Tetracheilostomina Hedges, Adalsteinsson, & Branch

Adalsteinsson, Solny A., Branch, William R., Trape, Sébastien, Vitt, Laurie J. & Hedges, S. Blair, 2009, Molecular phylogeny, classification, and biogeography of snakes of the Family Leptotyphlopidae (Reptilia, Squamata), Zootaxa 2244, pp. 1-50 : 22

Subtribe Tetracheilostomina Hedges, Adalsteinsson, & Branch , New Subtribe

Type genus. Tetracheilostoma Jan, 1861: 191 .

Diagnosis. Tetracheilostomina is distinguished from the other two subtribes of Epictini by usually having four supralabials (two in Epictina and 2–3 in Renina ) (Table 2). The support for this group was 100% BP and 100% PP for the four-gene tree ( Fig. 3); only one of the two genera was included in the nine-gene tree ( Fig. 4).

Content. Two genera and seven species ( Table 1; Fig. 7).

Distribution. Tetracheilostomina is distributed in the West Indies: on the island of Hispaniola in the Greater Antilles, and on Martinique, Saint Lucia, and Barbados in the Lesser Antilles.

Remarks. Tetracheilostomina includes species in the former " bilineatus Group" of " Leptotyphlops " ( Hedges 2008; Thomas 1965; Thomas et al. 1985). The high number (four) of supralabials is rare among leptotyphlopids, otherwise occurring only in Rhinoleptus . As a unifying character for this West Indian radiation it is further supported by the molecular phylogeny ( Fig. 3). However, the included species are considerably divergent in other scale characters, body size, and coloration. The species from Hispaniola have a high number of middorsal scales, are thin, and pale brown or pink in color. In contrast, the Lesser Antillean species have a low number of middorsals, are stout, and dark brown in color with dull yellowish stripes. The molecular phylogeny supports the distinction of these two groups of species and we recognize them here at the generic level.