Rhinophis dorsimaculatus Deraniyagala 1941
Creators: name: Gower, David J.
name: Mendis Wickramasinghe, L. J.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Squamata
Uropeltidae
Rhinophis
Rhinophis dorsimaculatus

description: Rhinophis dorsimaculatus Deraniyagala, 1941
Rhinophis dorsimaculatus Deraniyagala, 1941: Deraniyagala (1941: 800–802, fig. 1, plate 1); Smith (1943: 88, 526); Taylor (1950: 533); Deraniyagala (1955: 12, 15, plate 36); Gans (1966: 13–14); de Silva (1980: 113, 131, 183, 190, 191, 195); Mahendra (1984: 63, 65); de Sliva (1990: 45, 69); Cadle et al. (1990); de Silva (1996: 70); de Silva (1998: 111); McDiarmid et al. (1999: 136); Abeysiriwardana et al. (2000: 195); Bambaradeniya & Samarasekara (2001: 36); de Silva (2001: 63); Bossuyt et al. (2004: fig. 2C); Somaweera (2006: 227, 234, 235) (in part); Wickramasinghe et al. (2009: 1, 6, 11) (in part); Gower & Maduwage (2011: 55, 59, 60, 63, 65); Pyron et al. (2013: 977, fig. 1); Wallach et al. (2014: 638).
Holotype. The “ type ” designated by Deraniyagala (1941). NMSL 86, collected 1938 or 1941 from “the coastal village of Marichchukate [= Marichchikattuwa; Marichchukkaddi], North Western Province, Ceylon [= Sri Lanka]”, now lost (Gans, 1966: 14). Approximate coordinates from maps: 8º 35’ N, 79º 57’ E, <40 m elevation.
“Paratype”. NMSL unnumbered, collected 1938 or 1941 from the type locality. In his description of the species, Deraniyagala (1941) mentioned a second specimen. However, he did not explicitly designate it as a type or report a specimen number. There is no evidence that any of the data or figures reported for R. dorsimaculatus pertain to this second specimen, which we thus do not consider a paratype. The second specimen, which is also lost (Gans 1966: 14), was referred to as a paratype by Gans (1966: 13).
Referred material. Ten specimens, all from the type locality, newly referred here. CAS 225802, 225803 and 225804 (collected 27 November, 1974), 225842 and 225843 (29 April, 1976), 226077 and 226078 (9 February, 1977), 226662 (29 May, 1974), and 244583 and 244584 (4 December, 1974). These specimens were in the personal collection of, and under tight proprietary control by, Carl Gans until they were donated to the CAS shortly before his death (C.J. Bell pers. comm. 2016). The CAS material is referable to Rhinophis dorsimaculatus on account of it being topotypic, and matching the holotype in its long and dorsally carinate rostral, large posteriormost ventral projecting between the posterior margins of the anal scales, high number of ventrals (227+), and distinctive colour pattern with a highly regularly punctate flanks and belly and approximately midvertebral, somewhat irregular black blotches lying in a broad, pale, middorsal stripe.
Revised diagnosis. In having 227 or more ventral scales, R. dorsimaculatus differs from all congeners except R. punctatus Müller, 1832 and R. porrectus Wall, 1921. Rhinophis dorsimaculatus differs from R. porrectus in having fewer than 260 (227–250 among the only known material) versus more than 260 ventral scales (283 in holotype of R. porrectus). Rhinophis dorsimaculatus differs from R. punctactus in its colour pattern. Although both species have a broad pale dorsal stripe, in the former this bears dark dorsal blotches and in the latter a continuous narrow dark vertebral line. Additionally, the colour of R. punctatus resembles that of R. porrectus in that the pale dorsal stripe is bordered by a broad dark, dorsolateral stripe (broader than the dark lines on the lower flanks and belly), whereas in R. dorsimaculatus the pale stripe is bordered by a narrow dark line that is undifferentiated from the similar lines on the lower flanks and belly.
Rhinophis dorsimaculatus also differs clearly from the non- Rhinophis Sri Lankan uropeltids that, although currently classified in other genera (Pseudotyphlops, Uropeltis, e.g., McDiarmid et al., 1999), likely form part of the Sri Lankan uropeltid radiation together with Sri Lankan Rhinophis (Cadle et al. 1990; Bossuyt et al. 2004; Pyron et al. 2013). Thus, R. dorsimaculatus differs (beyond in its distinctive colour pattern) from Pseudotyohlops philippinus Müller, 1832, Uropeltis phillipsi (Nicholls, 1929) and U. melanogaster (Gray, 1858) in having far more than 170 ventrals and a strongly dorsally carinate rostral. The same differences apply to U. ruhunae Deraniyagala, 1954, known from a single specimen that otherwise bears features found only among some Indian uropeltids.
