The Amiidae are a family of basal

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 ...

es. The

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 ...

and the eyespot bowfin (''

Amia ocellicauda ''Amia ocellicauda'', the eyespot bowfin or emerald bowfin, is a species of Amia (fish), bowfin native to North America. Originally described by John Richardson (naturalist), John Richardson from Lake Huron in 1836, it was synonymized with ''Amia ...

'') are the only two species to survive today, although additional species in all four subfamilies of Amiidae are known from

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

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 ...

, and

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 ...

fossil 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 preserve ...

s. Bowfins are now found throughout eastern

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, typically in slow-moving backwaters, canals, and ox-bow lakes. When the oxygen level is low (as often happens in still waters), the bowfin can rise to the surface and gulp air into its

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ (anatomy), organ in bony fish that functions to modulate buoyancy, and thus allowing the fish to stay at desired water depth without having to maintain lift ...

, which is lined with blood vessels and can serve as a primitive

lung The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...

. Amiidae is a monophyletic group that has numerous synapomorphic characters. Amiidae were widespread and particularly rich in species during the Eocene era. During this era, they appeared to be confined almost exclusively to fresh water.

Taxonomy

The family is divided into five subfamilies, with 16 genera *Amiidae **Subfamily Amiinae (latest Cretaceous -Present) ***Genus '' Amia'' ***Genus †''

Cyclurus ''Cyclurus'' (Ancient Greek for "rounded tail") is an extinct genus of freshwater Amiidae, amiid Actinopterygii, ray-finned fish known from the Late Cretaceous to the Rupelian, Early Oligocene across much of the Northern Hemisphere. It is though ...

'' ***Genus †'' Pseudoamiatus'' **Subfamily † Amiopsinae (Late Jurassic) ***Genus †'' Amiopsis'' **Subfamily † Solnhofenamiinae (Late Jurassic) ***Genus †'' Solnhofenamia'' **Subfamily †

Vidalamiinae The Amiidae are a family of basal (phylogenetics), 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 kno ...

(Early Cretaceous) ***Genus †''

Calamopleurus ''Calamopleurus'' is a prehistoric genus of marine halecomorph ray-finned fish from the Early Cretaceous of South America and northern Africa. It was a relative of the modern bowfin, with both belonging to the family Amiidae. ''C. cylindricus'' ...

'' ***Genus †''

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 ...

'' ***Genus †''

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 ...

'' ***Genus †'' Pachyamia'' ***Genus †'' Vidalamia'' **Subfamily ''

incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

'' ***Genus †'' Nipponamia'' ***Genus †'' Hispanamia'' **Subfamily † SinamiinaeDeesri, U.; Naksri, W.; Jintasakul, P.; Noda, Y.; Yukawa, H.; Hossny, T.E.; Cavin, L. A New Sinamiin Fish (Actinopterygii) from the Early Cretaceous of Thailand: Implications on the Evolutionary History of the Amiid Lineage. Diversity 2023, 15, 491. https://doi.org/10.3390/d15040491 (Early Cretaceous) ***Genus †''

Siamamia ''Siamamia'' is an extinct genus of ray-finned fish in the family Amiidae.Deesri, U.; Naksri, W.; Jintasakul, P.; Noda, Y.; Yukawa, H.; Hossny, T.E.; Cavin, L. A New Sinamiin Fish (Actinopterygii) from the Early Cretaceous of Thailand: Implicati ...

'' ***Genus †'' Khoratamia'' ***Genus †''

Sinamia ''Sinamia'' is an extinct genus of freshwater amiiform fish which existed in China, Japan, South Korea and North Korea during the Early Cretaceous period. Like the related bowfin, it has an elongated low-running dorsal fin, though this was likel ...

'' ***Genus †'' Ikechaoamia''

References

External links

{{Taxonbar, from=Q141948 Amioidea Extant Jurassic first appearances Taxa named by Charles Lucien Bonaparte Ray-finned fish families