| Sphenonectris | |
|---|---|
 | |
| An artist's concept of Sphenonectris. | |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Order: | |
| Family: | |
| Genus: | Sphenonectris |
| Species | |
Sphenonectris turnerae [1] | |
Sphenonectris is an extinct genus of thelodont, which lived in Canada during the Early Devonian period.
Sphenonectris possessed a hunched pomacanthid-like body with the only visible fin being the caudal fin.
The coelacanths are members of a now-rare order of fish (Coelacanthiformes) that includes two extant species in the genus Latimeria: the West Indian Ocean coelacanth, primarily found near the Comoro Islands off the east coast of Africa, and the Indonesian coelacanth. The name originates from the Permian genus Coelacanthus, which was the first scientifically named coelacanth.
Salmonidae is a family of ray-finned fish, the only living family currently placed in the order Salmoniformes. It includes salmon, trout, chars, freshwater whitefishes, and graylings, which collectively are known as the salmonids. The Atlantic salmon and trout of the genus Salmo gives the family and order their names.
The bullhead sharks are a small order of modern sharks (Neoselachii). The nine living species are placed in a single genus, Heterodontus, in the family Heterodontidae. All are relatively small, with the largest species reaching just 1.65 metres (5.5 ft) in maximum length. They are bottom feeders in tropical and subtropical waters.
Gnathostomata are the jawed vertebrates. The term derives from Greek: γνάθος "jaw" + στόμα "mouth". Gnathostome diversity comprises roughly 60,000 species, which accounts for 99% of all living vertebrates. In addition to opposing jaws, living gnathostomes have true teeth, paired appendages, the elastomeric protein of elastin, and a horizontal semicircular canal of the inner ear, along with physiological and cellular anatomical characters such as the myelin sheaths of neurons, and an adaptive immune system that has the discrete lymphoid organs of spleen and thymus, and uses V(D)J recombination to create antigen recognition sites, rather than using genetic recombination in the variable lymphocyte receptor gene.
Lungfish are freshwater rhipidistian vertebrates belonging to the order Dipnoi. Lungfish are best known for retaining ancestral characteristics within the Osteichthyes, including the ability to breathe air, and ancestral structures within Sarcopterygii, including the presence of lobed fins with a well-developed internal skeleton. Lungfish represent the closest living relatives of the tetrapods.
Ichthyosaurs are large extinct marine reptiles. Ichthyosaurs belong to the order known as Ichthyosauria or Ichthyopterygia.
Balaenoptera, from Latin: balaena ('whale') and Ancient Greek: pteron ('fin'), is a genus of rorquals, and contains eight extant species. Balaenoptera comprises all but two of the extant species in its family ; the genus is currently polyphyletic, with the two aforementioned species being phylogenetically nested within it.
Aulopiformes is a diverse order of marine ray-finned fish consisting of some 15 extant and several prehistoric families with about 45 genera and over 230 species. The common names grinners, lizardfishes and allies, or aulopiforms are sometimes used for this group. The scientific name means "Aulopus-shaped", from Aulopus + the standard fish order suffix "-formes". It ultimately derives from Ancient Greek aulós + Latin forma, the former in reference to the elongated shape of many aulopiforms.
Holocephali, sometimes given the term Euchondrocephali, is a subclass of cartilaginous fish in the class Chondrichthyes. The earliest fossils are of teeth and come from the Devonian period. Little is known about these primitive forms, and the only surviving group in the subclass is the order Chimaeriformes.
Apsopelix is an extinct genus of ray-finned fish that existed about 95-80 million years ago in the shallow waters of the Western Interior Seaway, Hudson Seaway, and Japan. Average length was about 1.5 feet or 10–12 cm, most likely they lived in schools but are seldom preserved as fossils.
Tiktaalik is a monospecific genus of extinct sarcopterygian from the Late Devonian Period, about 375 Mya, having many features akin to those of tetrapods.
Elpistostege is an extinct genus of finned tetrapodomorphs that lived during the late Givetian to early Frasnian ages of the Late Devonian epoch. Its only known species, E. watsoni, was first described in 1938 by the British palaeontologist Thomas Stanley Westoll, based on a single partial skull roof discovered at the Escuminac Formation in Quebec, Canada.
Mandageria fairfaxi is an extinct lobe-finned fish that lived during the Late Devonian period. It is related to the much larger Hyneria; although Mandageria was smaller, it probably hunted in the same way.
Birgeria is a genus of carnivorous marine ray-finned fish from the Triassic period. Birgeria had a global distribution. Fossils were found in Madagascar, Spitsbergen, Germany, Switzerland, Italy, Slovenia, China, Russia, Canada and Nevada, United States. The oldest fossils are from Griesbachian aged beds of the Wordie Creek Formation of East Greenland.
Elpistostegalia or Panderichthyida is an order of prehistoric lobe-finned fishes which lived during the Late Devonian period. They represent the advanced tetrapodomorph stock, the fishes more closely related to tetrapods than the osteolepiform fishes. The earliest elpistostegalians, combining fishlike and tetrapod-like characters, are sometimes called fishapods, a phrase coined for the advanced elpistostegalian Tiktaalik. Through a strict cladistic view, the order includes the terrestrial tetrapods.
Laytonia is an extinct genus of prehistoric halosaur that lived in deep water off the North American Pacific Coast from the Zemorrian Epoch until during the Upper Miocene subepoch, when tectonic uplift effectively destroyed the genus' habitat by making the deep water too shallow.
Batoidea is a superorder of cartilaginous fishes, commonly known as rays. They and their close relatives, the sharks, comprise the subclass Elasmobranchii. Rays are the largest group of cartilaginous fishes, with well over 600 species in 26 families. Rays are distinguished by their flattened bodies, enlarged pectoral fins that are fused to the head, and gill slits that are placed on their ventral surfaces.
Tarasiiformes is an extinct order of prehistoric ray-finned fish.
Bobasatraniiformes is an extinct order of durophagous ray-finned fish that existed from the late Permian to the Middle Triassic in both marine and freshwater environments. The order includes two families: Bobasatraniidae, with the genera Bobasatrania, Ebenaqua, and Ecrinesomus, and Dorypteridae, comprising only the genus Dorypterus (monotypy). Bobasatraniiformes had a somewhat global distribution; fossils are found in Africa (Madagascar), Asia (Pakistan), Australia, Europe, and North America.
The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fish lineages belong to the Agnatha, or jawless fish. Early examples include Haikouichthys. During the late Cambrian, eel-like jawless fish called the conodonts, and small mostly armoured fish known as ostracoderms, first appeared. Most jawless fish are now extinct; but the extant lampreys may approximate ancient pre-jawed fish. Lampreys belong to the Cyclostomata, which includes the extant hagfish, and this group may have split early on from other agnathans.
 | This article related to a Devonian jawless fish is a stub. You can help Wikipedia by expanding it. |
