''Exogyra'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

marine oysters in the family Gryphaeidae, the foam oysters or honeycomb oysters. These bivalves grew cemented by the more cupped left valve. The right valve is flatter, and the beak is curved to one side. ''Exogyra'' lived on solid substrates in warm seas during the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

and

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

periods.

Taxonomy

The former

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed betw ...

''Exogyra'' (''

Aetostreon ''Aetostreon'' is an extinct genus or subgenus within the genus ''Exogyra'' of fossil marine oysters in the family Gryphaeidae The Gryphaeidae, common name the foam oysters or honeycomb oysters, are a family of marine bivalve mollusks. This ...

'') Bayle, 1878 is sometimes considered a separate genus, due to a lack of the fine set of parallel ribs (chomata) separated by pits, on the inner surface of the valves (which is present in the nominate subgenus).

Species

Exogyra costata Prairie Bluff Fm Maastrichtian

Distribution

Fossils of ''Exogyra'' have been found in:''Exogyra''
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cre ...

.org ;Jurassic Afghanistan, Chile, China, Eritrea, Ethiopia, France, Germany, India, Kenya, Poland, Portugal, Somalia, Spain, Tanzania, the United Kingdom, and Yemen. ;Cretaceous Afghanistan, Algeria, Argentina, Brazil, Bolivia, Canada (British Columbia), Bulgaria, Chile, Colombia ( Hiló Formation, Tolima, Macanal and

Chipaque Formation The Chipaque Formation ( es, Formación Chipaque, K2cp, Kc) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation is also described as Gachetá Formation, named after Gachetá, in the area o ...

Eastern Ranges The Eastern Ranges is an Australian rules football team in the NAB League, the Victorian statewide under-18s competition. The club is a founding member of the competition (1992) and has produced several players for the Australian Football Le ...

),Acosta & Ulloa, 2002, p. 54 Cuba, the Czech Republic, Egypt, Ethiopia, France, Germany, Greenland, Hungary, India, Iran, Italy, Jordan, Lebanon, Libya, Madagascar, Mexico, Morocco, Mozambique, New Zealand, Nigeria, Oman, Pakistan, Peru, Poland, Portugal, Serbia and Montenegro, Slovakia, South Africa, Spain, Sweden, Switzerland, Tanzania, Trinidad and Tobago, Tunisia, Turkey, USSR, Ukraine, the United Kingdom, United States (Alabama, Arizona, Arkansas, California, Colorado, Delaware, Georgia, Maryland, Minnesota, Mississippi, Missouri, Montana, New Jersey, New Mexico, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Utah, Wyoming), Venezuela, and Yemen.

References

Bibliography

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Taxonomy

Species

Distribution

References

Bibliography

Further reading