Genetic structuring of the widespread genus Psammophylax (Fitzinger 1843), with the description of a new genus and species. Genetic structuring in Psammophylax (Fitzinger 1843)

Psammophylax (Fitzinger 1843) is a widespread genus of grass snakes that is under-studied in Africa. A genetic phylogeny of six of the seven currently described species of Psammophylax was estimated utilizing multiple phylogenetic and distance-based methods. To support the genetic analyses, we conducted morphometric analyses on the full body (traditional morphometrics) and on the head separately (geometric morphometrics). Phylogenetic analyses recovered a similar topology to past studies, but with better resolution and support for the nodes. Psammophylax acutus was recovered as sister to its congeners, and sequence divergence values and morphometrics supported the recognition of a new genus for the taxon. Increased sampling along the east coast (Tanzania, Kenya and Ethiopia) recovered Psammophylax multisquamis as paraphyletic, indicating that there is a previously unrecognised species of Psammophylax in Tanzania and that the distribution of P. multisquamis is likely restricted to Kenya and Ethiopia. We found substantial genetic structuring within the genus, supported by significantly different head shapes between P. acutus and other members of Psammophylax. Inclusion of specimens from the more remote parts of Africa in future analyses may result in the recovery of additional diversity within Psammophylax.