Phreatomascogos Czaja & Estrada-Rodriguez

Czaja, Alexander, Cardoza-Martinez, Gabriel Fernando, Meza-Sanchez, Iris Gabriela, Estrada-Rodriguez, Jose Luis, Saenz-Mata, Jorge, Becerra-Lopez, Jorge Luis, Romero-Mendez, Ulises, Estrada-Arellano, Josue Raymundo, Garza-Martinez, Miguel Angel & Paulin, Jose Antonio Davila, 2019, New genus, two new species and new records of subterranean freshwater snails (Caenogastropoda; Cochliopidae and Lithoglyphidae) from Coahuila and Durango, Northern Mexico, Subterranean Biology 29, pp. 89-102 : 91

Genus Phreatomascogos Czaja & Estrada-Rodriguez gen. n.

Type species:

Phreatomascogos gregoi sp. n. by present designation.

Diagnosis.

Shell small, valvatiform to low trochoid; transparent to whitish; teleoconch with one or two prominent, sometimes almost winged keels; umbilicus almost completely covered (bordered) by a basal keel-like structure; operculum near circular, paucispiral, strongly campanulate.

Differential diagnosis.

The characteristic combination of mentioned three shell features (bordered umbilicus, prominent keels and strong campanulate operculum) separate the new genus clearly from shells of all other subterranean genera. Similar in size and general form are only shells of some members of Phreatodrobia Hershler and Longley from Texas, a genus which includes exclusively subterranean species. Nevertheless, none species of this genus possess keeled shells with a bordered umbilicus, smooth protoconch and such trochoid elevated opercula. The monotypic, recently erected (based on shell morphology) genus Novalis Quiñonero-Salgado & Rolán, 2017 ( Hydrobiidae ) from Spain resembles in some details the material from Coahuila ( Quiñonero-Salgado and Rolán 2017). However, beside of the great geographic disjunction, shells of this European species are not keeled and have a different basal structure which do not cover the umbilicus.

Etymology.

The genus name derives from the word phreatos (referring to the subterranean habitat) and from Mascogos , an afrodescendant ethnic group of Coahuila which escaped the threat of slavery in the United States and lives since 1852 in the Sabinas/ Álamos River area.