Leptotyphlops scutifrons merkeri (Werner)

Published, First, 2007, A revision of the genus Leptotyphlops in northeastern Africa and southwestern Arabia (Serpentes: Leptotyphlopidae), Zootaxa 1408, pp. 1-78 : 43-44

Leptotyphlops scutifrons merkeri (Werner) ( Plate 12 , Fig. 3)

Merker's worm snake

Glauconia conjuncta — Boulenger, 1893: 67 (part, Kilimanjaro), 1915: 617; Sternfeld, 1910: 13; Angel, 1925: 31.

Stenostoma conjuncta — Tornier, 1896: 67 (Korogwe).

Glauconia scutifrons — Lönnberg, 1907: 14.

Glauconia signata — Sternfeld, 1908: 243, 1910: 13; Werner, 1917: 203 (part, Kibwezi).

Glauconia merkeri Werner, 1909 , Jh. Ver. Vaterl. Naturk. Württemberg, 65: 61. Type locality: Moshi, base of Mt. Kilimanjaro, Tanzania (03°12’S, 37°22’E, 810 m), lectotype SMNS 4170, collected by H. Merker, 1904–1905; Sternfeld, 1910: 13; Boulenger, 1915b: 617; Loveridge, 1923: 874, 1924: 4.

Glauconia emini — Loveridge, 1916: 82 (part, Kyambu).

Glauconia distanti — Loveridge, 1923: 874, 1929: 18 (Morogoro).

Leptotyphlops distanti — Barbour & Loveridge, 1928: 109; Loveridge, 1929: 18.

Leptotyphlops conjuncta — Loveridge, 1933: 224 (part), 1936: 232.

Leptotyphlops conjuncta conjuncta — Barbour & Loveridge, 1946: 116; Loveridge, 1951: 187, 1957: 246 (part).

Leptotyphlops scutifrons merkeri — Broadley & Watson, 1976: 484; Hahn, 1980: 26; Broadley & Howell, 1991: 22; Hallermann & Rödel, 1995: 7; Wallach, 1996: 426.

Leptotyphlops conjunctus conjunctus — Spawls, 1978: 2 (part).

Leptotyphlops emini emini — Spawls, 1978: 3 (part, Baringo).

Leptotyphlops signatus — Hahn, 1980: 26 (part, Tabora & Kibwezi).

Leptotyphlops scutifrons — McDiarmid et al., 1999: 41 (part); Spawls et al., 2002: 299 (part).

Diagnosis. A subspecies of Leptotyphlops scutifrons , distinguished from the typical form by having 12 scale rows on the tail and a narrower wedge-shaped rostral (unguiform in the typical form), it is also smaller in average size.

Description. Body cylindrical, with head and neck broadened and flattened, the short tail tapers abruptly to a small terminal spine.

Snout rounded, frontal fused with rostral, rostral broad (0.49–0.64 head width, mean = 0.54), wedgeshaped, broader than a nasal anteriorly and extending beyond the level of the eyes, a distinct preoral groove present ventrally. Behind rostral, upper lip bordered by infranasal (nostril nearer to rostral than supralabial along nasal suture), a small anterior supralabial with width along lip 1.0–1.5 times that of infranasal, large ocular with the small eye at the upper anterior edge, and tall posterior supralabial. Supraoculars pentagonal, anteriorly wedged between upper nasal and ocular, posteriorly wedged between rostral and hexagonal postfrontal, which is smaller than a supraocular and the hexagonal interparietal and interoccipital. Parietals oblique, slightly larger than the fused occipitals, in contact with the posterior supralabials. Temporal single. No mental, four infralabials.

Body covered with 14 rows of smooth, imbricate, subequal scales. Reduction to 12 scale rows on the tail takes place just posterior to the subtriangular cloacal shield. Middorsals 201–304; subcaudals 18–30.

Total length/diameter ratio 40–86; total length/tail ratio 7.9–21.0.

Uniform dark brown to black dorsum and venter, often with some irregular white patches on lower lip, chin and (rarely) throat.

Size. Largest specimen (NMK/O. 2854 — Naivasha, Kenya) 220 + 11 = 231 mm.

Remarks. This race apparently intergrades with typical Leptotyphlops scutifrons in southeastern Tanzania: specimens with both 10 and 12 scale rows on the tail occur at Liwale and Morogoro. Hahn (1979) demonstrated that Stenostoma signatum Jan, 1861 (type locality unknown) is a senior synonym of Leptotyphlops amazonicus Orejas-Miranda, 1969 of Venezuela.

