''Cyclopoma'' (from , 'circular' and 'cover') is an extinct genus of marine

percomorph Percomorpha () is an extremely large and diverse clade of ray-finned fish. With more than 17,000 known species (including Scombroidei, tuna, Syngnathiformes, seahorses, gobies, Cichlidae, cichlids, flatfish, Labridae, wrasse, Perciformes, perches ...

fish from the

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

. It is known from the

Ypresian In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

to the

Lutetian The Lutetian is, in the geologic timescale, a stage (stratigraphy), stage or age (geology), age in the Eocene. It spans the time between . The Lutetian is preceded by the Ypresian and is followed by the Bartonian. Together with the Bartonian it ...

of Europe and eastern North America. It is alternatively classified in either the Percichthyidae (which otherwise contains only species from South America and Australia) or in the

Centropomidae ''Centropomus'' is a genus of predominantly marine fish comprising the family Centropomidae. The type species is '' Centropomus undecimalis'', the common snook. Commonly known as snooks or ''róbalos'', the ''Centropomus'' species are native to ...

(represented by modern snooks). The following species are known: * †''C. folmeri'' Weems, 1999 - Ypresian of

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

, USA (

Nanjemoy Formation The Nanjemoy Formation is a Formation (geology), geologic formation pertaining to both the Wilcox Group and the Pamunkey Group of the eastern United States, stretching across the states of Virginia, Maryland, and the District of Columbia. The f ...

) * †''C. gigas''

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 ...

, 1833 - Ypresian of

Monte Bolca Monte Bolca is an Ypresian, Early Eocene-aged geologic site located near Verona, Italy, Verona, Italy. A ''Konservat-Lagerstätte'', it contains an extremely well-preserved and diverse marine biota, including the most diverse fish fauna of any Ce ...

, Italy (='' Amia indica'' Volta, 1796, ''

Smerdis Bardiya or Smerdis ( ; ; possibly died 522 BCE), also named as Tanyoxarces (; ) by Ctesias, was a son of Cyrus the Great and the younger brother of Cambyses II, both Persian kings. There are sharply divided views on his life. Bardiya eithe ...

micracanthus'' Agassiz, 1833) * †''C. spinosum'' Agassiz, 1833 - Ypresian of Monte Bolca, Italy (not recognized in more recent reviews) An indeterminate species is known from the

-aged

Lutetian limestone Lutetian limestone (in French language, French, ''calcaire lutécien'', and formerly ''calcaire grossier'') — also known as “Paris stone” — is a variety of limestone particular to the Eocene-aged deposits in the Paris Basin of France, mos ...

of France. As its name suggests, ''C. gigas'' was a large fish that could reach up to in length. It likely inhabited brackish waters close to river mouths. Cyclopoma

It has been alleged that Louis Agassiz struggled with excavating the type specimen of ''C. spinosum'', despite continuously studying it. For two nights, he dreamed of the specimen appearing fully restored, and on the third night, sketched his vision of the restored specimen while half-awake. When he continued preparing the fossil specimen the following day, the fully excavated specimen was allegedly found to be exactly as he had dreamed and sketched.

References

Percomorpha Prehistoric percomorph genera Eocene fish of Europe Eocene fish of North America Ypresian genus first appearances Lutetian genus extinctions Fossils of Italy Fossils of France Fossils of the United States Taxa named by Louis Agassiz Fossil taxa described in 1833 {{paleo-rayfinned-fish-stub

See also

References