Description of referred specimen CAS 225842. Generally good condition; split ventrolaterally and ventrally at vent. Head small; snout pointed. Rostral large, protruding far anterior (1.8 mm) to mouth, pointed, trihedral anteriorly, much longer than wide, dorsally strongly carinate and raised/arched (in lateral view); rostral widest at level of anterior superior corner of first supralabials. Rostral many times longer (in dorsal view) than short rostralfrontal gap. Frontal subtriangular with convex anterior margin, distinctly longer than wide, little break in angle between anterolateral (ocular) and posterolateral (parietal) margins. Frontal much shorter than, as wide as, rostral. Paired nasals (and most of prefrontals) separated from each other by rostral. External naris small, subcircular, slightly countersunk within small depression, located in anteroventral corner of nasal. Nasal contacts supralabials 1 and 2. Prefrontals briefly (for less than 25% of their length) in contact with each other along midline, briefly separating frontal from rostral. Prefrontals taller than long, longer than frontal. Supralabials four, first smallest, making the least contribution to margin of mouth; second larger but only slightly longer at mouth; fourth much the largest. Ocular contacts supralabials 3 and 4. Eye small but distinct, diameter less than one third length of ocular, located near anteroventral corner of ocular, bulging slightly from ocular surface, pupil subcircular. Paired parietals longer than frontal, broadly rounded posteriorly (a little> 90°). Opposite parietals in brief midline contact, left overlapping right. Parietals a little longer than wide, wider than frontal and rostral. Each parietal contacts four scales other than head shields and supralabials. Three infralabials, first and third subequal in length, notably shorter than second. First infralabials not in midline contact behind mental. First ventral longer than wide, second to fourth approximately as long as wide, fifth and subsequent ventrals wider than long. First ventral not in contact with mental.
Seven maxillary and seven or eight mandibular teeth on each side. Teeth simple, pointed, distinctly retrorse, straight, evenly spaced. Anteriormost maxillary tooth aligned approximately with posterior end of lower margin of second supralabial, posteriormost maxillary tooth close to posterior edge of lower margin of third supralabial; mandibular row similar in length and alignment, with anteriormost member a little further forward than maxillary row. Inside of mouth, including tongue, unpigmented.
Body subcylindrical to slightly dorsoventrally compressed. Head and body scales macroscopically smooth, lacking keels. Body scales generally evenly sized on dorsum and along body. Midline ventral scales between mental and anal of even size though anterior- and posteriormost ones gradually narrow. Posteriormost ventral much larger, V-shaped, separating posterior margins of paired anals. Right anal possibly slightly overlaps left, but overlap almost entirely absent. Ventrals 230, at midbody same width as exposed part of adjacent first dorsal scale row. Posteriormost three or four ventrals slightly wider, 1.05 times as wide as adjacent first dorsal row; final ventral much wider, V-shaped, 1.5 times as wide as first dorsal row. Dorsal scale rows 19 anteriorly, reducing to 17 along most of body, until slightly anterior of vent. Scale row formula:
4+5 (11) 3+4 (224)
19 ------------------- 17 ------------------- 15
4+5 (11) 3+4 (225)
Dorsal scale rows approximately 13 at base of tail. Paired anal scales slightly larger than posteriormost dorsal scales and subcaudals, slightly smaller than last ventral; only briefly in midline contact, substantially overlapped by last ventral. Distal margin of each anal overlaps three other scales in addition to anteriormost subcaudals. Subcaudals 7 (left), 8 (right), either all paired/divided with posteriormost on right much wider than others, or under an alternative interpretation posteriormost subcaudals all single/undivided. Tail scales macroscopically smooth though many with two or three inconspicuous, low keels on posterior portion of posteriormost subcaudals on lower flanks. Caudal 'shield' bluntly conical, forming tip of tail, longer than wide in dorsal view, only slightly shorter than shielded part of head, more visible from above than below, base (only a littler narrower than base of tail) surrounded by last pair of subcaudals and 10 other scales. In posterior view shield regular broad oval, widest point approximately mid height. Shield surface matt, covered with tiny tubercles in approximately radial distribution. Narrow halo around base of shield glossy and without tubercles.
Left hemipenis everted, perhaps not fully. Moderately long (ca. 4.8 mm), slender, subcylindrical, slightly tapering distally. Asulcate surface ornamented with short, slender, curved, proximally-directed, evenly spaced spines extending to base of organ. Sulcate surface mostly lacking spines or other ornamentation, more encroachment of spines towards sulcus margins distally than proximally. Sulcus spermaticus shallow, inconspicuous, walls smooth.
In alcohol, background body colour pale tan with much darker (brown to blackish) markings. Broad, regular, pale middorsal stripe/band across five scale rows extending from shortly behind head to tail shield. Pale middorsal band marked with asymmetrical dark blotches, mostly discontinuous, more continuous anteriorly, darker posteriorly, becoming blackish on tail. All other dorsal scale rows of body and all ventrals each with single dark dot together forming series of regular, narrow, punctate lines along length of body. Dark spots on body scales confined to scale bases, distal margins paler and translucent. Tail with more unmarked scales laterally and ventrolaterally than on body. Anals coloured as posteriormost ventrals and dorsal scales of lower flanks. Tail shield matt, mostly pale orange with broad, irregular, subterminal pale brown ring. Head brownish grey with small pale flecks, pale borders to many shields. Rostral somewhat yellowish, paler anteriorly and ventrally. Posteromedial parts of parietals pale. Edges of mouth (‘lips’) paler than dorsal and ventral surface of head.
