Septemchitonidae is an extinct family of

chitons Chitons () are marine (ocean), marine molluscs of varying size in the class (biology), class Polyplacophora ( ), formerly known as Amphineura. About 940 Extant taxon, extant and 430 fossil species are recognized. They are also sometimes known ...

(Polyplacophora) known from Europe and North America. Morphologically, the

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

is defined by rectangular plates, and the upside-down V-shape of species' valves when viewed in cross-section.

References

{{Taxonbar, from=Q21590441 Prehistoric chiton families