|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||Age range and collections|
It was assigned to Hyolithida by Brock and Cooper (1993), Sepkoski (2002) and Malinky and Skovsted (2004).
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.
|J. M. Malinky and C.B. Skovsted 2004||Diagnosis.—Conchs with ovoid cross−section and ventrally
directed longitudinal curvature. Ligula semi−elliptical, at 120°
to dorsal apertural margin. Surface sculpture of distinct
growth lines and faint longitudinal striations. Opercula with
broad cardinal shield, well−defined tectula, cardinal processes
about 3 lengths of the operculum width, thickened central field
on inner surface, and no clavicles (from Bengtson 1990a).