Aspidura ravanai, Mendis Wickramasinghe & Vidanapathirana & Dushantha Kandambi & Pyron & Wickramasinghe, 2017
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publication ID |
https://doi.org/ 10.11646/zootaxa.4347.2.4 |
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publication LSID |
lsid:zoobank.org:pub:1968CE67-0C8F-44C9-A12E-BD2196C9710C |
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DOI |
https://doi.org/10.5281/zenodo.5675633 |
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persistent identifier |
https://treatment.plazi.org/id/0D3187BE-2E21-FFC0-C58A-5AD056FBFB59 |
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treatment provided by |
Plazi |
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scientific name |
Aspidura ravanai |
| status |
sp. nov. |
Aspidura ravanai sp. nov.
Aspidura sp. Pyron et al. 2013
Holotype. NMSL-NH 2017.19.01 ( Figure 3 View FIGURE 3 ), adult male, 256 mm SVL, from Sri Pada upper region , Ratnapura district, Sabaragamuwa province, Sri Lanka, (06°48'28''N, 080°29'23''E, elevation 1,680 m a.s.l.): Coll. L.J.M. Wickramasinghe, D.R. Vidanapathirana, S.C. Ariyarathne, A.W.A. Chanaka, D. Kandambi and M.D.G. Rajeev on 05 February 2010. GoogleMaps
Paratypes. DWC 2017.05.01 ( Figure 4A View FIGURE 4 ), adult female 414 mm SVL ; DWC 2017.05.0 2 ( Figure 4B View FIGURE 4 ), adult male 218 mm SVL. Collection data as for the holotype GoogleMaps .
Diagnosis. Maximum adult SVL 218–414 mm; snout to eye distance 0.3 times the head length (SE/HL); prefrontals touching eye; preocular small, does not touch supraocular; postoculars 2, lower one larger than the upper; temporal 1+2/1+2; supralabials 6/6, 4th touching eye; infralabials 6/6, first pair in contact, progressively increasing in size from 1 st to 6th; anterior chin shields 2, large, touching 1–4 infralabials; posterior chin shields 2, anterior half in contact while the posterior half separated by 1st ventral; ventrals 132–139; subcaudals 20–29; dorsal scale rows 15–15–15 ; ischiadic, anal and tail base regions in the adults of both sexes keeled, with 1–3 peaks on each scale, more pronounced in males, spinose tubercles absent ( Figures 5 View FIGURE 5 ); entire dorsum jet black; bright yellow line from base of tail to tail end; venter black with bright yellow blotching all over.
Description of holotype. Adult male; SVL 256 mm; TaL 37.2 mm; TL 293.2 mm; TaL/TL 0.13; body elongate and cylindrical; head short (SVL/HL 20), elliptical, indistinct from thick neck; snout long, narrowing anteriorly, pointed in dorsal aspect, snout to nostril distance about 2.3 (EW/SN) times as long as nostril width; nasal divided; small, triangular nostril, touching divided nasal and first supralabial, not touching rostral; eye larger than horizontal diameter of nostril, eye width about 0.3 (EW/SE) times the distance between snout to eye, round pupil; snout to eye distance 0.3 times head length (SE/HL); tail short (TaL/SVL 0.15), robust at its base, tapering progressively to a single point.
Head scalation. Head scalation including 1 internasals, 2 prefrontals, 2 supraoculars, 1 frontal, and 2 parietals. Rostral small, convex, wider than long and truncate in dorsal aspect, projecting ventrally. Nasal vertically divided by a groove above nostril. Internasal single, large, irregular hexagonal; widely in contact with prefrontals. Two large prefrontals, longer and wider than internasal, largest distance along the longitudinal axis of prefrontals shorter than frontal in length, anterior-most corner of prefrontals touching nasal, bordered by 2nd and 3rd supralabial, preocular scale, eye, supraocular and frontal. Preocular small, not in contact with supraocular. Loreal and subocular scales absent. Supraocular smaller than frontal. Two postoculars, lower one larger than upper. Two parietals; largest scales on head. Temporals 1+2/1+2. Supralabials 6/6, 4th touching eye, progressively increasing in size from 1st to 6th. Mental small and triangular, wider than long. Infralabials 6/6, first pair in contact, progressively increasing in size from 1st to 6th. Anterior chin shields 2, large, touching 1–4 infralabials. Posterior chin shields 2, anterior half in contact, posterior portion separated by 1st ventral.
