''Camya'' 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 Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of early

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 ...

and is the only genus in the extinct family Camyidae. The genus is known solely from early Middle Cambrian fossils found in Europe. The genus currently contains a

solitary Solitary is the state of being alone or in solitude. The term may refer to: * shortened form of solitary confinement * Solitary animal, an animal that does not live with others in its species * Solitary but social, a type of social organization in ...

accepted species, ''Camya asy''.

Description

''Camya asy'' is a small bivalve which was first described in 1995 by Ingelore Hinz-Schallreuter. The genus and species are based on the fossils of two juvenile specimens which are both incomplete due to only the left

valve A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fittings ...

of each being recovered. The fossils were found in sediments of the middle Cambrian aged ''Exsulans'' limestone which outcrops on the island of

Bornholm Bornholm () is a Danish island in the Baltic Sea, to the east of the rest of Denmark, south of Sweden, northeast of Germany and north of Poland. Strategically located, Bornholm has been fought over for centuries. It has usually been ruled by ...

in the Baltic Sea. The valves have a distinct subtriangular shape and possess a long straight hinge. The umbo is positioned notably anterior on the shell and the beak is bracketed by two teeth of indistinctly pyramidal shape. The presence of the teeth was later questioned in a 1998 study by G. Geyer and M. Streng and cited the lack of preserved muscle scars as reason to suspect the placement of ''Camya asy'' in Bivalvia. The family Camyidae was first proposed by Hinz-Schallreuter in a 2000 paper discussing the Cambrian bivalves from Bornholm and reviewing the proposed Cambrian bivalve taxa of the time. In the same paper, Hinz-Schallreuter noted that the species ''Modiolopsis thecoides'', known from one specimen which is now lost, most likely belonged to ''Camya''. As of 2011 the family has been placed as a sister taxon to the family

Fordillidae Fordillidae is an extinct family of early bivalves and one of two families in the extinct superfamily Fordilloidea. The family is known from fossils of early to middle Cambrian age found in North America, Greenland, Europe, the Middle East, A ...

in the Superfamily

Fordilloidea Fordilloidea is an extinct superfamily of early bivalves containing two described families, Fordillidae and Camyidae and the only superfamily in the order Fordillida. The superfamily is known from fossils of early to middle Cambrian age fo ...

. This superfamily includes the earliest confirmed crown group bivalves to have been described. ''Camya'' is one of only four accepted bivalve genera to have been described from the Cambrian, the other three being ''

Fordilla ''Fordilla'' is an extinct genus of early bivalves, one of two genera in the extinct family Fordillidae. The genus is known solely from Early Cambrian fossils found in North America, Greenland, Europe, the Middle East, and Asia.Pojetaia ''Pojetaia'' is an extinct genus of early bivalves, one of two genera in the extinct family Fordillidae. The genus is known solely from Early to Middle Cambrian fossils found in North America, Greenland, Europe, North Africa, Asia, and Australia ...

'', and ''

Tuarangia ''Tuarangia'' is a Cambrian shelly fossil interpreted as an early bivalve, though alternative classifications have been proposed and its systematic position remains controversial.Elicki, O., & Gürsu, S. (2009). First record of ~Pojetaia runnegar ...

''.

References

Prehistoric bivalve genera Cambrian molluscs Prehistoric life of Europe Fossil taxa described in 1995 Fossil taxa described in 2000 Monotypic mollusc genera {{paleo-bivalve-stub