''Bellerophon'' is a genus of extinct paleozoic marine molluscs of uncertain position (

Gastropoda The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. Th ...

Monoplacophora Monoplacophora , meaning "bearing one plate", is a polyphyletic superclass of molluscs with a cap-like shell inhabiting deep sea environments . Extant representatives were not recognized as such until 1952; previously they were known only from ...

) in the family Bellerophontidae. The genus was named after

Bellerophon Bellerophon (; Ancient Greek: Βελλεροφῶν) or Bellerophontes (), born as Hipponous, was a hero of Greek mythology. He was "the greatest hero and slayer of monsters, alongside Cadmus and Perseus, before the days of Heracles", and his ...

, the ancient Greek hero. ''Bellerophon'' is the

type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal ...

of the family Bellerophontidae.

Shell description

The genus is characterised by a shell which is globose, convolute, and planispiral (symmetrically coiled). The shell of ''Bellerophon'' superficially resembles that of a miniature

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, a ...

(e.g. '' Nautilus'' or an

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish ...

), except that septa are lacking. The shell of ''Bellerophon'' is often a couple of centimeters in maximum dimension. The external surface is smooth, ornamented only by

growth lines Growth arrest lines, also known as Harris lines, are lines of increased bone density that represent the position of the growth plate at the time of insult to the organism and formed on long bones due to growth arrest. They are only visible by radi ...

. There is a low crest or ridge running along the midline of the shell. Many specimens of ''Bellerophon'' show something resembling a "waterline" about halfway up the shell, suggesting that a large amount of the

mantle A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that. Mantle may refer to: *Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear **Mantle (vesture), an Eastern Orthodox ve ...

and foot were exposed and covered the outside of the shell, as in the extant Cypraeidae and Naticidae.

Possible life habits

These animals were probably quick moving (for gastropods), relying on speed to avoid predators and, when this was not possible, withdrawing deeply into the shell.

Range of distribution

The genus occurs worldwide, and is known from the Silurian to the Early

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

periods.

Discussion of the taxonomy

Although usually classified as a primitive gastropod, there is a minority view that the Bellerophontida actually represented a more primitive, untorted type of mollusk, (see

Torsion Torsion may refer to: Science * Torsion (mechanics), the twisting of an object due to an applied torque * Torsion of spacetime, the field used in Einstein–Cartan theory and ** Alternatives to general relativity * Torsion angle, in chemistry Bi ...

) which evolved a spiral shell independently. Another view is that some Bellerophontids, including ''Bellerophon'', were torted gastropods, but that others were untorted forms.Wagner P. J. 2001. ''Gastropod phylogenetics: progress, problems and implications''. Journal of Paleontology 75: 1128 - 1140. page 1130.

Species

Species within the genus ''Bellerophon'' include: subgenus ''Bellerophon'' * '' Bellerophon needlensis'' - from Late Mississippian from UtahGordon, Mackenzie, Jr. & Yochelson, Ellis L. 1987
''Late Mississippian gastropods of the Chainman Shale, west-central Utah''
112 pp. * '' Bellerophon welshi'' - from Late Mississippian from Utah subgenus ? * '' Bellerophon bicarenus'' Lévillé from early

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carboniferous ...

* '' Bellerophon graphicus''

Moore Moore may refer to: People * Moore (surname) ** List of people with surname Moore * Moore Crosthwaite (1907–1989), a British diplomat and ambassador * Moore Disney (1765–1846), a senior officer in the British Army * Moore Powell (died c. 1 ...

from the late Pennsylvanian ( Virgilian) of Kansas * '' Bellerophon regularis'' ( Waagen) from the Permian of India * '' Bellerophon vasulites'' Montfort - the type species, from the Middle Devonian of Germany * and others

References

* P. D. de Montfort. 1808. Conchyliologie systématique, et classification méthodique des coquilles; offfrant leurs figures, leur arrangement générique, leurs descriptions caractéristiques, leurs noms; ainsi que leur synonymie en plusieurs langues. Coquilles univalves, cloisonnées 1

External links

Bellerophontida
- Palaeos {{Taxonbar, from=Q310262 Prehistoric molluscs of Europe Bellerophontidae Silurian molluscs Devonian molluscs Carboniferous molluscs Permian molluscs Triassic molluscs Early Triassic extinctions Silurian first appearances Late Devonian animals Prehistoric molluscs of North America Jeffersonville Limestone Paleozoic life of Ontario Paleozoic life of Alberta Paleozoic life of Manitoba Paleozoic life of the Northwest Territories Paleozoic life of Quebec