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.
Axelrodichthys is an extinct genus of mawsoniid coelacanth from the Cretaceous of Africa, North and South America, and Europe. Several species are known, the remains of which were discovered in the Lower Cretaceous (Aptian-Albian) of Brazil, North Africa, and possibly Mexico, as well as in the Upper Cretaceous of Morocco (Cenomanian), Madagascar and France. The Axelrodichthys of the Lower Cretaceous frequented both brackish and coastal marine waters while the most recent species lived exclusively in fresh waters. The French specimens are the last known fresh water coelacanths. Most of the species of this genus reached 1 metre to 2 metres in length. Axelrodichthys was named in 1986 by John G. Maisey in honor of the American ichthyologist Herbert R. Axelrod.
Mawsonia is an extinct genus of prehistoric coelacanth fish. It is amongst the largest of all coelacanths, with one quadrate specimen possibly belonging to an individual measuring 5.3 metres in length. It lived in freshwater and brackish environments from the late Jurassic to the mid-Cretaceous of South America, eastern North America, and Africa. Mawsonia was first described by British paleontologist Arthur Smith Woodward in 1907.
Mawsoniidae is an extinct family of prehistoric coelacanth fishes which lived during the Triassic to Cretaceous periods. Members of the family are distinguished from their sister group, the Latimeriidae by the presence of ossified ribs, a coarse rugose texture on the dermatocranium and cheek bones, the absence of the suboperculum and the spiracular, and reduction or loss of the descending process of the supratemporal. Mawsoniids are known from North America, Europe, South America, Africa, Madagascar and Asia. Unlike Latimeriidae, which are exclusively marine, Mawsoniidae were also native to freshwater and brackish environments. Mawsoniids represent among the youngest known coelacanths, with the youngest known remains of the freshwater genus Axelrodichthys from France and an indeterminate marine species from Morocco being from the final stage of the Cretaceous, the Maastrichtian, roughly equivalent in age to the youngest known fossils of latimeriids. Species of Mawsonia and Trachymetopon are known to have exceeded 5 metres in length, making them among the largest known bony fish to have ever existed.
Aidachar is an extinct genus of marine ichthyodectiform ray-finned fish from the Late Cretaceous (Cenomanian-Turonian) of Central Asia and North Africa.
The Kem Kem Group is a geological group in the Kem Kem region of eastern Morocco, whose strata date back to the Cenomanian stage of the Late Cretaceous. Its strata are subdivided into two geological formations, with the lower Ifezouane Formation and the upper Aoufous Formation used for the strata on the eastern side of the Atlas Mountains (Tinghir), with the Gara Sbaa Formation and Douira Formation used in the southern Tafilalt region. It is exposed on an escarpment along the Algeria–Morocco border.
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.
Enchelion is an extinct genus of prehistoric marine ray-finned fish that lived during the Late Cretaceous. It contains a single species, E. montium known from the upper Cenomanian of the Haqel locality of the Sannine Formation in Lebanon. It is the only member of the family Encheliidae.
Casierius is an extinct genus of marine ray-finned fish that lived during the Albian stage of the Early Cretaceous epoch. It was a relative of the modern bonefish in the extinct family Phyllodontidae, although some authorities consider it either a true albulid or a very early eel. It contains a single species, C. heckeli, known from the Glen Rose Formation near Hood County, Texas.
Stromerichthys is an extinct genus of potentially chimaeric freshwater bony fish that lived during the Late Cretaceous epoch. It contains a single species, S. aethiopicus, described from a now-lost specimen with bones & scales from Egypt.
Chrotichthys is an extinct genus of prehistoric freshwater ray-finned fish that lived in the Anisian stage of the Middle Triassic epoch. It contains a single species, C. gregarius, known from the Terrigal Formation of New South Wales, Australia.
Trachymetopon is an extinct genus of prehistoric coelacanth from the Jurassic of Europe. Fossils have been found in the Early Jurassic Posidonia Shale of Germany the Middle Jurassic Marnes de Dives of France, and probably the Late Jurassic Kimmeridge Clay of England. Only one species has been named, Trachymetoponliassicum, described by Henning in 1951 from an almost complete specimen found in the Lower Toarcian of Ohmden in Baden-Württemberg. Another specimen is known from the same site, and two older specimens come from the Sinemurian of Holzmaden. The holotype of this species is 1.6 metres in length. A giant specimen of an undetermined species of Trachymetopon found at the Middle Jurassic Falaises des Vaches Noires of Normandy. This specimen, composed of a 53 cm long palatoquadrate, belongs to an individual 4 metres (13 ft) in length. A basisphenoid found in a museum in Switzerland that likely originates from the same locaity probably belonged to an individual around 5 m (16 ft) long, making Trachymetopon the largest of all coelacanths alongside Mawsonia. A study published in 2015 revealed that this coelacanth belongs to the Mawsoniidae. Trachymetopon is one of the few known mawsoniids to have been exclusively marine, while most of the other members of the group have lived in fresh and brackish waters.
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.
Cylindracanthus is an extinct, enigmatic genus of marine ray-finned fish with fossils known throughout North America, Europe, Asia and Africa from the Late Cretaceous to the late Eocene, with potential Oligocene records and a possible Miocene record also known. It is exclusively known from its distinctive partial remains, which are long cylindrical bony spines that are usually considered rostrum fragments, as well as some associated teeth. These spines are abundant & widespread throughout this timespan, and are useful indicators of a nearshore marine environment, but the taxonomic identity of the fish is still highly uncertain and debated.
Psilichthys is an extinct genus of prehistoric bony fish from Eumeralla Formation, the Lower Cretaceous epoch of what is now Victoria, Australia, known from single species P. selwyni. This is the first Mesozoic fossil vertebrate named from Victoria.
Elopoides is an extinct genus of prehistoric marine ray-finned fish known from the Early Cretaceous of Europe. It contains a single species, E. tomassoni, known from the late Albian of Aube, France. It is thought to be a stem-group megalopid, making it closely related to modern tarpons.
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.
Goulmimichthys is an extinct genus of ray-finned fishes in the family Pachyrhizodontidae. The genus, first described by Cavin in 1995, is known from various Turonian age formations. The type species G. arambourgi from the Akrabou Formation in the El Rachidia Province of Morocco, and other fossils described are G. gasparini of the La Frontera Formation, Colombia, and G. roberti from the Agua Nueva Formation of Mexico.
Oniichthys is an extinct genus of gar in the family Lepisosteidae. It contains a single species, O. falipoui, known from the Late Cretaceous (Cenomanian) of Morocco.
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.
