Conchifera is a subphylum of the phylum Mollusca, containing five extant classes: Monoplacophora, Cephalopoda, Gastropoda, Bivalvia, and Scaphopoda.

The other subphylum is Aculifera, the members of which are shellless or have a row of several plates.

Non-monoplacophoran conchiferans emerged within the once-widespread Monoplacophora.

[clarification needed] The monophyly of Conchifera is supported by molecular phylogenetic analysis.

[1] A grouping of Scaphopoda and Bivalvia, named Diasoma, has been proposed,[2][3] but other studies find scaphopods to be more closely related to cephalopods[4] or gastropods.