Causus nasalis Stejneger, 1893

Marques, Mariana P., Parrinha, Diogo, Lopes-Lima, Manuel, Tiutenko, Arthur, Bauer, Aaron M. & Ceríaco, Luis M. P., 2024, An island in a sea of sand: a first checklist of the herpetofauna of the Serra da Neve inselberg, southwestern Angola, ZooKeys 1201, pp. 167-217 : 167-217

Causus nasalis Stejneger, 1893

Fig. 10 c

Records.

Mamué riparian area [- 13.8006, 13.1230, 706 m] ( CAS 263034; INBAC / AMB 10324).

Comments.

Bocage (1895) suggested that Angolan populations of Causus resimus (Peters, 1862) belonged to a new variety, which he named angolensis . This decision was supported, according to the author, by morphological differences between the Angolan populations and the nominotypical form. A few years earlier, Stejneger (1893) had already described what he called Causus nasalis from “ West Africa ” based on a specimen collected during the United States Eclipse Expedition to West Africa in 1890. Since Stejneger did not know the exact collection locality of the type, he assumed that it was “ Cunga ” [most likely Fazenda Cunga, on the banks of the Kwanza River, Luanda Province]. A label bearing this information accompanied another specimen ( USNM 16074), which we examined, and which is currently labelled as paratype in the collections of the National Museum of Natural History, Smithsonian Institution, USA ( USNM). Neither nasalis nor angolensis has been commented upon by subsequent authors. The recently collected specimens from Serra da Neve could represent this distinct Angolan population, considering not only its morphological differences but also its geographic isolation from the rest of the known distribution of the topotypical form. Our specimens agree entirely with the morphological description provided by both Stejneger (1893) and Bocage (1895). Given this, we here recognize C. nasalis as a valid species for Angola, endemic to the coastal areas of the country, from Luanda to Namibe provinces.

Figures

Figure 10. a Python natalensis (skin) b Bitis (Macrocerastes) gabonica c Causus nasalis d Boaedon variegatus e Hemirhagerrhis viperina f Lycophidion hellmichi g Psammophis subtaeniatus. Photographs by LMPC (a, c, f); AT (d, e, g) and DP (b).