Asthenodipsas vertebralis
Creators: name: Quah, Evan S. H.
name: Lim, Kelvin K. P.
name: Grismer, L. Lee
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Reptilia
Squamata
Pareatidae
Asthenodipsas
Asthenodipsas vertebralis

description: Asthenodipsas vertebralis (Boulenger, 1900)
(Figs. 3, 4 & 5; Table 2 & 3)
Referred specimen. ZRC 2.6619, collected by Indraneil Das on 12 May 2002 from Gunung Berumput, Sarawak, East Malaysia.
Description of specimen ZRC 2.6619. Adult male SVL 502 mm and TaL 114 mm; rostral slightly wider than tall; head bulbous, longer than wide (HL/HW 1.97); nasals undivided; internasals shorter than prefrontals; posterior margin of prefrontals contact eye; frontal hexagonal, longer than wide; loreals present, 1/1, longer than tall; supraoculars subpentagonal, approximately 2/3 the length and half the width of frontal; preoculars absent; upper and lower postoculars present on both left and right side, lower postocular extending to below orbit; suboculars absent; supralabials 7/7 with 3 rd & 4 th contacting orbit and 7th elongate; temporals 2+2+2/2+2+2 (Fig. 4F); mental triangular, wider than long; anterior inframaxillary pentagonal, in contact with 1 st and 2 nd pair of infralabials; three pairs of posterior inframaxillaries following anterior inframaxillary, first pair of posterior inframaxillaries slightly oval, rhomboid-shaped, second and third pair square to hexagonal; infralabials 6/7 with 1 st pair in medial contact (Fig. 5D). Body long, slender, laterally compressed, bearing a prominent keel-shaped vertebral region; dorsal scales smooth, in 15/15/15 rows, vertebrals greatly enlarged; 190 ventrals; 68 divided subcaudals; cloacal scute entire; tail tapering to a point.
Colouration in preservation (Fig. 3). The ground colour of the head, body and tail is dark-brown with a series of approximately 40 black, poorly defined, rhomboidal bands ranging from 1–3 dorsal scales in length running along the dorsum from the nape to the base of the tail. The tail is irregularly mottled with dark spots. The supralabials, chin and throat are light-yellow with some fine speckling along the edges of the supralabials, mental, infralabials and inframaxillaries. The venter is yellowish cream with dark speckling along the lateral edges. A series of dark lateral spots are spaced along the belly, and are formed from the dorsal bands meeting the ventral scales. A thin, broken, light-yellow vertebral stripe is present.
Distribution in Borneo. Asthenodipsas vertebralis is currently only known from Gunung Berumput, Sarawak.
Comparison and comments on taxonomy. Asthenodipsas vertebralis, ZRC 2.6619 can be differentiated from A. laevis, A. borneensis, A. malaccana, A. jamilinaisi and A. stuebingi by its higher number of ventrals (190 vs. 148–179), higher number of subcaudals (68 vs. 26–53), and the pairs of infralabials in contact (1 st vs. 2 nd or 3 rd). It can be further separated from A. laevis by its number of dorsal scale rows (15/15/15 vs. 15/15/13) and the sharp vertebral keel (present vs. absent) (Quah et al. 2019, 2020). ZRC 2.6619 can also be differentiated from A. ingeri sp. nov. by the pairs of infralabials in contact (1 st vs. 1 st & 3 rd), the number of supralabials in contact with the orbit (3 & 4 vs 3–5) and more pairs of posterior inframaxillaries (three vs two).
ZRC 2.6619 is identified as A. vertebralis by its possession of three pairs of posterior inframaxillaries, first pair of infralabials in medial contact, yellowish labials and ventrals, and a banded dorsal pattern on the body with a thin, light vertebral stripe (Loredo et al. 2013). Its colour pattern rules it out as being A. lasgalenensis whose adult colour pattern consists of a solid, dark-brown to black dorsum with white labials and venter. It is further distinguished from A. tropidonotus by its lower number of subcaudals (68 vs. 73–76) and higher number of postoculars (2 vs. 1) and falls within the range of other scale and meristic characters reported for A. vertebralis (Table 3; Grossmann & Tillack, 2003; Loredo et al., 2013). However, in light of the resurrection of A. tropidonotus from the synonymy of A. vertebralis with the inclusion of genetic data, we only tentatively assign the specimen as A. vertebralis pending molecular analyses of specimens from Borneo.
description: Published as part of Quah, Evan S. H., Lim, Kelvin K. P. & Grismer, L. Lee, 2021, On the taxonomic status of Asthenodipsas vertebralis (Boulenger, 1900) (Squamata Pareidae) in Borneo with the description of a new species, pp. 24-44 in Zootaxa 4949 (1) on page 33, DOI: 10.11646/zootaxa.4949.1.2, http://zenodo.org/record/4677338