Spiriferinida

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

Description

The order Spiriferinida belongs to the subphylum Rhynchonelliformea, approximately corresponding to the former subphylum Articulata characterised by calcareous shell with teeth and sockets, and to the class Rhynchonellata defined on the basis of the shell microstructure.
The spiriferinides are characterised by a spiralium that is oriented laterally or postero-laterally, the presence of a jugum, and a punctate shell. The two latter characters allow the distinction between the orders Spiriferinida and Spiriferida ; these orders were merged in older brachiopod systems.
The order Spiriferinida is divided into two suborders:

Cyrtinidina Carter & Johnson, 1994, characterised by ventral valves with complex structures serving for the attachment of adductor muscles;
Spiriferinidina Ivanova, 1972, with ventral valves lacking such structures.

Cyrtina is the oldest spiriferinide genus and among the best known representatives of the order. It is known from the Lower Devonian to the Carboniferous from many places in the world. More than a hundred species of Cyrtina have been described.
In the Early Jurassic there were species with strongly costate shells, finely costate shells, and smooth shells. The last spiriferinides are known from the Toarcian.