Exogyra

Exogyra; Temporal range: Jurassic–Cretaceous PreꞒ Ꞓ O S D C P T J K Pg N
	Exogyra flabellata ; (Owl Creek Formation, Late Cretaceous, Mississippi)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Order:	Ostreida
Family:	Gryphaeidae
Genus:	†Exogyra; Say, 1820
Species
	See text

Exogyra is an extinct genus of fossil marine oysters in the family Gryphaeidae, the foam oysters or honeycomb oysters.^[1] These bivalves were 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^{[citation needed]} during the Jurassic and Cretaceous periods.^[2]

Taxonomy

The former subgenus Exogyra (Aetostreon) Bayle, 1878,^[3] 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).^[4]

Species

Exogyra costata, Prairie Bluff Chalk Formation (Maastrichtian); Starkville, Mississippi

Exogyra (subgenus Exogyra) (Say, 1820)

Exogyra africana Say, 1820^[5]
Exogyra aquillana Stephenson, 1953
Exogyra arietina Roemer, 1849^[6]
Exogyra callophyla Ihering, 1903
Exogyra cancellata Stephenson, 1914
Exogyra clarki Shattuck, 1903
Exogyra columbella Meek, 1876
Exogyra contorta Eichwald, 1868
Exogyra costata Say, 1971
Exogyra davidsoni Whidborne, 1883 ^[7]
Exogyra erraticostata Stephenson^[8]
Exogyra fimbriata Conrad, 1855
Exogyra flabellata (Goldfuss, 1833)
Exogyra ganhamoroba Maury, 1936
Exogyra guadalupae Whitney, 1937 (thesis)
Exogyra haliotoidea Maury, 1936
Exogyra laevigata J. de C. Sowerby, 1829 ^[9]
Exogyra laeviuscula Roemer, 1849
Exogyra lancha Stoyanow, 1949
Exogyra levis Stephenson, 1952
Exogyra mutatoria White, 1887
Exogyra paupercula Cragin, 1893
Exogyra plexa Cragin, 1893
Exogyra potosina Castillo and Aguilera, 1895
Exogyra ponderosa Roemer, 1849
Exogyra praevirgula Douville & Jourdy, 1924^[10]^[11]
Exogyra quitmanensis Cragin, 1893
Exogyra sergipensis Maury, 1936
Exogyra sigmoidea Reuss, 1844^[12]
Exogyra solea Muller, 1910
Exogyra texana Roemer, 1849
Exogyra upatoiensis Stephenson, 1914
Exogyra whitneyi Bose, 1910
Exogyra woolmani Richards, 1947

Distribution

Fossils of Exogyra have been found in:^[2]

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 Formations, Eastern Ranges),^[13]^[14] Cuba, the Czech Republic, Egypt, Ethiopia, France, Germany, Greenland, Hungary, India, Iran, Israel, 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

^ "Evolution of Exogyra plexa". Archived from the original on 26 March 2008. Retrieved 25 March 2008.
^ ^a ^b Exogyra at Fossilworks.org
^ "†Exogyra (Aetostreon) Bayle 1878". Paleobiology Database. Fossilworks. Archived from the original on 13 December 2021. Retrieved 17 December 2021.
^ Pugaczewska, Halina (1975). "Neocomian oysters from Central Poland" (PDF). Acta Palaeontologica Polonica. 20 (1): 47–72.
^ Exogyra africana
^ Roemer, F. (1849). Texas mit besonderer Rücksicht auf deutsche Auswanderung und die physischen Verhältnisse des Landes nach eigener Beobachtung. A. Marcus.
^ Exogyra davidsoni at Fossilworks.org
^ Exogyra
^ Lake.P., and Rastall.R.H., (1913), A Text Book of Geology, 2nd edition, London: Edward Arnold's Geological series Page 426 and 436
^ Exogyra praevirgula
^ "Global Names Index". Archived from the original on 6 November 2014. Retrieved 5 November 2014.
^ Ivanov. M., Hrdlickova. S., and Gregorova. R., (2005), The Complete Encyclopedia of Fossils, 3rd. ed., Lisse: Rebo International, page 133
^ Piraquive et al., 2011, p. 204
^ Acosta & Ulloa, 2002, p. 54

Bibliography

Acosta, Jorge E.; Ulloa, Carlos E. (2002), Mapa geológico del Departamento de Cundinamarca 1:250,000 - Memoria Explicativa, Colombian Geological Survey, pp. 1–108
Piraquive, Alejandro; Díaz, Juan Sebastián; Cuéllar, Tomas; Pardo, Germán; Kammer, Andreas (2011), "Reactivación Neógena de estructuras de rift del Cretácico Temprano asociadas con la Falla de Chámeza, Pajarito, Boyacá (Colombia): evidencias tectónicas y bioestratigráficas" (PDF), Geología Colombiana, 36: 197–216, archived from the original (PDF) on 30 March 2017, retrieved 4 August 2017