''Cladocyclus'' (derived from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

κλάδος/kládos ("branch") and κύκλος/kýklos ("circle")) is an extinct genus of marine ichthyodectiform

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 middle

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 ...

. It was a predator of about in length.

Taxonomy

It contains the following species: * †''C. gardneri''

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 -

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 ...

of northeastern Brazil ( Romualdo and

Crato Formation The Crato Formation is a geologic formation (stratigraphy), formation of Early Cretaceous (Aptian) age in northeastern Brazil's Araripe Basin. It is an important Lagerstätten, Lagerstätte (undisturbed fossil accumulation) for palaeontology, pa ...

s of the

Araripe Basin The Araripe Basin () is a rift basin covering about ,Neto et al., 2013, p.1 in Ceará, Piauí and Pernambuco states of northeastern Brazil. It is bounded by the Patos and Pernambuco lineaments, and is situated east of the Parnaíba Basin, south ...

) (=''C. ferus'' Santos, 1950) * †''C. geddesi'' Berell, 2014 - late Albian of

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

, Australia (

Winton Formation The Winton Formation is a Cretaceous Formation (geology), geological formation in central-western Queensland, Australia. It is late Albian to early Turonian in age. The formation blankets large areas of central-western Queensland. It consists of ...

) An indeterminate specimen, previously assigned to ''

Chirocentrites ''Chirocentrites'' is an extinct genus of marine ray-finned fish in the order Ichthyodectiformes. It contains a single species, ''C. coroninii'', from the Late Cretaceous (Cenomanian) of Slovenia (locality also sometimes given as Gorizia, Italy). ...

'', is known from the Albian-aged

Pietraroja Plattenkalk The Pietraroia Plattenkalk is a Cretaceous geologic Formation (geology), formation located in the Italy, Italian municipality of Pietraroja,

of Italy. Indeterminate specimens, represented by complete remains, are also known from the

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 ...

of Morocco, which are not to be confused with ''C. pankowskii'', which was discovered 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 ...

in 2007, but has since been reclassified to the genus ''

Aidachar ''Aidachar'' (named for Aydahar, a mythical Kazakh dragon) is an extinct genus of marine ichthyodectiform ray-finned fish from the Late Cretaceous (Cenomanian-Turonian) of Central Asia and North Africa. The type species is ''A. paludalis'', ...

''. The species ''C. lewesiensis'' Agassiz, 1887 from the

of England and ''C. strehlensis'' Geinitz, 1868 from the

Turonian The Turonian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the second age (geology), age in the Late Cretaceous epoch (geology), Epoch, or a stage (stratigraphy), stage in the Upper Cretaceous series (stratigraphy), ...

of Germany, which were described based only on fossil scales, are considered '' nomen dubia'' and likely do not belong to this genus. The dubious species ''C. occidentalis'' Leidy, 1857 from the

Coniacian The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded by ...

-to-

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

-aged

Niobrara Formation The Niobrara Formation , also called the Niobrara Chalk, is a geologic formation in North America that was deposited between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian stages of the Late Cretaceous. It is com ...

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state, state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota people, Dakota Sioux ...

, US is based on scales that likely belong to ''

Ichthyodectes ''Ichthyodectes'' is an extinct genus of ichthyodectid ray-finned fish which lived during the Late Cretaceous. Fossils of the species included have been found from Canada to Texas. Description ''Ichthyodectes ctenodon'' ("fish biter with comb ...

ctenodon''.

Ecology

Although ''C. gardneri'' and other cladocyclids are generally thought of as

marine fish Saltwater fish, also called marine fish or sea fish, are fish that live in seawater. Saltwater fish can swim and live alone or in a large group called a school. Saltwater fish are very commonly kept in aquariums for entertainment. Many saltwater ...

, the Australian species ''C. geddesi'' was recovered from a freshwater formation, despite showing clear adaptations to the open ocean. This specimen may have been of an individual that swam upstream from the ocean.

Gallery

File:Cladocyclus gardneri 2.jpg, ''Cladocyclus gardneri'' File:Cladocyclus Vienna.jpg, Fossil in Vienna

References

Ichthyodectiformes Prehistoric ray-finned fish genera Cretaceous bony fish Early Cretaceous fish of South America Cretaceous fish of Europe Cretaceous fish of Australia Late Cretaceous fish of Africa Albian genus first appearances Cenomanian genus extinctions Cretaceous Morocco Fossils of Morocco Cretaceous Italy Fossils of Italy Crato Formation Romualdo Formation Fossil taxa described in 1841 Taxa named by Louis Agassiz {{Ichthyodectiformes-stub