[2] Strophomenida is part of the extinct class Strophomenata, and was the largest known order of brachiopods, encompassing over 400 genera[citation needed].

Survivors rediversified into new morphologies in the Silurian,[3] only to be impacted once again at the Late Devonian mass extinction.

[1] Adult strophomenids lack an opening for the pedicle (stalk), so in life, they either lay free or cemented the ventral valve (lower shell) onto a firm substrate at the umbo (hinge).

In juveniles, a tiny hole for the pedicle was present on the ventral valve near the umbo, but this is closed up through development.

The interior of the valves have a distinctive pseudopunctate microtexture: deflections in the mineralized shell layers stack up and unfurl into tiny bumps, which are usually supported by calcite rods known as a taleolae.