''Camya'' is an
extinct
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of early
bivalve
Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...
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:
* ''Solitary'' (album), 2008 album by Don Dokken
* ''Solitary'' (2020 film), a British sci-fi thriller film
* ''Solitary'' (upcoming film), an American drama film
* "S ...
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 Slurry, slurries) by opening, closing, or partially obstructing various passageways. Valves are technically Pip ...
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 List of islands of Denmark, 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. I ...
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 in the Superfamily
Fordilloidea.
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'', ''
Pojetaia'', and ''
Tuarangia''.
References
Monotypic prehistoric bivalve genera
Cambrian molluscs
Prehistoric life of Europe
Fossil taxa described in 1995
Fossil taxa described in 2000
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