Body scalation. Ventrals 139, 1st ventral longer than wide; subcaudals 29, all single; anal single and large; dorsal scale rows 15–15–15; coastal scales on posterior body from about 110th ventral feebly keeled, except the ischiadic region which is coarsely keeled, with 1–3 peaks on each scale; vertebral rows and first coastal not enlarged; Colour in life. Entire dorsum jet black. Fourth supralabial to neck displays bright yellow stripe ventrolaterally. Irregular bright yellow stripe continues ventrolaterally from neck to tail, becoming discontinuous midbody. Venter black with bright yellow blotching all over; gular region primarily bright yellow.
Colour in alcohol. Colour pattern remains unchanged. Pupil changes to off white. Black colour fades, bright yellow changes to off white.
Variation. Female paratype showed much weaker keeling on coastal scales. The first ventral wider than long. Subcaudals 20, the first subcaudal divided. Snout truncate in dorsal aspect. Male paratype showed ventrolateral bright yellow stripe only on the head and tail regions. In both paratypes, gular region black with very little bright yellow blotching.
Hemipenis morphology. Based on DWC 2017.05.0 2 paratype specimen: right everted hemipenis extends for length of 5 subcaudals. Everted organ single subcylindrical, sulcus spermaticus simple. Basal to apex region bearing prominent spines which are evenly distributed and are in uniform length ( Figure 6 View FIGURE 6 ).
Natural History. Seventeen specimens of Aspidura ravanai have been found in montane cloud forests between 1,650–2,000 m elevation. Mostly found in shady areas with dense leaf litter, hidden under loose soil or logs, and can be found up to about 30 cm below ground level.
Etymology. The specific epithet ravanai is formed after Emperor Ravana, one of the greatest Emperors of all times, who is believed to have lived nearly 5000 years ago in Sri Lanka, and was said to have had immense intelligence and power. The name ravanai is a noun in the genitive case.
Suggested common names. Ravanage madilla, and Ravana’s rough-side snake in native Sinhala and English respectively.
Molecular divergence. The results from our dating analysis suggest that Natricinae began diversifying approximately 37 Ma (95% Highest Posterior Density [HPD] = 29–45, Ma) in the late Eocene, consistent with most previous studies (e.g., Guo et al. 2012; Chen et al. 2013). The genus Aspidura began diversifying in the early Miocene, ~18 Ma (95% HPD = 13–24 Ma), and A. ravanai diverged from A. trachyprocta in the late Miocene, ~6.2 Ma (95% HPD = 2.8–10.0 Ma). Thus, there is substantial evolutionary and genetic divergence between these taxa, despite their general morphological similarity and ecological sympatry ( Figure 2 View FIGURE 2 ).
Comparison. The new species was compared with all known congeners of the genus Aspidura and the species most closely resembles A. trachyprocta ( Figure 7 View FIGURE 7 ) due to the following combination of characters: Similar body size, one preocular, two postoculars, 1+2 temporals, supralabials 6, 4th supralabial in contact with the eye, infralabials 6 ( Figure 7B View FIGURE 7 ), coastals 15 , single cloacal scale, overlapping ventral and subcaudal counts, and similar habitat preferences, but can easily be distinguished from the following morphological characters: (1) entire dorsum jet black in Aspidura ravanai by (vs. reddish-yellow to brown with a longitudinal black stripe on mid dorsum in Aspidura trachyprocta ) ( Figure 7–8 View FIGURE 7 View FIGURE 8 ), (2) ventrolaterally an irregular longitudinal yellow stripe (vs. black stripe), (3) spinose tubercles absent (vs. spinose tubercles present, more pronounced in males) ( Figure 9–11 View FIGURE 9 View FIGURE 10 View FIGURE 11 ), (4) hemipenis extends for length of 5 subcaudals (vs. 3–4), narrow apex (vs. broader), ridges absent (vs. present) ( Figure 6 View FIGURE 6 ); from A. brachyorrhos by having 15 coastals (vs. 17), preocular not in contact with supraocular (vs. contact), prefrontal contact with eye (vs. separate), single subcaudals (vs. paired); from A. copei by having coastals 15 (vs. 17), single subcaudals (vs. paired), single preocular (vs. absent); from A. deraniyagalae by larger SVL 218– 414 mm (vs. small SVL 90–126), coastals 15 (vs. 17), ventrals 132–139 (vs. 117–122), single subcaudals (vs. paired); from A. drummondhayi by having single subcaudals (vs. paired), single preocular (vs. absent); from A. guentheri from larger SVL 218–414 mm (vs. small, SVL 170 mm), coastals 15 (vs. 17), ventrals 132–139 (vs. 100– 127); from A. ceylonensis by prefrontal touching eye (vs. not touching eye), preocular does not touch supraocular (vs. touches), lower postocular larger than the upper (vs. vise versa), mid body coastals not keeled (vs. coarsely keeled).
| DWC |
DWC |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
