Leptotyphlops parkeri Broadley, 1999

Published, First, 2007, A revision of the genus Leptotyphlops in northeastern Africa and southwestern Arabia (Serpentes: Leptotyphlopidae), Zootaxa 1408, pp. 1-78 : 15-17

Leptotyphlops parkeri Broadley ( Plate 6 , Fig. 1)

Parker's worm-snake

Leptotyphlops cairi — Parker, 1949: 19; Largen & Rasmussen, 1993: 324 (part, Daggah Bur).

Leptotyphlops parkeri Broadley,1999 , Arnoldia Zimbabwe 10: 141. Type locality: Degeh Bur, Harege Region, Ethiopia (8°13'N, 43°30'E, elevation 1067 m), holotype BMNH 1949.2 .3.47, collected by R.H.R. Taylor, 1932–33.

Diagnosis. Distinguished from all other species of the genus in having 16 scale rows on the body, 14 on the tail, and an undifferentiated cloacal shield. In addition the paravertebral scale rows extend forward to separate the parietals from the postfrontal.

Description. Body cylindrical, with head and neck broadened and flattened, the moderate tail tapers slightly to a small terminal cone.

Snout slightly hooked in lateral profile, rostral moderate (0.43 head width) and subtriangular, extending nearly to the level of the eyes, with a distinct preoral groove ventrally. Behind rostral, upper lip bordered by infranasal (nostril midway between rostral and supralabial along nasal suture), short anterior supralabial with width along lip equal to that of infranasal, large ocular (eyes not visible due to removal of skull), and moderate posterior supralabial. Supraoculars strongly oblique, three times as long as wide, anteriorly wedged between supranasal and ocular, posteriorly wedged between the large subtriangular postfrontal and a much smaller subhexagonal postparietal. Bordering the postparietals and the postfrontal is a pair of small interparietals followed by an interoccipital similar in size to the middorsals following it. Parietals transverse, separated from the postfrontal by a postparietal [= forward extension of the paravertebral scale row], in contact with the posterior supralabial. Occipitals not fused, a pair of scales occupying the space of the typically fused leptotyphlopid occipital. Two temporals between lateral occipital and posterior supralabial. No mental, the lower jaw has been damaged by removal of the skull prior to its registration at the Natural History Museum.

Body covered with 16 rows of smooth, imbricate, subequal scales, reducing to 14 rows on the tail just caudad of the undifferentiated cloacal shield. Total middorsals 302; subcaudals 28.

Total length/tail ratio 16.0; total length/diameter ratio 67.

Three middorsal scale rows pigmented golden brown, next lateral row irregularly pigmented, venter unpigmented, white.

Size. Length of holotype 150 + 10 = 160 mm, diameter 2.4 mm.

Distribution. Only known from the type locality in Chrysopogon /Dactyloctenium grassland on the edge of the Ogaden ( Plate 5 ).

Discussion. The only other species in the family with 16 scale rows on the body is Rhinoleptus koniagui (Villiers) . Leptotyphlops parkeri shares several characters with it that may be plesiomorphic:

1. In Rhinoleptus there are no differentiated parietal or occipital shields. In L. parkeri the parietals are small and separated from the frontal by the paravertebral scale rows, while there are no differentated occipitals. In all other Leptotyphlops the parietals are large and in good contact with the frontal, while the occipitals on each side are often fused to form equally large shields.

2. Leptotyphlops parkeri agrees with Rhinoleptus in having 16 scale rows on the body, reducing to 14 rows on the first third of the tail. All other members of the family have 14 scale rows on the body, usually reducing to 12 or 10 rows on the tail.

3. Leptotyphlops parkeri agrees with Rhinoleptus in having an undifferentiated cloacal shield.

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.