''Concavus'' is a genus of

barnacle Barnacles are arthropods of the subclass (taxonomy), subclass Cirripedia in the subphylum Crustacean, Crustacea. They are related to crabs and lobsters, with similar Nauplius (larva), nauplius larvae. Barnacles are exclusively marine invertebra ...

Species

WoRMS The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

recognizes the following two species: * '' Concavus concavus'' (Bronn, 1831) —

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58early Pleistocene The Early Pleistocene is an unofficial epoch (geology), sub-epoch in the international geologic timescale in chronostratigraphy, representing the earliest division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently esti ...

; Western Europe. * '' Concavus crassostricola'' Zullo, 1984 —

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ...

; North Carolina and northern Florida.

Taxonomic history

The genus was

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

by William A. Newman in 1982. His original list of subgenera and species for the genus was the following: * ''Concavus'' genus ** ''Concavus'' subgenus *** '' C. concavus'' ** ''Menesiniella'' subgenus *** ''C. (M.) aquila'' *** ''C. (M.) regalis'' ** ''Arossia'' subgenus *** ''C. (A.) panamensis'' **** ''C. (A.) p. panamensis'' **** ''C. (A.) p. eyerdami'' *** ''C. (A.) henryae'' Newman noted there were multiple fossil taxa in this genus, but didn't classify any except for the type species ''C. concavus''. In 1992, Victor A. Zullo revised the genus. He created a new subfamily, Concavinae, with '' Tamiosoma'' (the senior synonym of ''

Menesiniella ''Menesiniella'' is a genus of the barnacle family Balanidae The Balanidae is a family of barnacle Barnacles are arthropods of the subclass (taxonomy), subclass Cirripedia in the subphylum Crustacean, Crustacea. They are related to crabs ...

'' according to Zullo), '' Arossia'' and ''Concavus'' among its genera. With his revision, ''Concavus'' only consists of the two species ''C. concavus'' and ''C. crassostricola''.

Fossil records

This genus is known in the

fossil record 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 ...

s from the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

to the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

(age range: from 28.4 to 0.012 million years ago). Fossils are found in the marine strata of United States, Italy, Mexico, Morocco, Algeria, France, Haiti, Madagascar, Panama, Colombia and Slovenia.Fossilworks
/ref>

Notes

References

Barnacles Aquitanian genus first appearances {{Maxillopoda-stub