Brachiopod families

The Craniidae are a family of brachiopods, the only surviving members of the subphylum Craniiformea. They are the only members of the order Craniida, the monotypic suborder Craniidina, and the superfamily Cranioidea; consequently, the latter two taxa are at present redundant and rarely used. There are three living genera within Craniidae: Neoancistrocrania, Novocrania, and Valdiviathyris. As adults, craniids either live freely on the ocean floor or, more commonly, cement themselves onto a hard object with all or part of the ventral valve.

Terebratulidae is a family of brachiopods with a fossil record dating back to the Late Devonian. It is subdivided into 11 subfamilies.

Terebratellidae is an extant family of brachiopods with a fossil record dating back to the Jurassic.

Dallinidae is a family of loopbearing brachiopods belonging to the order Terebratulida.

Platidiidae is a family of brachiopods belonging to the order Terebratulida.

Frieleiidae is a family of brachiopods belonging to the order Rhynchonellida.

Discinidae is a family in the brachiopod superfamily Discinoidea. Unlike most brachiopods, which have uniformly calcitic or phosphatic shells, modern-day discinids incorporate tablets of silica into their valves. These are covered with vesicles into which the siliceous tablets are cemented, much like a closely packed mosaic, and held together with apatite. These vesicles eventually degrade, but nevertheless still leave an imprint on the shell itself. It has been suggested that this siliceous biomineralisation might also have occurred amongst some of the earliest Paleozoic brachiopods because s

Hemithirididae is a family of brachiopods belonging to the order Rhynchonellida.