|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Helcionelloida - Helcionellida - Helcionellidae
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.
|A. Kouchinsky et al. 2011||"Internal moulds triangular in lateral view with apex sub-central or slightly inclined, moderately compressed laterally, surface with strong concentric ribs that may alternate on the narrow sides, aperture elliptical (modified from Geyer 1986, p. 84, Bengtson et al. 1990, p. 234 and Parkhaev, 2005, p. 618)."|