Nummulite
Nummulites Temporal range: Tertiary | |
---|---|
Scientific classification | |
Domain: | Eukaryota
Kingdom = Protozoa |
Kingdom: | Rhizaria |
Superphylum: | Retaria |
Phylum: | Foraminifera |
Order: | Rotaliida |
Superfamily: | Nummulitacea |
Family: | Nummulitidae |
Genus: | Nummulites Lamarck, 1801 |
Species | |
Numerous |
![](../I/m/Nummulitids.jpg)
A nummulite is a large lenticular fossil, characterized by its numerous coils, subdivided by septa into chambers. They are the shells of the fossil and present-day marine protozoan Nummulites, a type of foraminiferan. Nummulites commonly vary in diameter from 1.3 cm (0.5 inches) to 5 cm (2 inches)[1] and are common in Eocene to Miocene marine rocks, particularly around southwest Asia and the Mediterranean (e.g. Eocene limestones from Egypt). Fossils up to 6 inches wide are found in the Middle Eocene rocks of Turkey.2 They are valuable as index fossils.
![](../I/m/NummuliteLyd.jpg)
The ancient Egyptians used nummulite shells as coins and the pyramids were constructed using limestone that contained nummulites.[2] It is not surprising then that the name "Nummulites" is a diminutive form of the Latin nummulus meaning "little coin", a reference to their shape.
In 1913, naturalist Randolph Kirkpatrick published a book, The Nummulosphere: an account of the Organic Origin of so-called Igneous Rocks and Abyssal Red Clays, proposing the unconventional theory that all rocks had been produced through the accumulation of forams such as Nummulites.
References
- 'Nummulite', Tiscali Dictionary of Animals , retrieved 17 August 2004
- 2. 'Biggest Microbes', Guinness World Records 2001, p. 153.
- http://paleopolis.rediris.es/cg/CG2006_M02/index.html
Further Reading
Aigner, Thomas (January 1985). "Biofabrics as Dynamic Indicators in Nummulite Accumulations". Journal of Sedimentary Research 55 (1): 131–134. doi:10.1306/212F8634-2B24-11D7-8648000102C1865D.
Kopaevich, L.F.; Lygina, E.A.; Nikishin, A.M.; Yakovishina, E.V. (2008). "The Crimean Eocene Nummulite Bank". Moscow University Geology Bulletin 63 (3): 195-8. doi:10.3103/S0145875208030083.
Racey, Andrew (2001). "A Review of Eocene Nummulite Accumulations: Structure, Formation and Reservoir Potential". Journal of Petroleum Geology 24 (1): 79–100. doi:10.1111/j.1747-5457.2001.tb00662.x.
Papazzoni, Cesare Andrea (1995). "Nummulite biostratigraphy at the Middle/Upper Eocene boundary in the northern Mediterranean area". Rivista italiana di paleontologia e stratigrafia 101 (1): 63–80.
Guido, Adriano; Papazzoni, Cesare; Mastandrea, Adelaide; Morsilli, Michele; La Russa, Mauro F.; Tosti, Fabio; Russo, Franco (June 2011). "Automicrite in a ‘nummulite bank’ from the Monte Saraceno (Southern Italy): evidence for synsedimentary cementation". Sedimentology 58 (4): 878–889. doi:10.1111/j.1365-3091.2010.01187.x.