|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||Age range and collections|
Gastropoda - Architectibranchia - Cylindrobullinidae
It was reranked as Cylindrobullina (Conactaeon) by Haas (1953).
It was assigned to Euconactaeon by Meek (1863); to Cylindrobullina by Haas (1953); to Acteonidae by Fischer et al. (2002); and to Cylindrobullinidae by Gründel and Nützel (2012).
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. Gründel and A. Nützel 2012||The shell is biconical with heterostrophic protoconch. The spire is distinctly elevated and gradate. The whorls have a nearly horizontal subsutural ramp which is demarcated from the flanks by a sharp angulation. The whorls taper abapically so that the base is reversed conical. The flanks are straight to slightly convex. The shell is smooth or has spiral furrows. The aperture is elongated and narrow. It is demarcated by the adapical ramp and somewhat broadened abapically. The shell lacks columellar folds. The growth lines are weakly prosocyrt on the flanks and opisthocyrt on the ramp.|