Athyridida is an order of Paleozoic brachiopods included in the

Rhynchonellata The Rhynchonellata is a class of Lower Cambrian to Holocene, Recent Articulata (Brachiopoda), articulate brachiopods that combines orders from within the Rhynchonelliformea (Articulata revised) with well developed pedicle attachment. Shell forms ...

, which makes up part of the articulate brachiopods.Athyridida-Paleodb
/ref> The Athyridida are the Rostrospracea of R.C. Moore, 1952,Moore, Lalcker and Fischer, 1952, Invertebrate Fossils, McGraw-Hill considered at that time to be a suborder of the Spiriferida. As with the Spiriferida, the Athyridida have outwardly directed spiral brachidia that support the lophophores on either side, but instead have non-plicate shells with rounded outlines and prominent beaks but almost no inner areas on the pedicle valve. Athyridids began early in the

Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

, reached their greatest diversity in the following

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

, and from then declined steadily until almost becoming

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

at the end of the

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

The order rejuvenated somewhat during the

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

, only to decline again until becoming extinct in the

Early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic� ...

. '' Athyris'', '' Composita'', and '' Meristella'' are representative genera. Three suborders have been defined.

References

Rhynchonellata Prehistoric brachiopod orders {{brachiopod-stub