A nummulite is a large lenticular

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

, characterised by its numerous coils, subdivided by septa into chambers. They are the shells of the fossil and present-day marine

protozoa Protozoa (: protozoan or protozoon; alternative plural: protozoans) are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically ...

n ''Nummulites'', a type of

foraminifera Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell bio ...

n. Nummulites commonly vary in diameter from 1.3 cm (0.5 inches) to 5 cm (2 inches) and are common in

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

marine rocks, particularly around southwest Asia and the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

in the area that once constituted the

Tethys Ocean The Tethys Ocean ( ; ), also called the Tethys Sea or the Neo-Tethys, was a prehistoric ocean during much of the Mesozoic Era and early-mid Cenozoic Era. It was the predecessor to the modern Indian Ocean, the Mediterranean Sea, and the Eurasia ...

, such as Eocene limestones from

Egypt Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...

or from

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

. Fossils up to six inches wide are found in the Middle Eocene rocks of Turkey. They are valuable as

index fossil Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. "Biostratigraphy." ''Oxford Reference: Dictionary of Biology ...

s. The

ancient Egypt Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower E ...

ians used nummulite shells as coins and the

pyramids A pyramid () is a Nonbuilding structure, structure whose visible surfaces are triangular in broad outline and converge toward the top, making the appearance roughly a Pyramid (geometry), pyramid in the geometric sense. The base of a pyramid ca ...

were constructed using limestone that contained nummulites.Kaplan, Sarah,
Brilliance without a brain
'', Speaking of Science, The Washington Post, March 7, 2018 It is not surprising then that the name ''Nummulites'' is a diminutive form of the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

'' nummulus'' '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''.

Gallery

Image:Makroforaminiferoak.jpg, Fossil nummulites in Urbasa,

Navarre Navarre ( ; ; ), officially the Chartered Community of Navarre, is a landlocked foral autonomous community and province in northern Spain, bordering the Basque Autonomous Community, La Rioja, and Aragon in Spain and New Aquitaine in France. ...

Image:NummuliteLyd.jpg, 'A Nummilite, viewed from above, and horizontally bisected'

Use

Because nummulites are very abundant, easy to recognize, and lived in certain biozones, they are used as guide 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 of Sirenio in

Western Europe Western Europe is the western region of Europe. The region's extent varies depending on context. The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the Western half of the ancient Mediterranean ...

found in a new paleontological site, in Santa Brígida, Amer ( La Selva, Catalunya,

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

) near an old

quarry A quarry is a type of open-pit mining, open-pit mine in which dimension stone, rock (geology), rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some juri ...

of stone limestone with nummulites.Fuentes-Buxó, R., or, A. 2016. Troballa de restes de sireni al Lutecià (Eocè mitjà) de Santa Brígida (Amer, La Selva, Girona). Treballs del Museu de Geologia de Barcelona, 22: 19-24 .
/ref>

Gallery

Use

References

Further reading