Rhinoleptus Orejas-Miranda, Roux-Estève, and Guibé, 1970

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 : 25

Genus Rhinoleptus Orejas-Miranda, Roux-Estève, and Guibé, 1970

Type species. Typhlops koniagui Villers, 1956 , by monotypy.

Diagnosis. Species in this genus have 16 midbody scale rows, 14 midtail scale rows, 302–546 middorsal scale rows, 21–30 subcaudals, 2–4 supralabials, small anterior supralabials, 160–460 mm maximum adult total length, a body shape of 67–160 (total length/width), a relative tail length of 3.7–10.0 %, a tail shape of 3.5, no striped pattern, a brown dorsum, and brown venter (Table 2). They are distinguished from the other genus in this tribe, Guinea , by having 16 midbody scale rows (versus 14), 14 midtail rows (versus 12), 302–546 middorsal rows (versus 173–288), 21–30 subcaudals (versus 6–16), and a body shape of 67–160 (versus 24– 69.2). Only one species was included in the molecular phylogenetic analyses ( Figs. 3–4).

Content. Two species ( Table 1; Fig. 9), although see "Remarks" below.

Distribution. Rhinoleptus is distributed in West Africa ( Rhinoleptus koniagui ), including Senegal, and Guinea , and Mali ( Trape & Mané 2006); and in East Africa ( Rhinoleptus parkeri ), including Ethiopia ( Fig. 11).

Etymology. The generic name is masculine and derived from the Greek noun rhinos (nose) and Greek adjective leptos (thin), in allusion to the unusual rostral scale of Rhinoleptus koniagui , with its narrow and pointed anterior tip.

Remarks. We were unable to obtain a tissue sample of Rhinoleptus parkeri but assign it here to the genus Rhinoleptus because it shares with R. koniagui a series of unique or rare traits in the family: an unusually high number of midbody scale rows (16) and midtail scale rows (14), parietals small or undifferentiated, and occipitals undifferentiated. In his description of parkeri, Broadley (1999) considered these traits to be ancestral assuming that all other leptotyphlopids (apart from R. koniagui ) formed a monophyletic group. Wallach (1998) also found that parkeri branched early in the tree based largely on visceral characters, and the position of this species was discussed further by Broadley and Wallach (2007). However, considering the phylogenetic relationships obtained in our study ( Figs. 3–4) showing that Rhinoleptus is not the closest relative of all other leptotyphlopids, those characteristics of R. parkeri are now re-evaluated as being derived within Rhinoleptini rather than ancestral among leptotyphlopids.

The specimen of Rhinoleptus from West Africa sampled here ( Fig. 9B) agrees in many respects with Rhinoleptus koniagui (e.g., greatly enlarged rostral, 16 scale rows, oblique orientation of head scales, Villiers 1956). However, it and some other specimens from Senegal lack the distinctive horn on the rostral of R. koniagui (Hedges and Trape, unpub. obs.). We conservatively refer it to Rhinoleptus koniagui but note that additional material may signal the presence of an additional species of Rhinoleptus .