Thursday, December 31, 2020

[Herpetology • 2019] Kladirostratus gen. nov. & Psammophylax kellyi 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


 Kladirostratus acutus (Günther 1888) 

in Keates, Conradie, Greenbaum & Edwards, 2019. 

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 .

Keywords: geometric morphometrics, grass snake, molecular biology, phylogenetic analysis, Psammophiinae, taxonomy

Kladirostratus acutus comb. nov. 

 Kladirostratus acutus (Günther 1888) 

Kladirostratus gen. nov. Conradie, Keates & Edwards 
Proposed common group name: Branch's Beaked Snakes.

Type species: Psammophis acutus Günther 1888.

Etymology: The name Kladirostratus is derived from the combination of the Greek word κλάδος (klados) meaning “branch,” and the Latin word “rostratus” meaning beaked. The name honors Professor William R. Branch (1947–2018), Curator Emeritus of herpetology at Port Elizabeth Museum, in recognition of his many contributions to the herpetology of Africa, especially regarding snakes. We benefitted from his generosity as a mentor and he helped shape our careers, for which we are thankful. The name is masculine in gender.

Members of this genus: Kladirostratus acutus (Günther 1888) comb. nov. including the currently recognized subspecies Kladirostratus a. acutus and Kladirostratus a. jappi (Broadley, 1971); Kladirostratus togoensis (Matschie 1893) comb. nov. The latter is provisionally included in this genus based on morphological similarities, but this requires confirmation through molecular phylogenetic analysis.

Distribution: Kladirostratus a. acutus comb. nov. is known from most of Angola through northwestern Zambia, southern Democratic Republic of the Congo (DRC), into western Tanzania, northern Malawi, and north to Rwanda (fide Broadley, 1971). Kladirostratus a. jappi comb. nov. is known only from western Zambia and northeastern Angola (fide Broadley, 1971). Kladirostratus togoensis comb. nov. is known from Ghana, Togo, Central African Republic, northern DRC, and western Uganda (fide Broadley, 1971; Spawls et al., 2002). Occurs at elevations of 450–1,800 m.

Psammophylax kellyi sp. nov.

 Psammophylax kellyi sp. nov. Conradie, Keates & Edwards  
Proposed common name: Tanzanian Grass Snake or Tanzanian Skaapsteker.

Etymology. The specific epithet is a patronym in honor of Christopher M. R. Kelly for his considerable contribution to the systematics of the snake family Lamprophiidae.

Chad Keates, Werner Conradie, Eli Greenbaum and Shelley Edwards. 2019. 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. Journal of Zoological Systematics and Evolutionary Research.  57(4); 1039-1066.  DOI: 10.1111/jzs.12337 

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