Prehistoric ray-finned fish orders

Semionotiformes is an order of ray-finned fish known from the Middle Triassic (Anisian) to the Late Cretaceous (Maastrichtian). Their closest living relatives are gars (Lepisosteidae), with both groups belonging to the clade Ginglymodi within the Holostei. The group includes both freshwater (Semionotidae) and marine (Callipurbeckiidae, Macrosemiidae) adapted forms. Many members of the family Macrosemiidae (which are usually included in Semionotiformes but sometimes placed in their order), had elongated dorsal fins, often associated with an adjacent area of skin which was free of scales. These

Pachycormiformes is an extinct order of marine ray-finned fish known from the Early Jurassic to the end of the Cretaceous. Depending on the treatment, it only includes a single family, Pachycormidae, or two families: the mostly filter-feeding Pachycormidae and the carnivorous Protosphyraenidae. They were characterized by having serrated pectoral fins (though more recent studies demonstrated that fin shape diversity in this group was high), reduced pelvic fins and a bony rostrum. Pachycormiformes are morphologically diverse, containing both tuna and swordfish-like carnivorous forms, as well as

Pycnodontiformes is an extinct order of primarily marine bony fish. The group first appeared during the Late Triassic and disappeared during the Eocene. The group has been found in rock formations in Africa, Asia, Europe, North and South America.

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.

Palaeoniscoids (also spelled paleoniscoid, or alternatively paleoniscids) are an extinct grouping of primitive ray-finned fish (Actinopterygii), spanning from the Silurian/Devonian to the Cretaceous. Though often assigned to their own order, the Palaeonisciformes (or superorder Palaeoniscimorpha), they are generally considered paraphyletic, but their exact relationships to living ray-finned fish are uncertain. While some and perhaps most palaeoniscoids likely belong to the stem-group of Actinopteryii (less closely related to modern ray-finned fish groups than all modern ray-finned fish are to

REDIRECT Aspidorhynchidae

The Ellimmichthyiformes, also known as double-armored herrings, are an extinct order of ray-finned fish known from the Late Jurassic to the Oligocene. They were the sister group to the extant true herrings, shad and anchovies in the order Clupeiformes, with both orders belonging to the suborder Clupeomorpha. Some studies suggest that the order may be potentially paraphyletic with respect to crown-group Clupeiformes.

Tselfatiiformes is an extinct order of bony fishes from the infraclass Teleostei. The order represents the most important radiation of marine teleosts during the Cretaceous period. Fossils of tselfatiiforms are known from Europe, North America, central and northern South America, the Middle East and North Africa.

left|thumb|Fin shape diversity within Macrosemiiformes A. Propterus microstomus; B. Notagogus denticulatus; C. Legnonotus krambergeri; D. Macrosemius rostratus; E. Enchelyolepis andrewsi F. Enchelyolepis pectoralis G. Uarbryichthys latus H. Voelklichthys comitatus. Pectoral fins are shown in yellow; pelvic fins in orange; dorsal fins in red; and anal fins in green.

Ionoscopiformes is an extinct order of largely marine, ray-finned fish generally considered to be the sister group to Amiiformes, an order that contains the modern Bowfin. The earliest members of the order are found in Middle Triassic deposits in all continents besides Australia and Antarctica, showing that the group was very widespread even during this time. They would continue to diversify throughout the Jurassic and Cretaceous with the youngest records of the group being during the Albian. The order has had a complicated taxonomic history since the 2010s with authors suggesting that the gro

Perleidiformes are an extinct order of prehistoric ray-finned fish from the Triassic period Although numerous Triassic taxa have been referred to Perleidiformes, which ones should be included for it to form a monophyletic group is a matter of ongoing scientific debate. thumb|Chaohuperleidus primus, one of the earliest perleidids

Crossognathiformes is an extinct order of ray-finned fish that lived from the Late Jurassic to the Eocene. Its phylogenetic placement is disputed; some authors have recovered it as part of the teleost stem group, while others place it in a basal position within crown group Teleostei. Other placements have found it to be polyphyletic, with Varasichthyidae being stem-group teleosts whereas the other, "true" crossognathiforms are crown-group teleosts within Teleocephala.

thumb|right|The Triassic [[Saurichthys was a highly specialized predator]] thumb|right|Saurichthys|Costasaurichthys paucitrichus fossil thumb|right|Saurichthys|Saurichthys curionii fossil thumb|right|Fossil of the Jurassic saurichthyid Saurorhynchus brevirostris thumb|right|Morphological comparison of Saurichthyidae with extant needlefish and flying fish. A. Sinosaurichthys|Sinosaurichthys longipectoralis; B. Sinosaurichthys longimedialis; C. Sinosaurichthys minuta; D. Saurichthys dawaziensis from Middle Triassic of Dawazi Section, Luoping, Yunnan, China (based on Wu et al. 2009). E. Atlantic