Topaginella

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Topaginella
Fossil range: Miocene

Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Orthogastropoda
Superorder:	Caenogastropoda
Order:	Sorbeoconcha
Suborder:	Hypsogastropoda
Infraorder:	Neogastropoda
Superfamily:	Muricoidea
Family:	Cystiscidae
Subfamily:	Cystiscinae
Genus:	Topaginella Laseron, 1957

Topaginella is a genus of minute fossil sea snails, marine gastropod mollusks in the family Cystiscidae. Like all of the related genera, this are sometimes still classified in the family Marginellidae.

This genus is extinct.

(Note: Gastropod taxonomy has been in flux for more than half a century, and this is especially true currently, because of new research in molecular phylogeny. Because of all the on-going changes, different reliable sources can yield very different classifications.)

[edit] Shell description

Shell minute, pyriform, strongly narrowed anteriorly; spire low; lip thickned, strongly denticulate; external varix probably absent (needs to be confirmed); distinct axial costae present; siphonal notch absent; columella multiplicate, with combined total of usually 8 plications plus parietal lirae.

[edit] Type species of the genus Topaginella

Marginela octoplicata Tenison-Woods, 1877 †; OD (M)

Remarks: The type species sems to be unique (a monotypic genus). The multiplicate columella and lack of a siphonal notch place it near Cystiscus, but the pyriform shape, exserted spire, denticulate lip, and fine axial costae render it distinct.