Umbraculida

Umbraculoidea
A live individual of Tylodina perversa in situ
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
(unranked):	clade Heterobranchia clade Euthyneura clade Euopisthobranchia clade Umbraculida
Superfamily:	Umbraculoidea Dall, 1889 (1827)
Superfamilies
See text

See text

Umbraculoidea is a superfamily of unusual false limpets with a thin soft patelliform shell, marine gastropod molluscs in the clade Umbraculida, within the clade Euopisthobranchia.

There are two families in this superfamily, which is listed as the only superfamily in the clade Umbraculida within the informal group Opisthobranchia in the taxonomy of Bouchet & Rocroi (2005).

A study by Grande et al., published in 2004, concluded that Umbraculoidea was a sister clade to the Cephalaspidea (Acteonoidea excluded).

Umbraculoidea contains two families:

Jörger et al. (2010) moved Umbraculoidea to the Euopisthobranchia.

...
Wikipedia