Variation. See Table 1 for meristic and morphometric details. CAS 225843 and 226077 (the latter with much of inside of mouth blackish, this atypical condition possibly artefactual) in generally good condition; other CAS specimens dehydrated or otherwise damaged. CAS 225804 incomplete, in several parts, and poorly preserved; CAS 244583 eviscerated, largely skinned and missing anterior of head; CAS 244584 partly eviscerated and lacking most of vertebral column, end of tail including shield missing. CAS 225842 and the other new specimens closely match the lost holotype. The holotype was seemingly less attenuate than the best-preserved CAS specimens (Table 1). The number and disposition of head shields (including left over right overlap of parietals) is similar in all specimens as far as can be ascertained. Mental notably more prominent in CAS 225843 and separated from anteriormost chin shields (as also in CAS 226078) by midline contact between first pair of infralabials.
Ventrals 230 – 250; subcaudals 6 to 8 on each side. In some specimens (e.g., CAS 225843) it is difficult to determine whether some of the posteriormost scales on the ventral surface of the tail are ‘true’ subcaudals or not. Anals always paired, making little or no midline contact except slight right over left overlap in CAS 226662. Dorsal scale rows always 19 anteriorly, 17 by level of 13th ventral and then without reductions until close to the vent (see Appendix). Tail shield slightly variable in shape and size, for example it is more squarely-ended and strongly overhangs the posteriormost subcaudal in CAS 225843 and, to a lesser extent, in 226077. The shield tubercles are all small but vary from being low and worn (e.g., CAS 225842, 226662) to more prominent, pointed and spine-like (e.g., CAS 225843).
Colour pattern generally constant and matching holotype (as figured by Deraniyagala 1941). Posteromedial edges of parietals generally pale (as in holotype and CAS 225842), pigmented in CAS 225843. Tail shield always somewhat orange, but brown marks more or less diffuse and variable in shape (e.g., U- rather than O-shaped in CAS 226662). Pale dorsal band on body always present but variable. For example, it is three (rather than five) scales wide on the anterior half of CAS 226662 and anterior two thirds to three quarters of CAS 225843, 226077, and 244584. The narrow, punctate, darker lines on the other dorsal scale rows and ventrals are a constant feature. Last ventral unpigmented in CAS 225843, 226077, 226662, and 244584.
Suggested ‘common’ names: Blotched Rhinophis, Marichchukate Rhinophis (English). The names ‘orange shield tail’ (English) and ‘thambapanni walga ebaya’ (Sinhalese) were used by Wickramasinghe (2012: 112).
Distribution, natural history, and conservation: The lost types and only known existing museum specimens of Rhinophis dorsimaculatus are all from a single locality, Marichchukate, on the northwestern coast of Sri Lanka (Fig. 3). This is lowland and in the dry zone (sensu Legg & Jewell 1995), in contrast to most Sri Lankan uropeltids that occur in the hills of the wet zone. We here report a second locality for R. dorsimaculatus. On 21 and 23 January 2014, eight live R. dorsimaculatus were seen at Sannar near Vidattalativu, Northern Province (8º 59’ 30.69” N, 80º 06’ 26.34” E, <20 m elevation) while digging in loose soil and/or on the surface at night following monsoon rainfall. This locality is also northwestern coast dry zone lowland, approximately 40 km north of the type locality (Fig. 3). The habitat was typical dry-zone evergreen forest mixed with shady home garden vegetation. None of the animals was collected but two were photographed (Fig. 4). Data were not recorded for the two photographed animals but their colour pattern, head shields, and vertebral scale counts (235 and 238) closely match those of the lost holotype and the CAS specimens of R. dorsimaculatus reported here. One of the photographed specimens (Fig. 4, left panel) has a more orange dorsal band (as reported for the type material by Deraniyagala 1941, 1955) and the other (Fig. 4, right panel) a paler tan band. Both specimens differ slightly from the CAS specimens in that the dark dorsal blotches are more continuous and less asymmetric, and the pale band has more scales with dark marks.
The type and the newly reported locality were, until recently, inaccessible during three decades of civil unrest in Northern Province. After the war (itself cited as a cause of habitat degradation by Abeysiriwardana et al. 2000), the region has experienced rapid deforestation for human settlement. Much of the forest cover in the region of Marichchukate has been cleared. In addition to expanding human settlements, forest has been cleared for agriculture, which might also pose a conservation threat to R. dorsimaculatus (see also Abeysiriwardana et al. 2000). The second author and colleagues have also seen roadkill specimens of R. dorsimaculatus in the region.
description: Published as part of Gower, David J. & Mendis Wickramasinghe, L. J., 2016, Recharacterization of Rhinophis dorsimaculatus Deraniyagala, 1941 (Serpentes: Uropeltidae), including description of new material, pp. 203-212 in Zootaxa 4158 (2) on pages 204-209, DOI: 10.11646/zootaxa.4158.2.3, http://zenodo.org/record/272212