Leptotyphlops monticolus (Chabanaud)

Published, First, 2007, A revision of the genus Leptotyphlops in northeastern Africa and southwestern Arabia (Serpentes: Leptotyphlopidae), Zootaxa 1408, pp. 1-78 : 35-37

Leptotyphlops monticolus (Chabanaud) ( Plate 10 , Fig. 1)

Virunga worm snake

Glauconia emini — Sternfeld, 1910: 12, 1912: 264; Witte, 1933: 84 (part, Kissenye).

Glauconia monticola Chabanaud, 1917 , Bull. Mus. Natn. Hist. Nat. Paris 22: 366, figs.7–9. Type locality: Volcans de Kivori , Congo-Belge [= E. Kivu Region, Democratic Republic of Congo], elevation 1500 m, holotype MNHN 1916.213 , collected by Gromier and Le Petit, 1911.

Leptotyphlops emini — Witte, 1941: 171; Broadley, 1998: xxix.

Leptotyphlops monticola — Witte, 1941: 172.

Leptotyphlops emini emini — Loveridge, 1941: 177 (part); Laurent: 1956: 81; Roux-Estève, 1975: 60.

Leptotyphlops nigricans nigricans — Hahn, 1980: 23 (part); McDiarmid et al., 1999: 39.

Diagnosis. A member of the Leptotyphlops nigricans species group, distinguished from neighbouring L. emini by its relatively higher middorsal counts.

Description. Body cylindrical, with head and neck broadened and flattened, the short tail tapers slightly before a short stout spine or a blunt tail cone.

Snout rounded, rostral broad (0.43–0.45 head width, mean = 0.44) and truncated posteriorly, much wider than supranasals dorsally and extending to a line connecting centre of eyes, a preoral groove present ventrally. Behind rostral, upper lip bordered by infranasal (nostril nearer rostral than supralabial along nasal suture), small anterior supralabial that reaches level of nostril with a width along lip 2.0–3.0 times that of the infranasal, large ocular with eye central in upper half, and tall posterior supralabial. Supraoculars pentagonal, slightly larger than the hexagonal frontal and postfrontal, which are slightly smaller than the interparietal and interoccipital. Parietals oblique, subequal to the fused occipitals, in contact with the posterior supralabials. Temporal single.

Body covered with 14 rows of smooth, imbricate, subequal scales. Reduction to 10 rows on the tail takes place lateral to the subtriangular cloacal shield. Total middorsals 204–247; subcaudals 21–31.

Total length/diameter ratio 44–77; total length/tail ratio 8.0–13.5.

Uniformly dark brown to black dorsum and venter.

Skull with fused parietal bones as in Leptotyphlops nigricans ( Plate 4 , Fig. 1A).

Size. Largest specimen 154 mm ( Roux-Estève, 1975).

Habitat. Montane grassland and gallery forest.

Distribution. The Virunga National Park and environs in the Kivu Province of the Democratic Republic of Congo and adjacent Rwanda, 900–1500 m ( Plate 5 ).

Localities. DEMOCRATIC REPUBLIC OF CONGO (KIVU). Parc National Virunga: Goma IRSNB 3103 , 6847 ; Kabiro IRSNB 12977 ; Katanda IRSNB 3100 ; Katare IRSNB 12970 (7) , NMZB 15309–11 ; “ Kivu volcanoes” NMHN 1916.213 (holotype) ; Mahia IRSNB 12974 (2) ; Nyamuli IRSNB 12973 ; Rutshuru IRSNB 3102 ; Rwindi IRSNB 5369 , 12985 ; Tshanzerwa IRSNB 3101 ; Vitshumbi IRSNB 6848 . RWANDA. Kisenyi MCZ 42898 ; ZMB 27155 .

Figures

PLATE 4. Figure 1. Dorsal views of the skulls of Leptotyphlops. A. Leptotyphlops nigricans (MCZ 21473) and B. Leptotyphlops kafubi (FMNH 56374), both after List (1966). KEY to bone abbreviations from List, 1966: Ax = axis, At = atlas, Eo = exoccipital, F = frontal, M = maxilla, N = nasal, P = parietal, Pf = prefrontal, Po = prootic, So = supraoccipital. C. Leptotyphlops cairi, after Abdeen et al. (1991). KEY to bone abbreviations from Abdeen et al., 1991: B.OC. = basioccipital; B.SP. = basisphenoid; C.T.C. = cartilaginouis trebacula cranii; EX.OC. = exoccipital; FR. = frontal; L.P.P.MX. = lateral process of maxilla; MX. = maxilla; NA. = nasal; OC.CO. = occipital condyle; P.MX. = premaxilla; P.OT. = prootic; P.VO. = prevomer; PA. = palatine; PR. = parietal; PR.FR. = prefrontal; PR.L.DG. = lateral downgrowth of parietal; PT. = pterygoid; S.OC. = supraoccipital. The lines represent 1 mm to scale. The stipple indicates thin transparent membrane. Figure 2. Dorsal views of the skulls of Leptotyphlops. A. Leptotyphlops nigroterminus sp. nov. (ZMB 51610); B. Leptotyphlops macrurus (BMNH 1957.1.10.26); C. Leptotyphlops boulengeri (MCZ 40087); D. Leptotyphlops reticulatus (BMNH 1954.1.12.77). E. Leptotyphlops longicaudus (NMZB-UM 29371); F. Leptotyphlops blanfordii (BMNH 1977.833); G. Leptotyphlops nursii (FMNH 66158). H. Leptotyphlops scutifrons merkeri (NMZB 8089). The lines represent 1 mm to scale. KEY: f = frontal; n = nasal; p = parietal; pp = postparietal; so = supraoccipital.

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

PLATE 10. Figure 1. Leptotyphlops monticolus. Dorsal, lateral and ventral views of the head of NMZB 15309 — Katare, Kivu, D.R.C. The line represents 1 mm to scale. Figure 2. Leptotyphlops mbanjensis sp. nov. Dorsal, lateral and ventral views of the head of the holotype, MCZ 48040 — Mbanja, Lindi District, Tanzania. The line represents 1 mm to scale. Figure 3. Leptotyphlops keniensis sp. nov. Dorsal, lateral and ventral views of the head of the holotype, NMK/O. 2903 — Nyeri, Kenya. The line represents 1 mm to scale. Figure 4. Leptotyphlops aethiopicus sp. nov. Dorsal, lateral and ventral views of the head of the holotype, BMNH 1911.12.13.17 — near Harer, Ethiopia. The line represents 1 mm to scale.