Inarticulata (Ecardines; phylum Brachiopoda) A class of brachiopods whose chitinophosphatic or calcareous valves are held together only by muscles and the body wall, and not hinged. The valves may be punctate or impunctate. There is no internal skeletal support for the lophophore. The pedicle is developed from the ventrai mantle. The alimentary canal has a functional anus. Inarticulata first appeared in the Lower Cambrian.

Inarticulata (phylum Brachiopoda) A class of brachiopods, existing from the Lower Cambrian to the present day, in which the shell is calcareous, but its valves are not hinged by teeth and sockets and the pedicle is much reduced or absent. There are 3 orders.

Lingulata (phylum Brachiopoda) A class of brachiopods, existing from the Lower Cambrian to the present day, in which the shell is chitinophosphatic, the valves are not hinged by teeth and sockets, and the pedicle is thick.