Monoplacophora, meaning "bearing one plate", is a polyphyletic superclass of molluscs with a cap-like shell now living at the bottom of the deep sea. Extant representatives were unknown until 1952; previously they were known only from the fossil record.

Monoplacophora, meaning "bearing one plate", is a polyphyletic superclass of molluscs with a cap-like shell now living at the bottom of the deep sea. Extant representatives were unknown until 1952; previously they were known only from the fossil record.