''Pholidophorus'' (from el, φολῐ́ς , 'horny scale' and el, φέρω , 'to bear') is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus of

stem Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...

teleost Teleostei (; Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts ), is, by far, the largest infraclass in the class Actinopterygii, the ray-finned fishes, containing 96% of all extant species of fish. Tel ...

fish. Numerous species were assigned to this genus in the past, but only the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

''Pholidophorus latiusculus'', from the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...

of Europe, is considered to be a valid member of the genus today.

Taxonomy

The genus ''Pholidophorus'' for a long time served as a

wastebasket taxon Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined ...

containing various unrelated species of basal stem-teleosts. Over the years, many of these have been moved to separate genera. The Late Jurassic nominal species ''"Pholidophorus" purbeckensis'' was renamed '' Ichthyokentema'' by Arthur Woodward in 1941. Likewise, the Early Jurassic form ''"Pholidophorus" bechei'' was renamed '' Dorsetichthys'' and moved to its own family, Dorsetichthyidae, by Arratia (2013). The nominal species ''"Pholidophorus" friedeni'' Delsate, 1999 and ''"Pholidophorus" gervasuttii'' Zambelli, 1980 were renamed '' Luxembourgichthys'' and '' Lombardichthys'' by Taverne and Steurbaut (2017) and Arratia (2017) respectively.

Description

''Pholidophorus'' was a

herring Herring are forage fish, mostly belonging to the family of Clupeidae. Herring often move in large schools around fishing banks and near the coast, found particularly in shallow, temperate waters of the North Pacific and North Atlantic Oceans, i ...

-like fish about long, although it was not closely related to modern herring. Like them, however, it had a single

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

, a symmetrical tail, and an

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

placed towards the rear of the body. It had large eyes and was probably a fast-swimming predator, hunting

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s and smaller fish. A very early teleost, ''Pholidophorus'' had many primitive characteristics such as

ganoid scale A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as we ...

s and a spine that was partially composed of

cartilage Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck an ...

, rather than

bone A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provid ...

References

Pholidophoridae Monotypic ray-finned fish genera Prehistoric ray-finned fish genera Norian genera Triassic bony fish Late Triassic fish of Europe Fossil taxa described in 1832 Taxa named by Louis Agassiz {{Triassic-fish-stub