Exogyra

Exogyra
Exogyra flabellata
(Owl Creek Formation, Late Cretaceous, Mississippi)
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Ostreoida
Family: Gryphaeidae
Genus: Exogyra
Species
  • see text

Exogyra is an extinct genus of fossil saltwater oysters, marine bivalve mollusks in the family Gryphaeidae, the foam oysters or honeycomb oysters.[1] 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.

The subgenus Aetostreon 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).[2]

Species

Exogyra (subgenus Exogyra) (Say, 1820)

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

Exogyra (subgenus Aetostreon) (Bayle, 1878)[13]

References

  1. http://crnmac1.physics.uiowa.edu/fossils/oysters/ilymatogyra/Exogyra-plexa.html Evolution of Exogyra plexa
  2. 2.0 2.1 Pewgaczewska.H., (n.d.) http://www.app.pan.pl/archive/published/app20/app20-047.pdf
  3. http://zipcodezoo.com/Animals/E/Exogyra_africana/
  4. http://www.bivatol.org/downloads/Lab_2_Bivalve_Fossil_Record_curriculum.pdf
  5. https://www.wardsci.com/store/catalog/product.jsp?catalog_number=528130
  6. http://fossilworks.org/bridge.pl?a=taxonInfo&taxon_no=304725
  7. http://fossilsofnj.com/invertebrates/exogyra.htm
  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. Castell. C.P., and Cox. L.R., (1975), British Mesozoic Fossils, 5th edition, London: Trustees of the British Museum (Natural History), page 86
  10. http://translate.google.co.uk/translate?hl=en&sl=fr&u=http://science.mnhn.fr/all/list%3FspecificEpithet%3Dpraevirgula%26genus%3DExogyra&prev=search
  11. http://gni.globalnames.org/name_indices/98855151/name_index_records
  12. Ivanov. M., Hrdlickova. S., and Gregorova. R., (2005), The Complete Encyclopedia of Fossils, 3rd. ed., Lisse: Rebo International, page 133
  13. Paleobiology Database, (n.d.), Exogyra (Aetostreon), [online], Exogyra (Aetostreon) entry, accessed 7 May 2013
  14. Anon, (n.d.), Aetostreon latissium As a Derived Fossil, [online], Available at: http://www.fcaq-geolotech.co.uk/shop/bivalves/96-aetostreon-latissimum-as-a-dreived-fossil.html, Accessed 7 May 2013
  15. Paleobiology Database, (n.d.), Exogyra (Aetostreon miotaurinensis, [online], Available at: http://paleodb.org/?a=basicTaxonInfo&taxon_no=118252, accessed 7 May 2013
  16. 16.0 16.1 Global Names Index, (2000), Global Names Index, [online], Available at: http://gni.globalnames.org/name_strings?page=213&search_term=ns%3AAET%2A, Accessed 7 May 2013
  17. Rubillar A.E, Lazo, E.B., (2008), Description of Aetostreon pilmatuegrossum sp. Nov. from the Lower Cretaceous of Argentina (Neuquén Basin), and significance of the conservative left valve morphology in oysters of the genus Aetostreon Bayle, [online], Available at: http://www.sciencedirect.com/science/article/pii/S0195667108001705, accessed 7 May 2013