The Devonian is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.3 million years from the end of the preceding Silurian period at 419.2 million years ago (Ma), to the beginning of the succeeding Carboniferous period at 358.9 Ma. It is named after Devon, South West England, where rocks from this period were first studied.
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.
Dunkleosteus is an extinct genus of large arthrodire ("jointed-neck") fish that existed during the Late Devonian period, about 382–358 million years ago. It was a pelagic fish inhabiting open waters, and one of the first apex predators of any ecosystem.
Cephalaspis is a possibly monotypic genus of extinct osteostracan agnathan vertebrate. It was a trout-sized detritivorous fish that lived in the early Devonian.
Drepanaspis is an extinct genus of primitive jawless Ostracoderms from the Early Devonian that belonged to the phylum Chordata, infraphylum Agnatha, class Pteraspidomorphi, and the subclass Heterostraci. Drepanaspis are assumed to have lived primarily in marine environments and is most commonly characterized by their ray-like, heavily armored bodies, along with their lack of paired fins and jaws.
Cheirolepis is an extinct genus of ray-finned fish that lived in the Devonian period of Europe and North America. It is the only genus yet known within the family Cheirolepidae and the order Cheirolepiformes. It was among the most basal of the Devonian actinopterygians and is considered the first to possess the "standard" dermal cranial bones seen in later actinopterygians.
Holoptychius is an extinct genus of porolepiform lobe-finned fish from the Middle Devonian to Carboniferous (Mississippian) periods. It is known from fossils worldwide. The genus was first described by Louis Agassiz in 1839.
Mesacanthus is an extinct genus of acanthodian fish from early Devonian Scotland. It is among the more primitive of the Devonian acanthodians.
The Palaeonisciformes, commonly known as "palaeoniscoids" are an extinct grouping of primitive ray-finned fish (Actinopterygii), spanning from the Silurian/Devonian to the Cretaceous. 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, it has been suggested that some may belong to the crown group, with some of these possibly related to Cladistia and/or Chondrostei. Many palaeoniscoids share a conservative body shape and a similar arrangement of skull bones.
Phlyctaeniidae is an extinct family of placoderm arthrodire fishes that lived during the Devonian period, mainly in Norway and North America.
Cartieraspis is an extinct genus of Phlyctaeniid placoderm fish which lived during the Middle Devonian period in North America. Whether or not it is morphologically different enough from its close relative and contemporary Phlyctaenius to be considered generically distinct is dubious.
Tristichopterus, with a maximum length of sixty centimetres, is the smallest genus in the family of prehistoric lobe-finned fish, Tristichopteridae that was believed to have originated in the north and dispersed throughout the course of the Upper Devonian into Gondwana. Tristichopterus currently has only one named species, first described by Egerton in 1861. The Tristichopterus node is thought to have originated during the Givetian part of the Devonian. Tristichopterus was thought by Egerton to be unique for its time period as a fish with ossified vertebral centers, breaking the persistent notochord rule of most Devonian fish but this was later reinspected and shown to be only partial ossification by Dr. R. H. Traquair. Tristichopterus alatus closely resembles Eusthenopteron and this sparked some debate after its discovery as to whether it was a separate taxon.
Pentlandia is an extinct genus of prehistoric sarcopterygians or lobe-finned fish. Its first discovered species was initially named Dipterus macroptera by Ramsay Traquair in 1888, then renamed Pentlandia macroptera by D.M.S. Watson and H. Day in 1916.
Acentrophorus is an extinct genus of prehistoric ray-finned fish from the Wuchiapingian of England and Germany (Kupferschiefer). There may also be a Triassic occurrence in Australia.
Rhadinichthys is an extinct genus of prehistoric bony fish. It is known from several species that lived in the Late Devonian epoch, the Carboniferous period and the Cisuralian epoch in what is now Europe, South Africa, and North and South America. Some isolated scales from the Cisuralian of Europe were also referred to this genus.
Heightingtonaspis is an extinct genus of primitive arthrodire placoderm fish from the Devonian period in Great Britain, and currently contains three species.
This timeline of eurypterid research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and taxonomic revisions of eurypterids, a group of extinct aquatic arthropods closely related to modern arachnids and horseshoe crabs that lived during the Paleozoic Era.
Diplacanthus is an extinct genus of Mid to Late Devonian fish in the class Acanthodii, known as spiny sharks.
