WArduodens is an extinct genus of ctenacanth fish from the Devonian period. Its name is derived from the Latin Arduus meaning steep and dens meaning tooth. It is currently known from a singular species, A. flammeus. It was described from isolated cladodont teeth found in deposits from the upper Frasnian to lower Fammenian of central Iran. The specific epithet is derived from the Latin for "flamming."
WBrochoadmones is an extinct genus of acanthodian from the Devonian of what is now Canada. It is the only genus in the suborder Brochoadmonoidea, whose relationship to other acanthodian orders remains currently in flux.
WCheiracanthus is an extinct genus of a group of fish called Acanthodii. It was a deep-bodied acanthodian about 12 in. (30 cm) in length. It had a blunt head, upturned tail, and fins protected by spines. Unlike many other acanthodians, it had one, solitary dorsal fin. Cheiracanthus swam at mid-depth in lakes and rivers, seizing small prey in its gaping jaws. Whole fossils of this fish occur only in Mid-Devonian rocks in Scotland, but its distinctive small, ornamented scales crop up around the world, as far south as Antarctica.
WThe Climatiiformes is an order of extinct fish belonging to the class Acanthodii. Like most other "spiny sharks", the Climatiiformes had sharp spines. These animals were often fairly small in size and lived from the Late Silurian to the Early Carboniferous period. The type genus is Climatius. The order used to be subdivided into the suborders Climatiida and Diplacanthida, but subsequently Diplacanthida has been elevated to a separate order, the Diplacanthiformes. The Diplacanthiformes take their name from Diplacanthus, first described by Agassiz in 1843.
WClimatius is an extinct genus of spiny shark. Fossils have been found in both Europe and North America.
WGyracanthides is an extinct genus of large acanthodian fish.
WGyracanthus is an extinct genus of acanthodian.
WIberotrygon is an extinct genus of sclerorhynchiform ray from the Cenomanian Mosqueruela Formation of Spain. Only the single species I. plagiolophus, is known; it was named and described in 2009. It is known from the holotype MPZ 2005-33, an antero-lateral tooth, and the parartypes MPZ 2005-34, four well-preserved teeth from a single juvenile, and MPZ 2005-35, an isolated tooth.
WAn ichthyolith is any disarticulated remains of a fish found in the fossil record, most often a scale, denticle or tooth.
WIschanacanthiformes is an order of Acanthodii or spiny sharks found in Canada, Ukraine and United Kingdom. Members of this order were nektonic carnivores, eating animals that swim rather than plankton. They had slender builds, light armor, deeply inserted spines, shark-like teeth, and two dorsal fins. Some species were around 2 meters long. It was described by Berg in 1940.
WIschnacanthus is an extinct genus of jawed fish in the class Acanthodii. It lived during the Early Devonian period, approximately 421–409 million years ago. It is known from a single species, which is also the type species, I. gracilis.
WMesacanthus is an extinct genus of acanthodian fish from early Devonian Scotland. It is among the more primitive of the Devonian acanthodians.
WNerepisacanthus is an extinct genus of acanthodian, probably acritolepid, from Middle Silurian deposits of New Brunswick, Canada. Nerepisacanthus is known from many incomplete but articulated specimens. It was collected from the Cunningham Creek Formation, near Nerepis, southern New Brunswick. It was first named by Carole J. Burrow in 2011 and the type species is Nerepisacanthus denisoni.
WNostolepis is an extinct genus of acanthodian fish which lived in the Late Silurian (Pridoli) to Middle Devonian (Lochkovian). Members of the genus include Nostolepis gracilis and Nostolepis striata.
WParexus is an extinct genus of acanthodian fish. Acanthodians are often referred to as ‘spiny sharks’, although acanthodians are not true sharks and evolved perhaps 50 million years earlier than sharks. Acanthodians share several features with bony fish and cartilaginous fish; they often have spines supporting their fins.
WVeridagon avendanoi is an extinct aulopiform ray-finned fish related to species of Enchodus from the Cenomanian-aged Cintalapa Formation, exposed in El Chango Quarry, Chiapas, Mexico. Its original generic name was Dagon; however, this name was preoccupied by a group of South American butterflies. The generic name was eventually amended to Veridagon.