Athyridida is an order of Paleozoic brachiopods included in the
Rhynchonellata
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 li ...
, 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
Spiriferida is an order of extinct articulate brachiopod fossils which are known for their long hinge-line, which is often the widest part of the shell. In some genera (e.g. ''Mucrospirifer'') it is greatly elongated, giving them a wing-like app ...
. As with the Spiriferida, the Athyridida have outwardly directed spiral brachidia that support the
lophophore
The lophophore () is a characteristic feeding organ possessed by four major groups of animals: the Brachiopoda, Bryozoa, Hyolitha, and Phoronida, which collectively constitute the protostome group Lophophorata.Silurian, reached their greatest diversity in the following Devonian, and from then declined steadily until almost becoming extinct 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 251.9 Mya. It is the last ...
The order rejuvenated somewhat during the
Triassic
The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 ...
, 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-J ...
.
'' Athyris'', '' Composita'', and '' Meristella'' are representative genera. Three suborders have been defined.