Phylogenetic relationships among the Stiletto Snakes (genus Atractaspis) based on external morphology

Abstract

Stiletto Snakes (genus Atractaspis) are the most poorly studied of the three clades of snakes with front-fanged venom-delivery systems. Fossorial and endemic to Africa and the Middle East, Atractaspis possess uniquely derived mobile fangs that allow them to perform a ‘side-stabbing’ method of envenomation, rather than the frontal strike of most other venomous snakes. While many studies have examined the functional anatomy of these unique fangs, the evolutionary history of Atractaspis has been comparatively neglected by researchers. While several evolutionary hypotheses exist for relationships within the Atractaspididae, no study has focused on the phylogenetic relationships within the genus Atractaspis itself. This study presents the first attempt to reconstruct the phylogenetic history of 14 species within this genus, using external morphological data. Using Macrelaps and Homoroselaps as alternate outgroups, We compare the results of two phylogenies and provide a starting point for an investigation of the evolutionary history of this remarkable yet relatively little-known genus.