Exogyra

Last updated

Exogyra
Temporal range: Jurassic–Cretaceous
Exogyracostata.JPG
Exogyra flabellata
(Owl Creek Formation, Late Cretaceous, Mississippi)
Scientific classification OOjs UI icon edit-ltr.svg
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]

Contents

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 costata Prairie Bluff Fm Maastrichtian.JPG
Exogyra costata, Prairie Bluff Chalk Formation (Maastrichtian); Starkville, Mississippi
Exogyra (subgenus Exogyra) (Say, 1820)

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), [12] [13] 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.

Related Research Articles

<i>Inoceramus</i> Extinct genus of bivalves

Inoceramus is an extinct genus of fossil marine pteriomorphian bivalves that superficially resembled the related winged pearly oysters of the extant genus Pteria. They lived from the Early Jurassic to latest Cretaceous.

<i>Berriasella</i> Genus of molluscs (fossil)

Berriasella is a discoidal evolute perisphinctacean ammonite, and type genus for the neocomitid subfamily Berriasellinae. Its ribbing is distinct, consisting of both simple and bifurcated ribs that extend from the umbilical seam across the venter; its whorl section generally compressed, the venter more or less narrowly rounded. The species Berriasella jacobi traditionally has been regarded an index fossil defining the base of the Cretaceous, however since 2016 this had been replaced by the first occurrence of Calpionella alpina. Some authors regard B. jacobi as instead belonging to the genus Strambergella.

<span class="mw-page-title-main">Gryphaeidae</span> Family of bivalves

The Gryphaeidae, common name the foam oysters or honeycomb oysters, are a family of marine bivalve mollusks. This family of bivalves is very well represented in the fossil record, however the number of living species is very few.

<i>Pycnodonte</i> Extinct genus of bivalves

Pycnodonte is a genus of extinct oysters, fossil marine bivalve mollusks in the family Gryphaeidae, the foam oysters or honeycomb oysters. Shells of species in this genus are found around the world in fossil shell beds from the Valanginian to the Early Pleistocene. They are a commonly found fossil in Cretaceous shellbeds of the Navesink Formation in New Jersey.

<i>Aetostreon</i> Extinct genus of bivalves

Aetostreon is an extinct genus or subgenus within the genus Exogyra of fossil marine oysters in the family Gryphaeidae.

<i>Trigonia</i> Extinct genus of bivalves

Trigonia is an extinct genus of saltwater clams, fossil marine bivalve mollusk in the family Trigoniidae. The fossil range of the genus spans the Paleozoic, Mesozoic and Paleocene of the Cenozoic, from 298 to 56 Ma.

<i>Olcostephanus</i> Genus of molluscs (fossil)

Olcostephanus is an extinct ammonoid cephalopod genus belonging to the family Olcostephanidae. These fast-moving nektonic carnivores lived during the Cretaceous, from the upper Valanginian to the lower Hauterivian age.

<span class="mw-page-title-main">La Frontera Formation</span> Geological formation

The La Frontera Formation (Spanish: Formación La Frontera, K2F, Ksf) is a geological formation, part of the Villeta Group, of the Altiplano Cundiboyacense and neighbouring areas of the Eastern Ranges of the Colombian Andes. The sequence of limestones and lydites dates to the Late Cretaceous period; Turonian epoch and has a maximum thickness of 206 metres (676 ft).

<span class="mw-page-title-main">Conejo Formation</span> Fossiliferous geological formation in the Eastern Ranges of the Colombian Andes

The Conejo Formation (Spanish: Formación Conejo, K2C, Kscn) is a fossiliferous geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The uppermost unit of the Villeta Group, a sequence of shales and sandstones dates to the Late Cretaceous period; Turonian, Coniacian and Santonian epochs, and has a maximum thickness of 1,022 metres (3,353 ft).

The Murca Formation is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The predominantly subarkose sandstone with claystones and siltstones formation dates to the Early Cretaceous period; Valanginian epoch and has a maximum thickness of 924 metres (3,031 ft).

<span class="mw-page-title-main">Hiló Formation</span> Geological formation in the Colombian Andes

The Hiló Formation is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The predominantly shale formation dates to the Middle Cretaceous period; Late Albian to Early Cenomanian epochs and has a measured thickness at its type section of 470 metres (1,540 ft). The fossiliferous formation has provided a great abundance of ammonites and other marine species.

