Typhlops biminiensis

Thomas, Richard & Hedges, Blair, 2007, Eleven new species of snakes of the genus Typhlops (Serpentes: Typhlopidae) from Hispaniola and Cuba, Zootaxa 1400, pp. 1-26 : 15

Typhlops biminiensis ( Fig. 8 A)

Diagnosis: Typhlops biminiensis sensu stricto is one of the largest West Indian species of Typhlops , TL (total length) to 370 mm. The preocular contacts supralabials 2 and 3, which is a characteristic of the T. biminiensis Group ( Richmond, 1955; Thomas, 1968) of West Indian species. This feature also occurs in all mainland Central and South American species ( Dixon & Hendricks, 1979) but not most West Indian species, which belong to another West Indian radiation of Typhlops , the major Antillean radiation (MAR) ( Thomas, 1976). Aside from the preocular­contact character, T. biminiensis is distinguished from members of the MAR by its broadly angled preocular (93–125°) and its broad rostral scale (RW1/RL1 0.81–1.08). The only currently recognized member of the Major Antillean Radiation occurring within the range of T. biminiensis is T. lumbricalis of Cuba and the Great and Little Bahama Bank islands. From described members of the Typhlops biminiensis group ( T. caymanensis , T. epactius , and T. paradoxus ), T. biminiensis sensu stricto differs in its larger size and broad, nearly round, rostral scale ( Fig. 8 A) with RW1/RL1 values of over 0.81. It further differs from T. caymanensis by its greater number of scale rows (24 or 22 initially versus 20 rows for T. caymanensis ) and greater number of middorsal scales (454–537 versus 351–408). From the Cuban species ( Fig. 8 ) it differs in having a larger rostral size (RW1+RL3; Fig. 10 A), longer snout (NE; Fig. 10 B), and smaller preocular apical diameter (PD; Fig. 10 C). Because the new Cuban species can thus be distinguished from T. biminiensis , T. caymanensis , T. epactius , and T. paradoxus , our discussion below will focus mostly on diagnostic traits among the Cuban species previously confused with T. biminiensis .

Description: Snout rounded, slightly lobed. Rostral broad and rounded in dorsal aspect, nearly as broad as long in most specimens (RW1/RL1 0.81–1.08), broadly oval, almost circular; not flared on apex; minimal umbo; no labial flare. PA 93–125°, apex rounded; lower portion of preocular contacting upper labials two and three. Anterior nasal width as a proportion of RW1 0.30–0.37. OL 1/2 height, OS 0.09–0.28. Rostronasal pattern strongly divergent. Postocular 3–4 times higher than long, rarely two postoculars as a result of a second scale encroaching minimally on the postocular space. First parietal standard, spanning two scale rows or slightly less. Second parietal present and similar in size to the first, or absent. TL to 380 mm. TL/TA 42–60. TL/MBD 39–51. Middorsal scales 454–537. Scale rows 22 with no posterior reduction or 24 reducing to 22 at about midbody or not reducing at all. Coloration bicolor with dorsal pigmentation (pale brown) ending abruptly along a midlateral or dorsolateral line by dropping out of pigmentation on individual scales, resulting in a jagged line of separation between pigmented and non­pigmented scales; or color fading gradually over 2– 3 scale rows, without dropping out of pigment; a combination of these effects may occur with a gradual transition anteriorly and dropping out of pigmented scales posteriorly. Hemipenes attenuate.

Distribution: Bahamas: Bimini Islands, Andros Island, New Providence, Elbow Cay (Cay Sal Bank), and Ragged Islands.

The first of the new species having affinities with T. biminiensis occurs on the southern coast of eastern Cuba, in the region of Guantánamo Bay. It may be known as

Figures

FIGURE 8. Head scalation in the Typhlops biminiensis Group, including seven new species from Cuba. (A) T. biminiensis (ASFS V 11655), from Elbow Cay, Cay Sal Bank, Bahamas. (B) T. paradoxus (ASFS V 12067), from Great Inagua, Bahamas. (C) T. epactius (ASFS V 11673), from Cayman Brac, Cayman Islands. (D) T. caymanensis (ASFS V 17112), from Grand Cayman, Cayman Islands. (E) T. perimychus (USNM 564800), holotype, from Guantanamo Bay Naval Station, Cuba. (F) T. arator (MNHNCu 191), holotype, from El Narigon, La Habana, Province, Cuba). (G) T. anousius (MNHNCu 4550), holotype, from 3.5 km E Tortuguilla, Guantánamo Province, Cuba. (H) T. notorachius (MNHNCu 4551), holotype, from 9.4 km W Imias, Guantánamo Province, Cuba. (I) T. contorhinus (MNHNCu 4552), holotype, from 4.9 km S La Tinta, Guantánamo Province, Cuba. (J) T. anchaurus (MNHNCu 4553), holotype, from within 1 km of Cueva de Agua (2.5 km airline NW Maisí), Guantánamo Province, Cuba. (K) T. satelles (SMF 61303), holotype, from Rancho Luna, about 12 km airline S Cienfuegos, Cienfuegos Province, Cuba.

FIGURE 10. Variation in measurements of Typhlops biminiensis and Cuban species of the Typhlops biminiensis Group. For all graphs (A – F), the following species are indicated by symbols: T. anchaurus (open diamond), T. anousius (closed square), T. arator (closed diamond), T. biminiensis (open circle), T. contorhinus (open triangle), T. notorachius (closed triangle), T. paradoxus (open square), T. perimychus (closed circle), T. satelles (“ X ”). Trendlines are indicated on some graphs for T. biminiensis and T. perimychus. See text for definition of abbreviations.