Afrotyphlops nanus, Broadley & Wallach, 2009

Broadley, Donald G. & Wallach, Van, 2009, 2255, Zootaxa 2255, pp. 1-100 : 32-33

Afrotyphlops nanus sp. nov.

( Fig. 5A)

Kenyan dwarf blind-snake

Holotype. BMNH 1897.11 .17.16, an adult male from Samburu, Coast Province , southeastern Kenya (39°17’S, 3°47’E, elevation 295 m). Collected by C. Stuart Betton during construction of the Uganda Railway about 1896.

Paratype. BMNH 1897.11 .17.17, an adult male with the same data as the holotype .

Diagnosis. Superficially resembling Afrotyphlops angolensis , this small species differs externally in its oval rostral with pointed apex (round or sagittate with rounded or truncated apex in A. angolensis ), low number of middorsals (287–291 vs 350–535 in East African A. angolensis ) and light venter.

Description (data on paratype in parentheses). Snout-vent length 122 (115.5) mm, tail length 3 (2.5) mm, total length 125 (118) mm, midbody diameter 5.5 (4.4) mm, mid-tail width 3.8 (3.0) mm, tail/total length ratio 2.4% (2.1%), tail length/tail width ratio 0.8. Head wider than body, snout profile tapered in dorsal view, bluntly wedge-shaped in lateral view, dorsal rostral oval with pointed posterior apex, 0.6 X head diameter, ventral rostral broad and V-shaped, frontal hexagonal, supraoculars oblique, wedged between preocular and ocular on left, but not meeting preocular on right (ocular making narrow contact with nasal), parietals transverse, enlarged to width of four scales, no enlarged occipitals (all scales posterior to parietals small). Nasal shield semdivided, superior nasal suture horizontal and approximately 50% of nostril-rostral gap, inferior nasal suture contacting first supralabial, nasal lacking postnasal concavity, one preocular—narrower than ocular (?), large eye entirely beneath ocular shield, postoculars 3 on left, 2 on right, four supralabials, SIP T-X (N2, P, O, O). Apical spine small and thin.

MSR 32-30-24 (30-30-26); MD 284–290 (mean 287.0, n = 2); SC 10–11 (mean 10.5, n = 2); L/D ratio 23–27 (mean 24.8, n = 2). Dorsum with zig-zag brown stripes formed from pigmented outer edges of 15 middorsal and lateral scales rows. These stripes are thickest and darkest middorsally and gradually narrow and weakened laterally. Background colour of dorsum and venter light creamy-yellow. Snout yellow, with stripes commencing on nape. Venter immaculate. Largest specimen (BMNH 1897.11.17.16— Samburu) has a total length of 125 mm.

Etymology. The trivial name nanus (Latin = dwarf) indicates that this may be the smallest species in the genus.

Distribution. Known only from the type locality in southeastern Kenya, 295 m ( Fig. 12).

Habitat. Acacia-Commiphora deciduous bushland and thicket.

Locality. KENYA. Samburu BMNH 1897.11.17.16–17 (holotype and paratype of Afrotyphlops nanus sp. nov.) .

Viscera. See Tables 9–11 for comparisons of visceral differences between Afrotyphlops nanus and other Afrotyphlops .