|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||Age range and collections|
Gastropoda - Rissoidae
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|W. F. Ponder 1984||Shell: minute, conic to ovate-conic, rather solid, non-umbilicate to narrowly umbilicate, smooth or with fine spiral sculpture, aperture with simple peristome, oval, with weak posterior angulation but no channel. Outer lip orthocline with weak to moderate external varix (Fig. 121A, F). Protoconch dome-shaped, of about 1 Yz whorls, smooth except for a weak spiral cord on last Y2 whorl; growth lines strongly curved in sinusigera form (Fig. 121B, H).|