Paradentalium Cotton & Godfrey, 1933

Caetano, Carlos Henrique Soares, Scarabino, Victor & Absalão, Ricardo Silva, 2006, Scaphopoda (Mollusca) from the Brazilian continental shelf and upper slope (13 º to 21 ºS) with descriptions of two new species of the genus Cadulus Philippi, 1844, Zootaxa 1267, pp. 1-47 : 9

Paradentalium Cotton & Godfrey, 1933

Type species

Dentalium intercalatum Gould, 1859 (by original designation).

Diagnosis

Shell medium to large, slender, moderately curved, solid, shiny, polished; translucent, white or yellow. Six primary ribs, dorsal most prominent, one ventral, four latero­ventral. Secondary ribs present, number variable. Ribs round, flat or angled; intercostal spaces smooth or finely striated longitudinally, straigth on dorsal side, convex on ventral side. Apex simple, truncate, lumen circular, frequently with short terminal pipe. Section hexagonal at apex, subcircular or hexagonal at mouth. Oral aperture generally thin, fresh specimens translucent.

Remarks

This genus included two sets of species: one presents a hexagonal apex with similar intercostal spaces and equidistant primary ribs usually reaching the oral aperture, resulting in a hexagonal section also at the aperture. In the other group, the dorsal and two laterodorsal ribs are more prominent while ventral ones are less noticeable. This configuration results in intercostals spaces with different size and a circular or subcircular oral section in adults specimens. Further studies are needed to test the characters consistency for each of the above mentioned set of species and the need to split them in two different genera.