<span class="mw-page-title-main">El Peñón Formation</span>

The El Peñón Formation is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consists of calcareous shales and siltstones and dates to the Early Cretaceous period; Late Aptian epoch and has a measured thickness at its type section of 381 metres (1,250 ft). Ammonite fossils have been found in the formation, deposited in a shallow marine platform environment.

<span class="mw-page-title-main">Macanal Formation</span>

The Macanal Formation or Macanal Shale is a fossiliferous geological formation of the Altiplano Cundiboyacense and Tenza Valley in the Eastern Ranges of the Colombian Andes. The predominantly organic shale formation dates to the Early Cretaceous period; Berriasian to Valanginian epochs and has a maximum thickness of 2,935 metres (9,629 ft). The Macanal Formation contains numerous levels of fossiliferous abundances. Bivalves, ammonites and fossil flora have been found in the formation.

<span class="mw-page-title-main">Guavio Formation</span>

The Guavio Formation is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consists of conglomerates, shales and limestones, dates to the Late Jurassic and Early Cretaceous periods; Tithonian to Berriasian epochs and has a maximum thickness of 1,000 metres (3,300 ft).

<span class="mw-page-title-main">Hondita Formation</span> Fossiliferous geological formation of the Colombian Andes

The Hondita Formation is a fossiliferous geological formation of the Upper Magdalena Valley (VSM) and surrounding Central and Eastern Ranges of the Colombian Andes, extending from Cundinamarca in the north to Huila and easternmost Tolima in the south. The lowermost unit of the Güagüaquí Group, a sequence of sandy limestones and shales, dates to the Late Cretaceous period; Turonian epoch, and has a maximum thickness of 90 metres (300 ft).

<span class="mw-page-title-main">Oliní Group</span> Fossiliferous geological group

The Oliní Group (Spanish: Grupo Oliní, K3k5o, K2ol, Kso) is a fossiliferous geological group of the VMM, VSM and the eastern flanks of the Central and western flanks of the Eastern Ranges of the Colombian Andes. The regional group stretches from north to south across approximately 700 kilometres (430 mi) and dates to the Late Cretaceous period; Coniacian, Santonian and Campanian epochs, and has a maximum thickness of 287 metres (942 ft). Fossils of Eonatator coellensis have been found in the unit, near Coello, Tolima.

The Chachao Formation is a geological formation in the Mendoza Province in northern Patagonian Argentina. It is Valanginian in age and is predominantly marine, being deposited at a time of marine transgression in the Neuquén Basin, and predominantly consists of carbonate rocks.

<i>Texigryphaea</i> Extinct genus of oyster

Texigryphaea is an extinct genus of oyster belonging to the order Ostreida and family Gryphaeidae. It dates to the Albian to Cenomanian Ages of the Cretaceous period and is primarily found in Texas and the southern Western Interior of North America. However, specimens have been identified from northern Spain.

<i>Rastellum</i>

Rastellum is an extinct genus of molluscs, which lived from the Middle Jurassic to the Late Cretaceous. This species is also known as Arctostrea carinata.

References

  1. ↑ "Evolution of Exogyra plexa". Archived from the original on 26 March 2008. Retrieved 25 March 2008.
  2. 1 2 Exogyra at Fossilworks.org
  3. ↑ "†Exogyra (Aetostreon) Bayle 1878". Paleobiology Database. Fossilworks. Retrieved 17 December 2021.
  4. ↑ Pugaczewska, Halina (1975). "Neocomian oysters from Central Poland" (PDF). Acta Palaeontologica Polonica. 20 (1): 47–72.
  5. ↑ Exogyra africana
  6. ↑ Exogyra davidsoni at Fossilworks.org
  7. ↑ Exogyra
  8. ↑ Lake.P., and Rastall.R.H., (1913), A Text Book of Geology, 2nd edition, London: Edward Arnold's Geological series Page 426 and 436
  9. ↑ Exogyra praevirgula
  10. ↑ Global Names Index
  11. ↑ Ivanov. M., Hrdlickova. S., and Gregorova. R., (2005), The Complete Encyclopedia of Fossils, 3rd. ed., Lisse: Rebo International, page 133
  12. ↑ Piraquive et al., 2011, p. 204
  13. ↑ Acosta & Ulloa, 2002, p. 54

Bibliography

Further reading


This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.