Basilosaurus is a genus of large, predatory, prehistoric archaeocete whale from the late Eocene, approximately 41.3 to 33.9 million years ago (mya). First described in 1834, it was the first archaeocete and prehistoric whale known to science. Fossils attributed to the type species B. cetoides were discovered in the United States. They were originally thought to be of a giant reptile, hence the suffix "-saurus", Ancient Greek for "lizard". The animal was later found to be an early marine mammal, which prompted attempts at renaming the creature, which failed as the rules of zoological nomenclature dictate using the original name given. Fossils were later found of the second species, B. isis, in 1904 in Egypt, Western Sahara, Morocco, Jordan, Tunisia, and Pakistan. Fossils have also been unearthed in the southeastern United States and Peru.
Dorudon ("spear-tooth") is a genus of extinct basilosaurid ancient whales that lived alongside Basilosaurus 40.4 to 33.9 million years ago in the Eocene. It was a small whale, with D. atrox measuring 5 metres (16 ft) long and weighing 1–2.2 metric tons. Dorudon lived in warm seas around the world and fed on small fish and mollusks. Fossils have been found along the former shorelines of the Tethys Sea in present-day Egypt and Pakistan, as well as in the United States, New Zealand and Western Sahara.
Oxyaena is an extinct genus of placental mammals from extinct subfamily Oxyaeninae within extinct family Oxyaenidae, that lived in Europe, Asia and North America during the early Eocene.
Amblypterus is an extinct genus of freshwater ray-finned fish that lived during the Gzhelian and Cisuralian epoch in what is now Europe and possibly India and Argentina. Potential indeterminate records stretch as far back as the early Carboniferous.
Eothynnus salmonens is an extinct species of prehistoric jackfish that lived during the lower Eocene of what is now the Isle of Sheppey (as a part of the London Clay Lagerstatten. It is known exclusively from some preserved skulls.
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.
Promegalops is an extinct genus of prehistoric bony fish that lived during the lower Eocene.
Protarpon is an extinct genus of prehistoric bony fish that lived during the lower Eocene.
Pteronisculus is an extinct genus of prehistoric ray-finned fish that lived during the Early Triassic and Middle Triassic epochs of the Triassic period worldwide.
Crenilepis is an extinct genus of prehistoric bony fish that lived in the seas of present-day Europe during the Anisian stage of the Middle Triassic epoch.
Caruichthys is an extinct genus of prehistoric bony fish that lived during the Early Triassic epoch in what is now South Africa. It is known from a single specimen, which was collected from the middle Beaufort Series of Doorn River.
Eolactoria sorbinii is an extinct prehistoric boxfish that lived during the Lutetian epoch of the middle Eocene, in Monte Bolca. It had two pairs of long spines, one over each eye, and one pair beneath the anal and caudal fins, arranged very similarly to those possessed by the modern genus Lactoria, but were, in comparison, much longer. E. sorbinii had a fifth spine between the two eye-spines, arranged and looking very much like a nose.
Joleaudichthys is an extinct genus of prehistoric flatfish that lived from the early to middle Eocene of Egypt.
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.
Haplolepis is an extinct genus of prehistoric ray-finned fish that lived during the late Moscovian Stage of the Pennsylvanian Period. Well-preserved specimens are known from the Lagerstätte in the Upper Freeport Coal at Linton, Ohio, and were first described by John Strong Newberry in the 1800s.
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.
Bobasatrania is an extinct genus of prehistoric marine ray-finned fish that survived the Permian-Triassic extinction event. Fossils of Bobasatrania were found in beds of Changhsingian to Ladinian age. It was most speciose during the Early Triassic.
Ctenothrissa is a prehistoric genus of ray-finned fish in the supposed order "Ctenothrissiformes".
Urosthenes is an extinct genus of prehistoric bony fish that lived during the Lopingian to Middle Triassic epochs in what is now New South Wales, Australia.
Ichthyokentema ("fish-goad") is an extinct genus of stem-teleost fish that lived during the Late Jurassic. It contains one species, I. purbeckensis, which is known from the Purbeck Group of Dorset, England. I. purbeckensis was originally described as a species of Pholidophorus by William Davies in 1887, but was moved to its own genus by Arthur Smith Woodward in 1941.
