| Nummulite | |
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| Fossil nummulitid foraminiferans showing microspheric and megalospheric individuals; Eocene of the United Arab Emirates; scale in mm. | |
Scientific classification | |
| Domain: | Eukaryota |
| Clade: | Diaphoretickes |
| Clade: | SAR |
| Clade: | Rhizaria |
| Phylum: | Retaria |
| Subphylum: | Foraminifera |
| Class: | Globothalamea |
| Order: | Rotaliida |
| Family: | Nummulitidae |
| Genus: | Nummulites Lamarck, 1801 |
| Species | |
Numerous | |
Anummulite is a largelenticularfossil, characterised by its numerous coils,[1] subdivided by septa into chambers. They are the shells of the fossil and present-day marineprotozoanNummulites, a type offoraminiferan. Nummulites commonly vary in diameter from 1.3 cm (0.5 inches) to 5 cm (2 inches)[2] and are common inEocene toMiocene marine rocks, particularly around southwest Asia and theMediterranean in the area that once constituted theTethys Ocean, such as Eocene limestones fromEgypt[3] or fromPakistan.[4] Fossils up to six inches wide are found in the Middle Eocene rocks of Turkey.[5] They are valuable asindex fossils.
Theancient Egyptians used nummulite shells as coins and thepyramids were constructed using limestone that contained nummulites.[3][6] It is not surprising then that the nameNummulites is a diminutive form of theLatinnummulus 'little coin', a reference to their shape.[7]
In 1913, naturalistRandolph 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 asNummulites.
Because nummulites are very abundant, easy to recognize, and lived in certainbiozones, they are used asguide fossils.It is worth highlighting that thanks to the appearance of Nummulites tavertetensis in the Shallow Bentic Zone 15 (SBZ 15), it was possible to date the oldest fossil remains ofSirenio inWestern Europe found in a new paleontological site, in Santa Brígida,Amer (La Selva,Catalunya,Spain) near an oldquarry ofstone limestone with nummulites.[8]
Authority control databases: National |
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