Inarticulata was historically defined as one of the two classes of the phylum Brachiopoda and referred to those having no hinge. The other class was Articulata, meaning articulated – having a hinge between the dorsal and ventral valves. These classifications have now been superseded, see brachiopod classification.
This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press.