''Calamopleurus'' is a prehistoric genus of marine halecomorph

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

from the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

of South America and northern Africa. It was a relative of the modern

bowfin The ruddy bowfin (''Amia calva'') is a ray-finned fish native to North America. Common names include mudfish, mud pike, dogfish, grindle, grinnel, swamp trout, and choupique. It is regarded as a relict, being one of only two surviving species ...

, with both belonging to the family

Amiidae The Amiidae are a family of basal ray-finned fishes. The bowfin and the eyespot bowfin ('' Amia ocellicauda'') are the only two species to survive today, although additional species in all four subfamilies of Amiidae are known from Jurassic, Cre ...

. ''C. cylindricus'' was among the largest known amiids, rivaling the giant

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

bowfin '' Amia pattersoni'' in size. However, both were slightly smaller than ''

Melvius ''Melvius'' is a genus of vidalamiin amiid ray-finned fish from the Late Cretaceous. The type species, ''Melvius thomasi'', was described by Bryant in 1987 from Hell Creek Formation.L. J. Bryant. 1987. A new genus and species of Amiidae (Holost ...

'' and ''

Amia basiloides ''Amia basiloides'' is an extinct species of giant bowfin that inhabited western North America during the Middle or Late Paleocene, about 5-10 million years after the Cretaceous-Paleogene extinction event. The species name originates from the A ...

'', the two largest known amiids. It is one of the earliest known amiids to evolve a large body size.

Taxonomy

It is thought Calamopleurus is a

sister genus In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to ''

Maliamia ''Maliamia'' ("Malian bowfin") is an extinct genus of Amiidae, amiid ray-finned fish from the Early Eocene, known from fragmentary remains found in the Tamaguélelt Formation of Mali. It was described in 1989, based on fossils recovered by three ...

'', the last surviving member of the vidalamiines, which is the largely marine amiid group that also contained ''Calamopleurus''. Both are placed in the tribe Calamopleurini. The genus contains three species: * †''C. africanus'' Forey & Grande, 1998 - Late

Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...

/Early

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

Morocco Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...

and

Algeria Algeria, officially the People's Democratic Republic of Algeria, is a country in the Maghreb region of North Africa. It is bordered to Algeria–Tunisia border, the northeast by Tunisia; to Algeria–Libya border, the east by Libya; to Alger ...

* †''C. cylindricus''

Agassiz Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history. Spending his early life in Switzerland, he recei ...

, 1841 - Late

Aptian The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...

/Early Albian of

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

( Crato and

Santana Santana may refer to: Transportation * Volkswagen Santana, an automobile * Santana Cycles, manufacturer of tandem bicycles * Santana Motors, a former Spanish automobile manufacturer * Sailboat designs by W. D. Schock Corp ** Santana 20 ** Santan ...

Formations) * †''C. mawsoni'' Woodward, 1902 ''-'' Late

Hauterivian The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous Epoch or a stage in the Lower Cretaceous Series. It spans the time between 132.6 ± 2 Ma and 125.77 (million years ago). The Hauterivian is preceded by the Valangi ...

/Early

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 125.77 Ma (million years ago) and 121.4 ± 1.0 Ma (Historically, this stage was placed at 129.4 million to approximately 125 million years ago) It is a ...

of Brazil (

Bahia Group The Bahia Group, also known as Bahia Series, is an Early Cretaceous geologic group of the Recôncavo Basin in Bahia, Brazil dating back to the Valanginian and Hauterivian. Dinosaur remains are among the fossils that have been recovered from unit, ...

)

''Calamopleurus africanus''

This species lived in southern Morocco and Algeria during the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

period in the late Albian and early Cenomanian. It was described from fragmentary remains in the

Kem Kem beds The Kem Kem Group (commonly known as the Kem Kem beds) is a geological group in the Kem Kem region of eastern Morocco, whose strata date back to the Cenomanian stage of the Late Cretaceous. Its strata are subdivided into two geological formations ...

. Ossified dermopterotic ribs were inferred from a loose association between the dermosphenotic and the roof of the skull.

References

† A dagger, obelisk, or obelus is a typographical mark that usually indicates a footnote if an asterisk has already been used. The symbol is also used to indicate death (of people) or extinction (of species or languages). It is one of the mo ...

Prehistoric ray-finned fish genera Cretaceous fish of Africa Early Cretaceous fish of South America Crato Formation Romualdo Formation Fossils of Morocco Fossils of Algeria Taxa named by Louis Agassiz Hauterivian genus first appearances Barremian genera Aptian genera Albian genera Cenomanian genus extinctions Fossil taxa described in 1841 {{Amiiformes-stub