Pycnodus is an extinct genus of ray-finned fish from the Eocene period. It is wastebasket taxon, although many fossils from Jurassic or Cretaceous are assigned to this genus, only Eocene species, P. apodus is valid. As its name suggests, it is the type genus of Pycnodontiformes.
Gasteroclupea is a genus of prehistoric ellimmichthyiform fish that is distantly related to modern anchovies and herrings. It contains one species, G. branisai. It inhabited freshwater or estuarine habitats across South America during the Campanian and Maastrichtian stages of the Late Cretaceous period, and it briefly survived beyond the K-Pg boundary into the Danian stage of the Paleocene, making it among the few genera from its order to survive into the Cenozoic. Fossils of the genus have been found in the Yacoraite Formation of Argentina, the Chaunaca Formation, Santa Lucía Formation, and El Molino Formation of Bolivia, and the Navay Formation in Venezuela.
Euzaphlegidae is a family of extinct escolar-like fish closely related to the snake mackerels. Fossils of euzaphlegids are found from Paleocene to Late Miocene-aged marine strata of Europe, the Caucasus Mountains, India, Iran, Turkmenistan, Italy, and Southern California.
Beerichthys is an extinct genus of prehistoric marine ray-finned fish. It contains a single species, B. ingens, that was a member of the Ypresian London Clay fauna of lower Eocene England.
Acestrus is an extinct genus of prehistoric marine ray-finned fish that lived during the lower Eocene in Europe. It contains one species, A. ornatus from the London Clay, known from a single braincase. It is thought to possibly be closely allied with billfish based on the braincase morphology, although it remains uncertain whether it had the rostrum characteristic of billfishes. Some authorities have suggested blochiid affinities.
Kushlukia is an extinct genus of prehistoric bony fish, closely related to the luvar, that lived during the lower Eocene. K. permira is from Eocene portion of the Danata Formation Lagerstatten, of Turkmenistan. A second, as yet undescribed species is from the Fuller's Earth formation Lagerstatten in the Barmer District, of Ypresian Rajasthan, India.
Argilloberyx is an extinct genus of prehistoric marine bony fish that lived during the lower Eocene. It contains one species, A. prestwichae, known from the London Clay Formation on the Isle of Sheppey, United Kingdom. It is considered a member of the family Berycidae.
Aphanepygus is an extinct genus of prehistoric marine holostean ray-finned fish that lived during the lower Cenomanian. It inhabited the former Tethys Ocean, with remains known from Lebanon and Croatia. Its exact affinities are uncertain, although it is usually recovered as a relative of the macrosemiids. However, other authorities recover it in the Ionoscopiformes.
Berycopsia is an extinct genus of beardfish that lived during the Turonian stage of the Late Cretaceous. It contains a single species, B. inopinnata, that inhabited marine habitats of the Tethys Sea around what is now Croatia.
Balistomorphus is an extinct genus of prehistoric triggerfish during the early Oligocene epoch in what is now Canton Glarus, Switzerland. It inhabited the marine environment of the Tethys Ocean.
Archaephippus is an extinct genus of prehistoric spadefish that lived from the early Eocene. It contains a single species, A. asper, known from Italy. Several exquisitely preserved fossils have been found from the Monte Bolca lagerstatten. Some juvenile specimens preserve the vertical striped coloration that they would have likely had in life.
Amphiperca is an extinct genus of prehistoric freshwater perciform fish that lived from the early to middle Eocene of Europe. It has one known species, A. multiformis, known from the famous Messel Pit of Germany. Indeterminate remains are known from concurrent formations in Occitanie, France. It was a predatory fish that is known to have fed on Thaumaturus and Rhenanoperca.
Aglyptorhynchus is an extinct genus of prehistoric marine billfish that was distributed worldwide from the early Eocene to the early Miocene. Fossils are primarily known from the Northern Hemisphere, but one species is also known to have inhabited the waters off New Zealand.
Aluvarus praeimperialis is an extinct ray-finned fish, known from two headless fossil specimens found in the Pabdeh Formation, a Late Eocene stratum from the Priabonian epoch, of what is now Iran. A. praeimperialis was originally thought to be a luvar, described as "Luvarus praeimperialis", as it was thought to be a predecessor to the modern luvar. A later reexamination of the specimens showed that they were too incomplete to demonstrate such a conclusion and had no clear exclusive shared traits with luvar, and were renamed "Aluvarus", meaning "not luvar" or "different than luvar". However, some authorities still retain it as a luvar.
Anaethalion is an extinct genus of prehistoric marine and freshwater ray-finned fish related to modern tarpons and ladyfish. It is known from the Late Jurassic to the Early Cretaceous of Europe and northeasterrn Asia, roughly encompassing the Tethys Ocean.
Cylindracanthus is an extinct genus of Cretaceous to Eocene aged ray-finned fish. It is almost exclusively known from bony rostrum fragments as well as some associated teeth, with the rest of the skeleton being cartilaginous. While originally considered to be closely related to billfish, the structure of its rostrum is dissimilar, and is unlikely to be closely related, some later studies suggested closer affinities to the Acipenseriformes. However, this was later rejected due to the lack of osteocytes in histologically examined specimens, which resembles the condition of derived teleosts. A close relation to Blochius has been suggested.
Xiphiorhynchus is an extinct genus of prehistoric swordfish that lived from the Eocene until the Oligocene. Unlike the modern swordfish, both the upper and lower jaws of Xiphiorhynchus were extended into blade-like points.
Notogoneus is an extinct genus of prehistoric ray-finned fish. A trace fossil attributed to Notogoneus osculus has been found in the Green River Formation.
Palimphyes is an extinct genus of prehistoric euzaphlegid bony fish related to the escolars and snake mackerels. The various species lived as deepwater mesopelagic predators in the Tethys and Paratethys oceans, with fossils of ten species found in Paleocene to Oligocene strata of the Swiss Alps, the Carpathian and Caucasus Mountains, Iran, India, and Turkmenistan.
Pleuropholis is an extinct genus of prehistoric ray-finned fish.
