Camya Temporal range: | |
---|---|
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Bivalvia |
Order: | † Fordillida |
Family: | † Camyidae |
Genus: | † Camya |
Species: | †C. asy |
Binomial name | |
†Camya asy Hinz-Schallreuter, 1995 | |
Camya is an extinct genus of early bivalve [1] and is the only genus in the extinct family Camyidae. [2] The genus is known solely from early Middle Cambrian fossils found in Europe. [2] The genus currently contains a solitary accepted species, Camya asy. [2]
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 of each being recovered. The fossils were found in sediments of the middle Cambrian aged Exsulans limestone which outcrops on the island of Bornholm 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. [2] 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. [2]
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. [3] As of 2011 the family has been placed as a sister taxon to the family Fordillidae in the Superfamily Fordilloidea. [1] This superfamily includes the earliest confirmed crown group bivalves to have been described. [2] Camya is one of only four accepted bivalve genera to have been described from the Cambrian, the other three being Fordilla , Pojetaia , and Tuarangia . [2]
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. Bivalves as a group have no head and they lack some usual molluscan organs like the radula and the odontophore. They include the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim. The shipworms bore into wood, clay, or stone and live inside these substances.
Venerida is an order of mostly saltwater but also some freshwater bivalve molluscs. This order includes many familiar groups such as many clams that are valued for food and a number of freshwater bivalves.
The Pteriomorphia comprise a subclass of saltwater clams, marine bivalve molluscs. It contains several major orders, including the Arcida, Ostreida, Pectinida, Limida, Mytilida, and Pteriida. It also contains some extinct and probably basal families, such as the Evyanidae, Colpomyidae, Bakevelliidae, Cassianellidae, and Lithiotidae.
Trigoniidae is a taxonomic family of saltwater clams, marine bivalve mollusks in the superfamily Trigonioidea. There is only one living genus, Neotrigonia, but in the geological past this family was well represented, widespread and common. The shells of species in this family are morphologically unusual, with very elaborate hinge teeth, and the exterior of the shell is highly ornamented.
Praenuculidae is an extinct family of prehistoric bivalves in the superfamily Nuculoidea. Praenuculidae species lived from the early Ordovician, Arenig stage through the Early Devonian Emsian stage. Praenuculidae fossils are found worldwide, present on every continent except Antarctica. Species in this family are thought to have been sessile, attached to the substrate in shallow infaunal marine water environments, where they formed shells of an aragonite composition. The family Praenuculidae was named by A. Lee McAlester in 1969.
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda. The members are known as molluscs or mollusks. Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied.
Anabarella is a species of bilaterally-flattened monoplacophoran mollusc, with a morphological similarity to the rostroconchs. Its shell preserves evidence of three mineralogical textures on its outer surface: it is polygonal near the crest of the shell, subsequently changing to both spiny and stepwise. Its internal microstructure is calcitic and semi-nacreous. Its name reflects its provenance from Anabar, Siberia. It has been interpreted as ancestral to the rostroconchs, and has been aligned to the Helcionellidae.
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. The genus currently contains three described species, Fordilla germanica, Fordilla sibirica, and the type species Fordilla troyensis.
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. The genus currently contains two accepted species, Pojetaia runnegari, the type species, and Pojetaia sarhroensis, though up to seven species have been proposed. The genera Buluniella, Jellia, and Oryzoconcha are all considered synonyms of Pojetaia.
Watsonella is a genus of 'mollusc' known from early (Terreneuvian) Cambrian strata.
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, Asia, and Australia. The family currently contains two genera, Fordilla and Pojetaia, each with up to three described species. Due to the size and age of the fossil specimens, Fordillidae species are included as part of the Turkish Small shelly fauna.
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 found in North America, Greenland, Europe, the Middle East, Asia, and Australia. Fordillidae currently contains two genera, Fordilla and Pojetaia each with up to three described species while Camyidae only contains a single genus Camya with one described species, Camya asy. Due to the size and age of the fossil specimens, Fordillidae species are included as part of the Turkish Small shelly fauna.
Tuarangia is a Cambrian shelly fossil interpreted as an early bivalve, though alternative classifications have been proposed and its systematic position remains controversial. It is the only genus in the extinct family Tuarangiidae and order Tuarangiida. The genus is known solely from Middle to Late Cambrian fossils found in Europe and New Zealand. The genus currently contains two accepted species, Tuarangia gravgaerdensis and the type species Tuarangia paparua.
Concavodonta is an extinct genus of early bivalve in the extinct family Praenuculidae. The genus is one of three genera in the subfamily Concavodontinae. Concavodonta is known solely from late Ordovician, Caradoc epoch, fossils found in Europe and South America. The genus currently contains three accepted species, Concavodonta imbricata, Concavodonta ovalis and the type species Concavodonta ponderata.
Concavodontinae is an extinct subfamily of prehistoric bivalves in the family Praenuculidae. Concavodontinae species lived from the middle Ordovician, Caradoc epoch through the late Ordovician Ashgill epoch. Concavodontinae fossils are found in Europe and South America, and species are thought to have been stationary attached to substrate in shallow infaunal marine water environments where they formed shells of an aragonite composition. The subfamily Concavodontinae was named by Teresa M. Sánchez in 1999.
Praenuculinae is an extinct subfamily of prehistoric bivalves in the family Praenuculidae. Praenuculinae species lived from the middle Ordovician through the late Devonian. Praenuculinae fossils are found in Europe, Africa, North America and South America, and species are thought to have been stationary attached to substrate in shallow infaunal marine water environments where they formed shells of an aragonite composition. The subfamily Praenuculinae was named by Teresa M. Sánchez in 1999.
Trigonoconcha is an extinct genus of bivalve in the extinct family Praenuculidae. The genus is one of eleven genera in the subfamily Praenuculinae. It is one of three Praenuculinae genera known solely from Late Ordivician, Caradoc epoch, fossils found in South America. Trigonoconcha currently contains a single accepted species, Trigonoconcha acuta.
Similodonta is an extinct genus of early bivalve in the extinct family Praenuculidae. The genus is one of eleven genera in the subfamily Praenuculinae. Similodonta is known from Middle Ordovician through Middle Silurian fossils found in Europe and North America. The genus currently contains eight accepted species, Similodonta ceryx, Similodonta collina, Similodonta djupvikensis, Similodonta magna, Similodonta recurva, Similodonta spjeldnaesi, Similodonta wahli and the type species Similodonta similis.
Neotrigonia margaritacea, common name the pearly brooch-shell, is a species of saltwater clam, a marine bivalve mollusc in the family Trigoniidae. This species is known from sandy substrates in shallow seas in southeastern and southwestern Australia. This species was the first member of the family to be discovered alive; previous to its discovery, trigoniids were only known from fossils.
Gigantopecten is a genus of fossil scallops, marine bivalve molluscs in the family Pectinidae, the scallops.