The situation with regard to the type specimens of Leptotyphlops scutifrons merkeri ( Werner, 1909) is complex. Broadley & Watson (1976), believing that the two Merker syntypes in MSNS were destroyed during World War II, selected a Wiedenmann topotypical specimen (SMNS 2517A) as lectotype, not realizing that a Merker syntype (MCZ 31627) had been exchanged with the MCZ in 1931 ( Barbour & Loveridge, 1946). MCZ 31627 fits the smaller of the two specimens described (and the logical one for SMNS to exchange with MCZ): total length 160 mm (now 150 mm from shrinkage) and tail length/total length 11.5 times (now 11.1 times). Schlüter & Hallermann (1997) then discovered the other SMNS Merker syntype (recatalogued as SMNS 4170) and designated it the lectotype and SMNS 2517A–B as paralectotypes. However, since SMNS 2517A–B are not part of the type series they are only topotypes but MCZ 31627 is a paralectotype.

Habitat. Savanna. Freshly cleared ground beneath a fig tree ( Loveridge, 1936).

Distribution. Highland plateau areas in south-central Kenya, extending into eastern Tanzania, 0–1500 m ( Plate 11 ).

Localities. KENYA. Amboseli Nat. Park BMNH 1966.907 ; ZFMK 27482 ; Hunters' Lodge MHNG 1566.50 ; Kiambu NMK / O 574 , 1909 ; Kibwezi MCZ 40082 ; ZMB 11925, 21167–72 , 25070 (3) , 29081 (5); Kilimanjaro BMNH 87.11 . 3.20, 87.11.3.77; Kitui BMNH 1902.5.26.12–13; Mt. Longonot NMK / O 3028 ; Muranga ( Fort Hall ) BMNH 1904.12.23.7; MCZ 18178 ; MNHN 1923.121 ; Nairobi CAS 122378 , 153251– 52 , 186083 ; MHNG 2236.27 ; MNHN 1904.307 , 1940.158 ; NMK /O. 573, 575–76, 580, 935, 3049; NMZB 6402 ; Naivasha NMK /O. 2854; Namanga NMK /O. 2685; Taita ZMB 9245 , 53612–13 ; Tsavo Nat. Park BMNH 1974.3970 . TANZANIA. Bamba Ridge Forest Reserve NMZB 17173 ; Dar es Salaam BMNH 1973.118 , 1975.868 – 70 , 1976.2297 ; CAS 162585–87 ; NMZB 6682 , 8082,12323 ; Gendagenda South Forest Res. NMZB 11363 ; Ilonga BMNH 1984.722 ; Kazimzumbwe Forest Res. KMH 11292; Kilosa UMMZ 61193 ; Kilwa MCZ 52627, 54511–14 ; Kiono Depression KMH 6621; NMZB 17166 ; Kiwengoma Forest Res. KMH 6672; Kitaya MCZ 48035 ; Lake Manyara Nat. Park NMZB 9938 ; Liwale MCZ 51305, 52628–31 , 54515–17 , 55831–32 ; Longido West MCZ 18183 ; USNM 62896–97 ; Longuza North Forest Res. NMZB 14287 ; Manga Forest Res. NMZB 14101 , 14107 , 14109 ; Mazimbu, Ngorongoro NMZB 11371–73 ; Mikumi Nat. Park NMZB 8089 *, 9621–22; Morogoro AMNH 16875–78 ; BMNH 1970.2419 ; MCZ 18176 ; NMZB 6681 , 7446 ; UMMZ 61192 , 61195 ; ZMB 26847 ; Moshi MNHN 1923.122 ; SMNS 2517 (3, including paralectotypes of G. merkeri Werner ) ; Mtai Forest Res. NMZB 14789 ; Mto wa Mbu BMNH 1936.9.6.1; 15 km SE of Olduvai CAS 111959 ; Ruponda MCZ 50068 ; Ruaha Nat. Park NMZB 13161 ; Zaraninge Forest Res. CAS 202688 ; KMH 11337 .

Figures

PLATE 11. Leptotyphlops. Distribution of the Leptotyphlops scutifrons species group in East Africa. Type localities are labelled.

PLATE 12. Figure 1. Leptotyphlops nigroterminus sp. nov. Dorsal and lateral views of the head of the holotype, MCZ 54813 — Karema, Tanzania. The line represents 1 mm to scale. Figure 2. Leptotyphlops latirostris. Dorsal, lateral and ventral views of the head of MCZ 53261/57459 from Uvira, DDC. Drawings by J. Boundy. The line represents 1 mm to scale. Figure 3. Leptotyphlops scutifrons merkeri. Dorsal, lateral and ventral views of the head of the syntype, MCZ 31627 — Moshi, Tanzania. Drawings by J. Boundy. The line represents 1 mm to scale. Figure 4. Dorsal views of the heads of: A. Leptotyphlops latirostris. MRAC 18014 (Uvira, Kivu), compared with B. Leptotyphlops scutifrons pitmani. MRAC 18006 (Rwankuba, Rwanda), after Laurent (1956). The lines represent 1 mm to scale.