Leptotyphlops drewesi Wallach, 1996

Published, First, 2007, A revision of the genus Leptotyphlops in northeastern Africa and southwestern Arabia (Serpentes: Leptotyphlopidae), Zootaxa 1408, pp. 1-78 : 19

Leptotyphlops drewesi Wallach ( Plate 6 , Fig. 4)

Drewes’ worm snake

Leptotyphlops drewesi Wallach, 1996 , J. Afr. Zool. 110: 426, fig. 1. Type locality: northern base of Mount Kenya, 10 km south of Isiolo, Eastern Region, Kenya (0°21’N, 37°35’E, elevation ca. 1400 m), holotype CAS 85756, collected by R.E. Leach & E.S. Ross, 26 November 1957; McDiarmid et al., 1999: 28; Spawls et al., 2002: 301.

Diagnosis. A member of the Leptotyphlops reticulatus species group, differing from both other species in its small bulbous rostral, high middorsal count (248 vs 179–192 and 227–238 respectively) and colouration.

Description. Body cylindrical, with head and neck broadened and flattened, the short tail tapers abruptly to a large thorn-like apical spine, recurved ventrally.

Snout rounded, rostral narrow (0.33 head width) and short, subequal in width to nasals anteriorly, but slightly bulbous and protruding, not reaching interocular level posteriorly. Behind rostral, upper lip bordered by small infranasal (nostril midway between rostral and supralabial along nasal suture), moderate anterior supralabial that extends dorsally beyond level of the nostril with a width along lip twice that of infranasal, large ocular with a moderate eye with a distinct pupil near the upper anterior edge, and moderate posterior supralabial. Supraoculars pentagonal, anteriorly wedged between upper nasal and ocular, posteriorly wedged between a subequal hexagonal frontal and pentagonal postfrontal, interparietal absent, interoccipital much larger than the frontal and postfrontal. Parietals transverse, in contact with the posterior supralabials, subequal to the enlarged occipitals, which are in contact medially. Temporal single. No mental.

Body covered with 14 rows of smooth, imbricate scales, the vertebral row slightly enlarged, reduced to 10 rows on tail. Total middorsals 248, subcaudals 26.

Total length/diameter ratio 41; total length/tail length ratio 11.9.

Bicoloured, with five light brown middorsal scale rows, a midlateral lightly pigmented row and seven immaculate creamy-white ventral rows, a light nuchal collar (ca. 2 scales wide), broken on the vertebral line, lower snout and upper lip white.

Size. Length of holotype 131 + 12 = 143 mm, midbody diameter 3.5 mm.

Distribution. Only known from the type locality on the ecotone between the semi-arid steppe of the Somali Arid zone and the wooded and open grassland of northern Mount Kenya, 1400 m ( Plate 5 ). This consists of steep slopes with short grasses and scattered low thorn trees ( Acacia ).

Figures

PLATE 5. Leptotyphlops. Distribution of the Leptotyphlops parkeri, L. reticulatus, L. longicaudus and L. nigricans species groups in northeastern Africa and southwestern Arabia.

PLATE 6. Figure 1. Leptotyphlops parkeri. Dorsal and lateral views of the holotype, BMNH 1949.2.3.47 — Degeh Bur, Ethiopia. The line represents 1 mm to scale. After Broadley, 1999. Figure 2. Leptotyphlops reticulatus. Dorsal, lateral and ventral views of the head of the holotype, BMNH 1946.1.16.53 — Wagar, Golis Mts, Somalia. From Lanza, Snakes of Somalia (in prep.). Drawings by E. Wade. Figure 3. Leptotyphlops boulengeri. Dorsal. lateral and ventral views of the head of MCZ 40085 — Lamu Island, Kenya. The line represents 1 mm to scale. Figure 4. Leptotyphlops drewesi. Dorsal and lateral views of the head of the holotype, CAS 85756 — 10 km south of Isiolo, Kenya, after Wallach (1996). The line represents 1 mm to scale.