The Amiiformes order of fish has only two extant species, the bowfins: Amia calva and Amia ocellicauda, the latter recognized as a separate species in 2022. These Amiiformes are found in the freshwater systems of North America, in the United States and parts of southern Canada. They live in freshwater streams, rivers, and swamps. The order first appeared in the Triassic, and the extinct members include both marine and freshwater species, many of which are morphologically disparate from bowfins, such as the caturids.
Acropomatidae is a family of fish in the order Perciformes, commonly known as lanternbellies. Acropoma species are notable for having light-emitting organs along their undersides. They are found in all temperate and tropical oceans, usually at depths of several hundred meters. There are about 32 species in as many as 9 genera, although some authorities recognise fewer genera than Fishbase does.
Arandaspida is a taxon of very early, jawless prehistoric fish which lived during the Ordovician period. Arandaspids represent the oldest known craniates, a proposed group of chordates that contain all chordates with a cartilage-derived skull, and hagfish. The group represents a subclass within the class Pteraspidomorphi, and contains only one order, the Arandaspidiformes. The oldest known genus of this group is Sacabambaspis found in South America.
Thelodonti is a class of extinct Palaeozoic jawless fishes with distinctive scales instead of large plates of armor.
Anaspida is an extinct group of jawless fish that existed from the early Silurian period to the late Devonian period. They were classically regarded as the ancestors of lampreys, but it is denied in recent phylogenetic analysis, although some analysis show these group would be at least related. Anaspids were small marine fish that lacked a heavy bony shield and paired fins, but were distinctively hypocercal.
Eriptychiida is an extinct marine taxon of vertebrate in the group Pteraspidomorphi.
Percopsidae is a family of fish in the order Percopsiformes, with one extant genus with two species, both endemic to North America, and two known fossil genera.
Astraspida, or astraspids, are a small group of extinct armored jawless vertebrates, which lived in the Middle Ordovician in North America. They are placed among the Pteraspidomorphi because of the large dorsal and ventral shield of their head armor. They are represented by a single genus, Astraspis, including possibly two species, A. desiderata and A. splendens but their remains are fairly abundant in Ordovician sandstones of the USA and Canada (Quebec). The head armor of Astraspis is rather massive, with a series of ten gill openings lining the margin of the dorsal shield, and laterally placed eyes. The dorsal shield is ribbed by strong longitudinal crests, and the tail is covered with large, diamond-shaped scales. They are often grouped together with the Arandaspidida.
Rhyncholepis was an extinct genus of anaspida from the Late Silurian. Fossils of species R. butriangula and R. parvula have been found in Ringerike, Norway, and Oesel, Estonia. The genus has two species, described in 1911 and 2002.
Ptycholepiformes are an extinct order of prehistoric ray-finned fish that existed during the Triassic period and the Early Jurassic epoch. The order includes the genera Acrorhabdus, Ardoreosomus, Boreosomus, Chungkingichthys, Ptycholepis, and Yuchoulepis. Although several families have been proposed, some studies place all these genera in the same family, Ptycholepididae.
Tarasiiformes is an extinct order of prehistoric ray-finned fish.
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.
Peltopleuriformes is an extinct order of ray-finned fish.
Peltopleuridae were an extinct family of prehistoric bony fish. It is classified with the order Peltopleuriformes.
Thoracopteridae is an extinct family of prehistoric bony fish; classified with the order Peltopleuriformes. This lineage of Triassic flying fish-like Perleidiformes converted their pectoral and pelvic fins into broad wings very similar to those of their modern counterparts. However, this group is not related to modern flying fish from the family Exocoetidae, instead being a case of convergent evolution.
Myllokunmingiidae is a group of very early, jawless prehistoric fish (Agnathans) which lived during the Cambrian period. The Myllokunmingiids are the earliest known group of craniates. The group contains three genera, Haikouichthys, Myllokunmingia, and Zhongjianichthys. Their fossils have been found only in the Maotianshan Shales lagerstätte.
Birkeniiformes is an extinct order of jawless fish belonging to the class Anaspida.
The Procatopodini is an African tribe of fishes, it is part of the subfamily Procatopodinae, within the family Poeciliidae.
The Girardini is a tribe of killifishes from the "livebearer" family Poeciliidae, consisting of three genera and 10 species. The tribe was originally delineated by Carl Leavitt Hubbs in 1924.
Tahulalepididae is an extinct family of jawless fish belonging to the order Birkeniiformes.
