|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Helcionelloida - Helcionellida - Helcionellidae
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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.
|P. Y. Parkhaev and Y. Demidenko 2010||"Shell cap-shaped, low conical, elongated to different extent. Apex hooked downwards and displaced posteriorly, projecting over posterior apertural margin. Anterior field evenly convex, becomes gently convex near aperture. Posterior field very short, concave below apex, flattens towards aperture. Lateral fields moderately convex. Aperture irregularly oval or pyriform, its posterolateral flanks slightly pulled, forming small 'auricles'. Posterior apertural margin with subapical angulation. Exterior shell ornamentation represented by growth lines. Surface of internal mold smooth or with concentric wrinkles."|