USNM 548098. All have 3,3 infralabials except USNM 548101 (3,4). First and second ventrals in contact in all except USNM 548098 and 548111). Right anal shield overlies left in all specimens except female specimens USNM 548103, 548111, and 548114. Scales around shield 10–13. Ventrals in males 169–178, females 179–186; subcaudals in males 5–7 per side, females typically 3–4 per side (two on one side on USNM 548107; five on one side in USNM 548115). Most referred specimens lack notable ridges on scales in the tail and posterior end of body; if present then typically low and on upper posterior dorsal scale row scales on tail, also on posteriormost subcaudals in, for example, USNM 548097, 548098, and 548114.
Sexual dimorphism. Variation in the number of ventrals, subcaudals and in relative tail length is strongly bimodal across the sample as a whole (Fig. 5).
Colour in life. In life (Fig. 6), the dorsal areas that are orange-brown in preserved specimens are golden yellow, and the brownish ventral colour seen in preservation is more blackish. The off-white markings on the lateral and ventral surfaces of preserved specimens are whitish in life. The pale yellowish white markings on the lateral surface of the tail of preserved specimens are similarly coloured in life. One uncollected, small specimen (<150 mm total length) had a more whitish than black or brown venter but otherwise resembled the larger specimens documented here.
Etymology. Named in honour of the late Martin Wijesinghe (1939–2021), in recognition of his conservation and education actions and advocacy, especially with respect to forest biota and ecosystems of southwestern Sri Lanka. For nomenclatural purposes, the species name is a noun in apposition.
Suggested vernacular name. Martinge thudulla (Sinhala); Maartinin nilakael pambu (Tamil); Martin’s rhinophis or Martin’s shieldtail (English).
Distribution, natural history, and conservation. As far as is known, R. martin sp. nov. is restricted to the southeastern part of the Rakwana Massif, where it occurs from 750 m to at least 820 m elevation (Fig. 2). The upper elevational limit based on known specimens is not clear because of imprecise locality data, but is less than 1,360 m, the peak of Gongala Mountain. The holotype and USNM paratypes and USNM referred specimens were collected more than 40 years ago. The available field collection data do not indicate whether these USNM specimens were found in forest or in agricultural habitats, both of which occur in the general area today. The more-recently collected paratype specimens from Deniyaya were found when unearthed by mechanical diggers clearing an area of tea plantation for a car park. The new species is likely to qualify for Data Deficient status under IUCN Red List criteria (IUCN Species Survival Commission 2012), at least until new field surveys are undertaken to better clarify its range and any potential threats, and/or until additional specimens can be found in other collections.
Superficially similar Rhinophis specimens have been seen (LJMW, pers. obs.) but not collected ca. 15 km to the South of the type locality of R. martin sp. nov., at Rammale (ca. 6.25° N, 80.64° E; peak up to ca. 800 m), and ca. 25 km to the West of the type locality, at Dorana Ella (6.43° N, 80.42° E), Waddagala (6.46° N, 80.43° E), Lankagama (6.38° N, 80.45° E), and Mederipitiya (6.35° N, 80.49° E). These places are indicated on the map in Fig. 2. However, detailed comparisons have not yet been made, and the identities of those populations remain as yet unclear.
Remarks. Sampaio et al. (2023) included DNA sequences for three specimens of R. martin sp. nov. in their phylogenetic analyses, labelled as “ Rhinophis sp. (Deniyaya)”. There are no morphological vouchers for those specimens; these sequences were obtained from tissues of parts of three different and partial animals that were found alongside the three complete paratype specimens collected in 2018. Sampaio et al. ’s (2023) analyses recovered (with maximal support) R. martin sp. nov. as most-closely related to R. tricoloratus among sampled taxa, with these two species in a maximally supported clade with Rhinophis sp. (from Palabaddala), R. homolepis, and R. cf. mendisi. The Palabaddala specimen differs from R. martin sp. nov. in having a longer rostral shield, and a dark dorsum and pale venter. The material identified as R. cf. mendisi by Gower (2020) is from Rakwana (not far from the known localities of the new species: Fig. 2) but differs from R. martin sp. nov. in that it has a darker dorsum than venter, and a more crest-like dorsal ridge on the rostral shield. The three specimens of R. martin sp. nov. sampled by Sampaio et al. (2023) have identical DNA sequences, which differ notably from those of their closest-known relatives (Table 3). These three specimens of R. martin sp. nov. were inferred to be distinct from all other sampled taxa at the species level in all of the species delimitation analyses reported by Sampaio et al. (2023).
description: Published as part of Gower, David J., Sampaio, Filipa L., Vidanapathirana, Dulan Ranga & Mendis Wickramasinghe, L. J., 2024, Two new species of the shieldtail snake genus Rhinophis Hemprich, 1820 (Serpentes: Uropeltidae), from the Rakwana and the Knuckles Massifs of Sri Lanka, pp. 332-360 in Zootaxa 5458 (3) on pages 333-343, DOI: 10.11646/zootaxa.5458.3.2, http://zenodo.org/record/11547469