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Neelaps Günther, 1863

Type species. Furina calonotos (= Neelaps calonotos) Duméril, Bibron & Duméril, 1854a: 1241, by monotypy.


Etymology. Günther (1863: 24) provided no derivation of name, but it is presumably from the Greek neos meaning new and Elaps the type genus of the family Elapidae.

Revised diagnosis. A monotypic genus comprising N. calonotos, a very small, slender fossorial hydrophiine elapid snake (total length to 271 mm this study, males mean 239 mm, females mean 220 mm, tail length 10.4‒18.9% of SVL mean 15.2%) with: head narrow, depressed and not distinct from neck; protrusive round-shaped snout without cutting edge; no canthus rostralis; frontal not much wider than long; internasals present slightly smaller than prefrontals, suture between internasal and prefrontal transverse; preocular in contact with nasal, rarely separated by prefrontal; typically upper primary and secondary temporals fused to form single elongate scale without deep ventral descent (Fig. 3B), occasionally 1 + 1; rostral much wider than high posteriorly obtuse and only slightly projecting between internasals; a consistent colour pattern of dark crescent-shaped band extends across nape and dark broad band across head forward to level of eyes; tip of snout consistently dark; variable body colour of bright, pale pinkish or orange red with pale anterior portion or spot on each scale, typically distinct feature of a dark vertebral stripe with pale anterior portion or spot forming chain-like pattern extends from nape to tip of tail; 124‒145 ventrals; 128‒148 vertebrals; midbody scales very glossy and smooth, in 15 rows occasionally increasing to 16 posterior to the head and decreasing to 14 or 13 anterior to the vent; anal and 23‒34 subcaudals divided; supralabials six, last the largest; infralabials seven; ventral surface white with glossy shine; eyes are small with pupils indiscernible within black irises (Bush 2017). Other features in the genus are the reversion to the primitive karyotype of 2N = 36 (16M and 20m) (Mengden 1985), and pterygoid tooth row reduced posteriorly such that it does not extend beyond the level of the ectopterygoid-pterygoid articulation (Greer 1997). Storr (1968: 85) and B. Maryan record total lengths of 284 mm and 281 mm, respectively in female N. calonotos.

Based on phylogenetic affinities, Neelaps is compared with the other fossorial snake genus of Vermicella using Keogh & Smith 1996; Storr et al. 2002; Cogger 2014 and Wilson & Swan 2021.

Differs from Vermicella in: substantially smaller adult ToL to 271 mm (versus to 760 mm), lower ventral scale counts of 124‒145 (versus > 195), typically one elongate temporal scale (versus 1 + 1, but primary temporal occasionally fused with second last supralabial), protrusive round-shaped snout (versus bluntly round-shaped snout), preocular and nasal separated by prefrontal (versus preocular in contact with nasal, rarely separated by prefrontal), typically vertebral stripe present along the body, or if reduced some indications remain (versus encircled by bands along the body) and widely allopatric distributions. Additionally, Neelaps feed on small lizards and at most when threatened raise forebody and thrash, while most (probably all) Vermicella species feed entirely on blind snakes (Typhlopidae), contort their bodies into vertically oriented loops, thrash and re-position.