Cliothyris, Spirithyris, Euthyris, Cleidothyris Athyris is a brachiopod genus with a subequally biconvex shell that is generally wider than long and a range that extends from the Silurian into the Triassic.

Moore (1952) gives a shorter range, from the Mid Devonian to the Lower Mississippian.

Alverezites, Bruntonites, and Meristospira are among related genera.

Some species originally included in Athyris have been reassigned.

[1] Composition: low Mg calcite Entire body: yes Adult length: 10 to < 100 Adult width: 10 to < 100 Adult height: 10 to < 100 Folds: minor Ribbing: minor Spines: none Internal reinforcement: none Locomotion: stationary Attached: yes Life habit: low-level epifaunal Diet: suspension feeder Vision: blind References: Aberhan et al. 2004, Hendy 2009