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 preserved ...

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

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

n ''Nummulites'', a type of

foraminifera Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular Ectoplasm (cell biology), ectoplasm for catching food and ot ...

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

Miocene The Miocene ( ) is the first 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 means "less recen ...

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 north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...

(e.g. Eocene limestones from

Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Mediter ...

). 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 Stratum, strata by using the fossil assemblages contained within them.Hine, Robert. “Biostratigraphy.” ''Oxford Reference: Dictiona ...

s. The ancient Egyptians used nummulite shells as coins and the pyramids were constructed using limestone that contained nummulites. 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 branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

'' nummulus'' meaning "little coin", a reference to their shape. In 1913, naturalist

Randolph Kirkpatrick Randolph Kirkpatrick (1863 – 1950) was a British spongiologist, cnidariologist and bryozoologist. He was assistant keeper of lower invertebrates at the British Natural History Museum from 1886 until his retirement in 1927. 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 The Urbasa Range (''Urbasa mendilerroa'' in Basque and ''Sierra de Urbasa'' in Spanish) is a mountain range of western Navarre, Spain, part of the Basque Mountains. Its highest point is the 1,183-metre-high Baiza. Urbasa is a karstic Karst ...

Navarre Navarre (; es, Navarra ; eu, Nafarroa ), officially the Chartered Community of Navarre ( es, Comunidad Foral de Navarra, links=no ; eu, Nafarroako Foru Komunitatea, links=no ), is a foral autonomous community and province in northern Spain, ...

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

References

*http://paleopolis.rediris.es/cg/06/M02/index.html

Gallery

References

Further reading