Typhlops

Abstract: The evolutionary history and taxonomy of worm-like snakes (scolecophidians) continues to be refined as new molecular data are gathered and analyzed. Here we present additional evidence on the phylogeny of these snakes, from morphological data and 489 new DNA sequences, and propose a new taxonomic framework for the family Typhlopidae. Of 257 named species of typhlopid snakes, 92 are now placed in molecular phylogenies along with 60 additional species yet to be described. Afrotyphlopinae subfam. nov. is distributed almost exclusively in sub-Saharan Africa and contains three genera: Afrotyphlops, Letheobia, and Rhinotyphlops. Asiatyphlopinae subfam. nov. is distributed in Asia, Australasia, and islands of the western and southern Pacific, and includes ten genera: Acutotyphlops, Anilios, Asiatyphlops gen. nov., Cyclotyphlops, Grypotyphlops, Indotyphlops gen. nov., Malayotyphlops gen. nov., Ramphotyphlops, Sundatyphlops gen. nov., and Xerotyphlops gen. nov. Madatyphlopinae subfam. nov. occurs only in Madagascar and includes one genus: Madatyphlops gen. nov. Typhlopinae occurs in the New World and includes four genera: Amerotyphlops gen. nov., Antillotyphlops gen. nov., Cubatyphlops gen. nov., and Typhlops. Scolecophidians are the most ancient (deeply-branching) group of living snakes and their relationships track plate tectonics better than any other vertebrate group. Molecular data reveal large numbers of undescribed species, inferring that the true species diversity of these snakes is greatly underestimated.

Abstract: The blindsnake superfamily Typhlopoidea (Gerrhopilidae, Typhlopidae, and Xenotyphlopidae) is a diverse, widespread part of the global snake fauna. A recent systematic revision based on molecular phylogenetic analyses and some morphological evidence presented a preliminary solution to the non-monophyly of many previously recognized genera, but additional clarification is needed regarding the recognition of some species and genera. We rectify these problems here with a new molecular phylogenetic analysis including 95 of the 275 currently recognized, extant typhlopoids, incorporating both nuclear and mitochondrial loci. We supplement this with data on the external, visceral, and hemipenial morphology of nearly all species to generate a revised classification for Typhlopoidea. Based on morphological data, we re-assign Cathetorhinus from Typhlopidae to Gerrhopilidae. Xenotyphlopidae maintains its current contents (Xenotyphlops). In Typhlopidae, one monotypic genus is synonymized with its larger sister-group as it cannot be unambiguously diagnosed morphologically (Sundatyphlops with Anilios), and two genera are synonymizedwith Typhlops (Antillotyphlops and Cubatyphlops), as they are not reciprocally monophyletic. The genus Asiatyphylops is renamed Argyrophis, the senior synonym for the group. We erect one new genus (Lemuriatyphlops) for a phylogenetically distinct species-group in Asiatyphlopinae. Fourteen of eighteen recognized typhlopid genera are maintained in four subfamilies: Afrotyphlopinae (Afrotyphlops, Grypotyphlops [re-assigned from Asiatyphlopinae], Letheobia, and Rhinotyphlops), Asiatyphlopinae (Acutotyphlops, Anilios, Cyclotyphlops, Indotyphlops, Malayotyphlops, Ramphotyphlops, and Xerotyphlops), Madatyphlopinae (Madatyphlops), and Typhlopinae (Amerotyphlops and Typhlops), some with altered contents. Diagnoses based on morphology are provided for all 19 typhlopoid genera, accounting for all 275 species. This taxonomy provides a robust platform for future revisions and description of new species.

Abstract: For nearly a century the species concept used for the Crustacea Leptostraca has been very wide, particularly in the case of the cosmopolitan genus Nebalia. It is shown that the characters upon which this concept rests are unsatisfactory. On the whole chaetotaxonomic characters in the Leptostraca are, with exceptions, variable and growth-related and thus not well suited for identification of species. On the other hand the shape and proportions of parts provide constant and reliable characters. Against this background the principles for working on leptostracan taxonomy are laid down and a model for description of species is presented. It is shown that species decriptions should always be based on females. The model is applied in a revision of the leptostracan species of the European shelf. Five species of Nebalia are recognized, two of them new to science, and a new genus, Sarsinebalia, is introduced with {Nebalia typhlops G.O. Sars as genotype. It is demonstrated that in their geographical distrib...

Abstract: The systematic arrangement of the worm snakes (Typhlops) from the continental western hemisphere is presented. Allocations of many names historically assigned to Central and South American Typhlops are clarified. The continental Typhlops include nine species, two of which are described as new. The intraspecific variation of all species is explored within the limitations of known specimens. Three major radiations of New World Typhlops are postulated to account for the radiations of the present species groups.