''Rafinesquina'' is an

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of large

brachiopod Brachiopods (), phylum (biology), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear e ...

that existed from the

Darriwilian The Darriwilian is the upper stage of the Middle Ordovician. It is preceded by the Dapingian and succeeded by the Upper Ordovician Sandbian Stage. The lower boundary of the Darriwilian is defined as the first appearance of the graptolite species ' ...

to the

Ludlow epoch In the geological timescale, the Ludlow Epoch (from 427.4 ± 0.5 million years ago to 423.0 ± 2.3 million years ago) occurred during the Silurian Period, after the end of the Homerian Age. It is named for the town of Ludlow in Shropshire, Engl ...

. The genus was named in honor of

polymath A polymath or polyhistor is an individual whose knowledge spans many different subjects, known to draw on complex bodies of knowledge to solve specific problems. Polymaths often prefer a specific context in which to explain their knowledge, ...

Constantine Samuel Rafinesque-Schmaltz Constantine Samuel Rafinesque-Schmaltz (; 22 October 178318 September 1840) was a French early 19th-century polymath born near Constantinople in the Ottoman Empire and self-educated in France. He traveled as a young man in the United States, ult ...

Description

''Rafinesquina's'' members were

epifaunal Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and ''funga'', respectively. Flora, fauna, funga and other forms of life are collectively r ...

, meaning they lived on top of the seafloor, not buried within it, and were suspension feeders. ''Rafinesquina'' normally have a concavo-convex profile, with radiating striae of alternating size which are crossed with finer concentric striae. Their width is usually greater than their length, like most Strophomenids. Members of this genus had shells that grew in increments, with each increment forming a layer of the shell (much like

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

s do with their rings). In 1982, Gary D. Rosenberg analyzed specimens of '' Rafinesquina alternata'' previously inferred to have lived in a shallow

subtidal The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminate ...

environment and proposed it could be possible to estimate the total number of days in a

lunar month In lunar calendars, a lunar month is the time between two successive syzygies of the same type: new moons or full moons. The precise definition varies, especially for the beginning of the month. Variations In Shona, Middle Eastern, and Euro ...

(the period between full moons) during the

Late Ordovician The Late Ordovician is the third and final epoch of the Ordovician period, lasting million years and spanning from around 458.2 to 443.1 million years ago. The rocks associated with this epoch are referred to as the Upper Ordovician Series. At ...

using layer counting.

Distribution

''Rafinesquina'' specimens had a cosmopolitan distribution, and their fossils can be found in

the Americas The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.'' Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sin ...

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

, and

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

Species

Species in the genus ''Rafinesquina'' include:Catalog of Life
/ref> *'' R. alternata'' (Conrad, 1838) *'' R. declivis'' (James, 1874) *'' R. delicata'' Williams, 1974 *'' R. deltoidea'' (Conrad, 1838) *'' R. insidiosa'' Williams, 1962 *'' R. jeffersonensis'' Bradley, 1930 *'' R. latisculptilus'' (Savage, 1913) *'' R. lignani'' Vilas, 1985 *'' R. mesicosta'' Shumard, 1860 *'' R. mucronata'' Foerste, 1914 *'' R. nasuta'' (Emmons, 1842) *'' R. oanduensis'' Oraspold, 1956 *'' R. orvikui'' Oraspold, 1956 *'' R. percensis'' Cooper and Kindle, 1936 *'' R. planulata'' Cooper, 1956 *'' R. ponderosa'' Hayes and Ulrich, 1903 *'' R. pseudoloricata'' (Barrande, 1848) *'' R. relicula'' Benedetto, 1995 *'' R. stropheodontoides'' (Savage, 1913) *'' R. trentonensis'' (Hall, 1847) *'' R. ultrix'' Marek and Havlíček, 1967 *'' R. urbicola'' Marek and Havlíček, 1967

References

Prehistoric brachiopod genera Ordovician brachiopods Silurian brachiopods Paleozoic animals of Asia Paleozoic animals of Europe Paleozoic animals of North America Paleozoic animals of South America Paleozoic brachiopods of Asia Paleozoic brachiopods of Europe Paleozoic brachiopods of North America Paleozoic brachiopods of South America Fossils of Argentina Fossils of Belarus Fossils of Bolivia Fossils of Canada Paleozoic life of British Columbia Paleozoic life of Manitoba Paleozoic life of Newfoundland and Labrador Paleozoic life of the Northwest Territories Paleozoic life of Nunavut Paleozoic life of Ontario Verulam Formation Paleozoic life of Quebec Fossils of China Fossils of the Czech Republic Letná Formation Fossils of Estonia Fossils of France Fossils of Latvia Fossils of Lithuania Fossils of North Korea Fossils of Norway Fossils of Portugal Fossils of Russia Fossils of South Korea Fossils of Spain Fossils of Great Britain Fossils of the United States Fossils of Georgia (U.S. state) Fossils of Venezuela Fossil taxa described in 1892 {{brachiopod-stub