A snake in the grass: Genetic structuring of the widespread African grass snake (Psammophylax Fitzinger 1843), with the description of a new genus and a new species
Chad Keates, Werner Conradie, Eli Greenbaum, Shelley Edwards
Psammophylax (Fitzinger 1843) is a widespread yet poorly studied genus of African grass snakes. A genetic phylogeny of six of the seven species was estimated using multiple phylogenetic and distance‐based methods. To support the genetic analyses, we conducted morphological analyses on the body (traditional morphology) and head (geometric morphometrics) separately. Phylogenetic analyses recovered a similar topology to past studies, but with better resolution and node support. We found substantial genetic structuring within the genus, supported by significantly different head shapes between P. a. acutus and other Psammophylax. Psammophylax a. acutus was recovered as sister to its congeners, and sequence divergence values and morphometrics supported its recognition as a new genus. Increased sampling in East Africa (Tanzania, Kenya, and Ethiopia) revealed that Psammophylax multisquamis is polyphyletic, necessitating the description of a new, morphologically cryptic species from northern Tanzania. The distribution of P. multisquamis sensu stricto is likely restricted to Kenya and Ethiopia. The study has further resolved multiple aspects of Psammophylax systematics, including the taxonomic validity of two central African subspecies, P. variabilis vanoyei (Laurent 1956) and P. tritaeniatus subniger (Laurent 1956). Inclusion of specimens from the more remote parts of Africa, in future analyses, may result in the recovery of additional diversity within Psammophylax.
geometric morphometrics, grass snake, molecular biology, phylogenetic analysis,