Molecular phylogeny, classification, and biogeography of snakes of the Family Leptotyphlopidae (Reptilia, Squamata)
Author
Adalsteinsson, Solny A.
Department of Biology, 208 Mueller Lab, Pennsylvania State University, University Park, PA 16802 - 5301 USA.
Author
Branch, William R.
Bayworld, P. O. Box 13147, Humewood 6013, South Africa
Author
Trape, Sébastien
Laboratoire ECOLAG, UMR 5119, Université Montpellier II, cc 093, Place E. Bataillon, 34095 Montpellier Cedex 5, France
Author
Vitt, Laurie J.
Sam Noble Oklahoma Museum of Natural History and Zoology Department, 2401 Chautauqua Avenue, Norman, OK 73072, USA Corresponding author. E-mail: sbh 1 @ psu. edu
Author
Hedges, S. Blair
Department of Biology, 208 Mueller Lab, Pennsylvania State University, University Park, PA 16802 - 5301 USA.
sbh1@psu.edu
text
Zootaxa
2009
2009-10-01
2244
1
50
journal article
1175-5326
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
.