A new species of Rhinophis Hemprich, 1820 (Serpentes: Uropeltidae) from southwestern Sri Lanka

Abstract

A new species of the uropeltid snake genus Rhinophis Hemprich, 1820 is described from near Balangoda, southwestern Sri Lanka. Rhinophis mendisi sp. nov. superficially resembles R. homolepis (Hemprich, 1820) in colour pattern and in its prominent, conical tail shield, but differs from that species in having far fewer ventrals (159–177, n = 13 versus > 195 in the types of R. homolepis and its subjective junior synonym R. gerrardi). The five type specimens and one of the referred specimens of the new species were collected probably between 1894 and 1925, and the only known additional, referred specimens (n = 8) were collected from within ca. 30 km of the type locality in 1972. A lectotype is designated for Mitylia gerrardi Gray, 1858, a subjective junior synonym of R. homolepis.

A new Indian species of Rhinophis Hemprich, 1820 closely related to R. sanguineus Beddome, 1863 (Serpentes: Uropeltidae)

“…As in some other species of Rhinophis (e.g. Wickramasinghe et al 2017Wickramasinghe et al , 2020Gower 2020), including R. sanguineus (Wall 1919), females tend to have fewer subcaudals (and shorter tails) and more ventrals. The number of ventrals is broadly overlapping between the sexes, but the subcaudal counts are not, being a mean (of left and right counts) of 4-5 in females and 6.5-8 in males (Fig.…”

“…Pyron et al 2016). Eighteen of the 23 currently recognised species of Rhinophis are endemic to Sri Lanka, and no species occur in both Sri Lanka and India (Cyriac et al 2020;Pyron et al 2016;Wickramasinghe et al 2017;Gower 2020). Following the recent description of R. melanoleucus Cyriac, Narayanan, Sampaio, Umesh & Gower, 2020, there are five currently recognised Indian species of Rhinophis (Cyriac et al 2020).…”

Intraspecific morphological variation in the shieldtail snakeRhinophis philippinus(Serpentes: Uropeltidae), with particular reference to tail‐shield and cranial 3D geometric morphometrics

“…Tail length was used to infer sex of all specimens given that it was found to be strongly dimorphic (see below). Sex was determined for a few specimens by examination of the urogenital system via small incisions-as in the many other species of Rhinophis with dimorphic tail length Gower, 2020), longer and shorter tails were always found in males and females, respectively. Eight linear measurements were taken using dial calipers to the nearest 0.1mm: tail length, head length (snout tip to posterior of fourth supralabial), head width (at posterior ends of fourth supralabials), midbody width, tail-shield middorsal length (shortest distance between posterior tip and anterodorsal midline limit of shield), tailshield midventral length (shortest distance between posterior tip and anteroventral midline limit of shield), tail-shield height at base (shortest distance between anterodorsal and anteroventral midline limits of shield), tail-shield width at base (maximum transverse width of base of shield).…”

“…Sexual dimorphism has emerged as an important aspect of uropeltid biology that is open to investigation using static museum specimens, and which has implications for understanding other aspects of uropeltid natural history. Many, but not all, uropeltid species are sexually dimorphic in tail length and numbers of subcaudal scales (Boulenger, 1893;Constable, 1949;Gower, 2020;Gower et al, 2016;Guibé, 1948;Jins et al, 2018;Wall, 1919Wall, , 1921, and some are also sexually dimorphic in numbers of ventral scales (which correspond to the number of pre-caudal vertebrae (Alexander & Gans, 1966) and in the prominence of longitudinal ridges (keels) on scales under the tail and posterior end of the body Jins et al, 2018). Greater appreciation and analysis of these widespread sexual dimorphisms have had a substantial positive impact on taxonomic revision of uropeltids, and the de mieux comprendre la variation morphologique du crâne et des boucliers caudaux osseux de ces espèces, nous avons réalisé une étude intraspécifique sur 35 spécimens de Rhinophis philippinus.…”