Osteoglossiformes is a relatively primitive order of ray-finned fish that contains two sub-orders, the Osteoglossoidei and the Notopteroidei. All of at least 245 living species inhabit freshwater. They are found in South America, Africa, Australia and southern Asia, having first evolved in Gondwana before that continent broke up. In 2008, several new species of marine osteoglossiforms were described from the Danish Eocene Fur Formation, dramatically increasing the diversity of this group. This implies that the Osteoglossomorpha is not a primary freshwater fish group with the osteoglossiforms having a typical Gondwana distribution.
Arowanas are freshwater bony fish of the subfamily Osteoglossinae, also known as bony tongues. In this family of fish, the head is bony and the elongated body is covered by large, heavy scales, with a mosaic pattern of canals. The dorsal and anal fins have soft rays and are long based, while the pectoral and ventral fins are small. The name "bonytongues" is derived from a toothed bone on the floor of the mouth, the "tongue", equipped with teeth that bite against teeth on the roof of the mouth. The arowana is a facultative air breather and can obtain oxygen from air by sucking it into its swim bladder, which is lined with capillaries like lung tissue.
The Asian arowana comprises several phenotypic varieties of freshwater fish distributed geographically across Southeast Asia. While most consider the different varieties to belong to a single species, work by Pouyaud et al. (2003) differentiates these varieties into multiple species. They have several other common names, including Asian bonytongue, dragonfish, and a number of names specific to the different color varieties.
Scleropages jardinii, the Gulf saratoga, Australian bonytongue, pearl arowana or northern saratoga, is a freshwater bony fish native to Australia and New Guinea, one of two species of fishes sometimes known as Australian arowana, the other being Scleropages leichardti. It has numerous other common names, including northern saratoga, toga and barramundi. It is a member of the subfamily Osteoglossinae, a (basal) teleost group. Its scientific name is sometimes spelled S. jardini.
Osteoglossidae is a family of large-sized freshwater fish, which includes the arowanas. They are commonly known as bonytongues. The family has been regarded as containing two extant subfamilies Arapaiminae and Osteoglossinae, with a total of five living genera, but these are regarded as valid families in Eschmeyer's Catalog of Fishes The extinct Phareodontinae are known from worldwide during the Late Cretaceous and Paleogene; they are generally considered to be crown group osteoglossids that are more closely related to one of the extant osteoglossid subfamilies than the other, though their exact position varies.
The African arowana or Nile arowana is a species of bonytongue. Despite being called an "arowana", the African arowana is more closely related to arapaimas, the only other members in the subfamily Arapaiminae, than the South American, Asian, and Australian arowanas in the subfamily Osteoglossinae. Compared to these, the African arowana has a more terminal mouth and is the only one that feeds extensively on plankton.
Clarias is a genus of catfishes of the family Clariidae, the airbreathing catfishes. The name is derived from the Greek chlaros, which means lively, in reference to the ability of the fish to live for a long time out of water.
Pangasius is a genus of medium-large to very large shark catfishes native to fresh water in South and Southeast Asia. The term "pangasius" is sometimes used to specifically refer to the commercially important basa fish, P. bocourti.
Eoalligator is an extinct genus of alligatoroid crocodilian from Paleocene deposits in China.
Tillodontia is an extinct suborder of eutherian mammals known from the Early Paleocene to Late Eocene of China, the Late Paleocene to Middle Eocene of North America where they display their maximum species diversity, the Middle Eocene of Pakistan, and the Early Eocene of Europe. Leaving no descendants, they are most closely related to the pantodonts, another extinct group. The tillodonts were medium- to large-sized animals that probably fed on roots and tubers in temperate to subtropical habitats.
Opsithrissops is an extinct genus of prehistoric bony fish that lived during the Thanetian stage of the Paleocene epoch. It is a 120 centimetres (3.9 ft) fish in the family Osteoglossiformes which includes other bony-tongues such as the extant species of arowana and arapaima.
Brychaetus is an extinct genus of prehistoric marine bonytongue fish known from the Late Cretaceous to the late Eocene of Europe, North America, and northern Africa.
Amyzon is an extinct genus belonging to the sucker family Catostomidae first described in 1872 by E. D. Cope. There are six valid species in the genus. Amyzon are found in North American fossil sites dated from the Early Eocene in Montana and Washington USA, as well as the British Columbian sites at McAbee Fossil Beds, Driftwood Canyon, and the "Horsefly shale", as well as Early Oligocene sites in Nevada USA. One Middle Eocene species is known from the Xiawanpu Formation of China. The Ypresian species A. brevipinne of the Allenby Formation was redescribed in 2021 and moved to a separate monotypic genus Wilsonium.
Phareodus is a genus of freshwater fish from the Paleocene to the Eocene of Australia, Europe and North and South America.
Joffrichthys is a genus of prehistoric bony fish. This North American genus includes three species, J. symmetropterus, J. tanyourus and J. triangulpterus. The last species is known from the Paleocene of the Sentinel Butte Formation of North Dakota.
Loaches are fish of the superfamily Cobitoidea. They are freshwater, benthic (bottom-dwelling) fish found in rivers and creeks throughout Eurasia and northern Africa. Loaches are among the most diverse groups of fish; the 1249 known species of Cobitoidea comprise about 107 genera divided among 9 families.
Coryphodontidae is an extinct family of pantodont mammals known from the Late Paleocene to the Middle Eocene of Eurasia and North America.
Arapaimidae is a family of freshwater ray-finned fish belonging to the family Osteoglossidae. It includes the South American arapaimas of the Amazon and Essequibo basins and the African arowana from the watersheds of the Sahelo-Sudanese region, Senegal, Gambia, and parts of Eastern Africa. This family is sometimes treated as the subfamily Arapaiminae. A commonly used synonym is Heterotidinae, but according to the ICZN, Arapaimidae has priority.
This list of fossil fishes described in 2019 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes, and other fishes of every kind that were described during the year 2019, as well as other significant discoveries and events related to paleoichthyology that occurred in 2019.
