Cathetorhinus Duméril & Bibron, 1844

Pyron, Robert Alexander & Wallach, Van, 2014, Systematics of the blindsnakes (Serpentes: Scolecophidia: Typhlopoidea) based on molecular and morphological evidence, Zootaxa 3829 (1), pp. 1-81 : 44

Cathetorhinus Duméril & Bibron, 1844

Type species. Cathetorhinus melanocephalus Duméril & Bibron, 1844

Species content. Cathetorhinus melanocephalus .

Diagnosis. Cathetorhinus can be distinguished from all other typhlopoids by the combination of a T-II SIP and absence of preocular (fused with nasal). Small-sized (total length 183 mm), slender-bodied (length/width ratio 92) snakes with 18 scale rows throughout, 525 total middorsals, moderate tail ( 2.7 % of total length) with 20 subcaudals (length/width ratio 2.5), and minute apical spine. Dorsal head profile bluntly rounded, lateral profile pointed with a ventral rostral keel that terminates in a blunt point, large oval rostral ( 0.71 head width), eye discernible as a faint eyespot, and postocular single. Coloration of head in preservative is blackish-brown, dorsum tan with lighter venter.

Phylogenetic definition. This genus is currently monotypic, but would include any newly discovered species more closely related to Cathetorhinus melanocephalus than to Gerrhopilus ater .

Etymology. Unclear; likely refers to keeled, pointed condition of snout, from the Greek for perpendicular (cathetos) and having such a nose (rhinus).

Distribution. Unknown. Collected during the Baudin voyage ( 1800–1804), which made landfall at the Azores, Cape of Good Hope ( South Africa), Mauritius, W Australia, and Timor. Timor seems the most likely origin based upon these possible localities and their ophiofaunas, though one author suggested a potential origin from Mauritius ( Cheke 2010).

Remarks. The genus Cathetorhinus is resurrected here from the synonymy of Ramphotyphlops ( Hedges et al. 2014) . Previous authors considered Typhlops melanocephalus Typhlopidae incertae sedis, including Dixon & Hendricks ( 1979), Hahn ( 1980), and McDiarmid et al. ( 1999). The type and only known specimen ( MNHN 138), which is in poor condition, has been re-examined by Wallach & Pauwels ( 2008), and does not fit the definitions of any other typhlopoid genera. Those authors resurrected Cathetorhinus . The combination of a T-II SIP and 18 dorsal scale rows clearly allies it with Gerrhopilidae , as this is a common combination of characters in Gerrhopilus , and only found in some individuals of one other African typhlopid species ( Letheobia debilis ; Table 2). Thus, we transfer Cathetorhinus to Gerrhopilidae (Table 1).