Rhynchonellata

thumb|A modern member of Rhynchonellata, Calloria inconspicua, observed off the coast of New Zealand The Rhynchonellata is a class of Lower Cambrian to Recent articulate brachiopods that combines orders from within the Rhynchonelliformea (Articulata revised) with well developed pedicle attachment. Shell forms vary from those with wide hinge lines to beaked forms with virtually no hinge line and from generally smooth to strongly plicate. Most all are biconvex. Lophophores vary and include both looped and spiraled forms. Although morphologically distinct, included orders follow a consistent phyl

Atrypa is a genus of brachiopod with round to short egg-shaped shells covered with many fine radial ridges (or costae). Growth lines form perpendicular to the costae and are spaced approximately 2 to 3 times further apart than the costae.. The pedunculate valve is slightly convex, but oftentimes levels out or becomes slightly concave toward the anterior margin (opposite the hinge and pedicle). The brachial valve is highly convex. Neither valve contains an interarea (a flat area bordering the hinge line, approximately perpendicular with the rest of the valve). Atrypa had a large geographic rang

Platystrophia is an extinct genus of brachiopods that lived from the Ordovician to the Silurian in Asia, Europe, North America, and South America. It has a prominent sulcus and fold. It usually lived in marine lime mud and sands.

Thecideida is an order of cryptic articulate brachiopods characterized by their small size and habit of cementing their ventral valves to hard substrates such as shells, rocks and carbonate hardgrounds. Thecideides first appeared in the Triassic and are common today. thumb|Thecidium mediterraneum, A. natural size: B. section through shell (magnified)

Atrypida is an extinct order of rhynchonelliform brachiopods. They first appeared in middle Ordovician and survived the Ordovician-Silurian extinction, becoming the dominant brachiopods of the Silurian alongside the order Pentamerida. They would survive into the Late Devonian before going extinct at the end of the Frasnian (Late Devonian).

Pentamerida is an order of biconvex, impunctate shelled, articulate brachiopods that are found in marine sedimentary rocks that range from the Middle Cambrian through the Devonian.

The gall mite genus Pentamerus, established by Roivainen in 1951, is invalid and needs to be renamed. Until this happens, use Pentamerus (mite).

Athyridida is an order of Paleozoic brachiopods included in the Rhynchonellata, which makes up part of the articulate brachiopods.

Spiriferinida is an extinct brachiopod order, known from the Devonian to the Jurassic.