The beardfishes consist of a single extant genus, Polymixia, of deep-sea marine ray-finned fish named for their pair of long hyoid barbels. They are classified in their own order Polymixiiformes. But as Nelson says, "few groups have been shifted back and forth as frequently as this one, and they were recently added to Paracanthoptergii". For instance, they have previously been classified as belonging to the Beryciformes, and are presently considered either paracanthopterygians or the sister group to acanthopterygians. They are of little economic importance.
Xiphactinus is an extinct genus of large predatory marine ray-finned fish that lived during the late Albian to the late Maastrichtian. The genus grew up to 5–6 metres (16–20 ft) in length, and superficially resembled a gargantuan, fanged tarpon. It is a member of the extinct order Ichthyodectiformes, which represent close relatives of modern teleosts.
Cooyoo is an extinct genus of ichthyodectid ray-finned fish known from the Lower Cretaceous. It contains a single species, C. australis, known from the Albian-aged Toolebuc and Allaru Formations of Queensland, Australia. C. australis was originally named by Arthur Smith Woodward as a species of Portheus in 1894, which was later amended to Xiphactinus.
Ichthyodectiformes is an extinct order of marine stem-teleost ray-finned fish. The order is named after the genus Ichthyodectes, established by Edward Drinker Cope in 1870. Ichthyodectiforms are usually considered to be some of the closest relatives of the teleost crown group.
Belonostomus is a genus of prehistoric ray-finned fish that was described by Louis Agassiz in 1844. It is a member of the order Aspidorhynchiformes, a group of fish known for their distinctive elongated rostrums.
Pachythrissops is an extinct genus of ray-finned fish. It contains two species, P. laevis from the Purbeckian of England and P. propterus from the Tithonian of Germany. A third species, P. vectensis, has been reassigned to the elopiform genus Arratiaelops. Pachythrissops is often regarded as one of the most primitive members of the order Ichthyodectiformes; however, a phylogenetic analysis by Cavin et al. (2013) placed it and the related genus Ascalabothrissops outside the group.
Apateodus is a genus of prehistoric marine ray-finned fish which was described by Woodward in 1901. It was a relative of modern lizardfish and lancetfish in the order Aulopiformes, and one of a number of prominent nektonic aulopiforms of Cretaceous marine ecosystems.
Prionolepis is a genus of prehistoric ray-finned fish belonging to the order Alepisauriformes.
Bananogmius is an extinct genus of marine ray-finned fish that was found in what is now North America and Europe during the Late Cretaceous, from the Cenomanian to the Santonian. It lived in the Western Interior Seaway, which split North America in two during the Late Cretaceous, as well as the proto-North Sea of Europe.
Cladocyclus is an extinct genus of marine ichthyodectiform ray-finned fish from the middle Cretaceous. It was a predator of about 1.20 metres (3.9 ft) in length.
Ctenothrissa is a prehistoric genus of marine ray-finned fish in the order Ctenothrissiformes. It contains a number of species known from the Late Cretaceous of England and Lebanon.
Crossognathus is an extinct genus of marine ray-finned fish from the Early Cretaceous of Europe. It is the type genus of the order Crossognathiformes and the family Crossognathidae.
Coelodus is an extinct genus of marine and possibly freshwater pycnodont fish. It contains only one definitive species, C. saturnusHeckel, 1854, from the Late Cretaceous of Slovenia. Other species from the Late Jurassic to the Eocene have also been attributed to this genus based on isolated dental elements, but their assignment to Coelodus is uncertain, and this genus likely represents a non-monophyletic wastebasket taxon. A potential diagnostic trait is a prearticular tooth row with three regular highly elongated teeth.
Clupavus is an extinct genus of marine ray-finned fish that lived during the middle of the Cretaceous period. It is known from North Africa, Europe, Brazil, and possibly North America.
Caeus is an extinct genus of prehistoric marine ray-finned fish, closely related to the modern milkfish. It contains a single species, C. leopoldi from the Early Cretaceous of the Pietraroja Plattenkalk, Italy. It is one of the largest teleosts known from the Pietraroja formation, and is known by only a single specimen.
Dapalis is an extinct genus of prehistoric glassfish known from the Late Cretaceous to the Early Miocene. It is known from both freshwater and marine habitats of India, Australia, New Zealand, and much of mainland Europe.
Pycnodontidae is an extinct family of ray-finned fishes, ranging from the Jurassic period until the Eocene. It was the largest and most derived family of the successful Mesozoic fish order Pycnodontiformes, and one of only two families to survive into the Cenozoic.
Armigatus is an extinct genus of marine clupeomorph fishes belonging to the order Ellimmichthyiformes. These fishes lived in the Cretaceous ; their fossil remains have been found in Mexico, Europe, the Middle East and North Africa, suggesting the genus ranged across the Tethys Sea.
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.
The Akrabou Formation is a Late Cretaceous -aged geological formation and Konservat-Lagerstätte in Morocco. It overlies the slightly older freshwater deposits of the Kem Kem Group, which it was once thought to be apart of. It was deposited over following the Kem Kem ecosystem's submergence by the Tethys Ocean during a marine transgression from the Cenomanian-Turonian boundary event, as part of a wider deposition of carbonate platforms across the region from the event.
