''Cuyopsis'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus of

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

in the

family Praenuculidae. The genus is one of eleven genera in the subfamily

Praenuculinae Praenuculinae is an extinct subfamily of prehistoric bivalves in the family Praenuculidae. Praenuculinae species lived from the middle Ordovician through the late Devonian.

. It is one of three Praenuculinae genera known solely from late Ordivician, Caradoc epoch, fossils found in South America. ''Cuyopsis'' currently contains a

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accepted species, ''Cuyopsis symmetricus''.

Description

''Cuyopsis symmetricus'' was first described in 1999 by Teresa M. Sánchez from fossils in sediments of the late Middle Ordivician, Caradocian aged Don Braulio Formation. The formation outcrops on the flank of Sierra de Villicum in the Argentina

precordillera Precordillera is a Spanish geographical term for hills and mountains lying before a greater range, foothills. The term is derived from ''cordillera'' (mountain range)—literally "pre-mountain range"—and applied usually to the Andes. Some places ...

.The Paleobiology database "Sierra de Villicum" entry
accessed 5 February 2012 Generally the shells of ''Cuyopsis symmetricus'' are rectangular in outline and notably symmetrical. The shells have an umbo positioned centrally on the rear edge of the shell, with the umbo beak being orthogyrate, thus curving downwards perpendicular to the hinge. The shell hinges have a series of eleven convexodont teeth along the posterior edge and a series of ten convexodont teeth on the anterior edge and the two series meet at the umbo. ''C. symmetricus'' ranges in shell length from and has a height between . As a member of Praenuculinae, the hinge displays the chevroning of teeth typical of the subfamily. The teeth have a concavity in the chevron facing towards the center of the hinge and the umbo. When described, the genus name ''Cuyopsis'' was chosen by Sánchez in reference to the Cuyo region where the type locality is. The species epithet ''symmetricus'' was coined as a reference to the notably symmetrical nature of the valves.

References

{{Taxonbar, from=Q5197106 Praenuculidae Ordovician bivalves Ordovician animals of South America Ordovician Argentina Fossil taxa described in 1999 Prehistoric bivalve genera