''Cyrtospirifer'' is an extinct genus of

brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, w ...

s. The fossils are present in the Middle and Upper Devonian.

Taxonomy

It is likely that ''Tenticospirifer'', that itself appeared during early Givetian, includes the ancestor of ''Cyrtospirifer''. ''Cyrtospirifer'' first occurs in western Europe in the Late Givetian. ''Tenticospirifer'' has a relatively narrow hinge line and an inflated and thick shell in common with two of the oldest species known, ''C. verneuiliformis'' and ''C. aperturatus''. This group dominated during the late Givetian, but was replaced by other species, such as ''C. syringothyriformis'' and ''C. verneuili'' which have wide hinge lines and thinner shells.

Description

''Cyrtospirifer'' has a medium to large sized shell, wider than long. File:Cyrtospirifer verneuili brachial valve.jpg, ''Cyrtospirifer verneuili'', 24mm long and about 60mm wide, brachial valve File:Cyrtospirifer verneuili pedunculate valve.jpg, pedicle valve File:Cyrtospirifer verneuili lateral.jpg, lateral File:Cyrtospirifer verneuili hinge.jpg, posterior File:Cyrtospirifer verneuili opening oblique.jpg, anterior

Reassigned species

* ''C. glaucus'' = '' Regelia glauca''

References

Prehistoric brachiopod genera Devonian brachiopods Fossils of Belgium Middle Devonian first appearances Famennian extinctions Spiriferida Paleozoic life of Alberta Paleozoic life of the Northwest Territories {{Brachiopod-stub