The Bellerophontidae are an extinct

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

of specialized globose bellerophontids, Paleozoic and early Triassic

mollusks Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

of the class

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. ...

Geological range

These mollusks appeared in the Late

Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...

and continued until 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 ...

Shell description

The shell resembles a miniature ''

Nautilus The nautilus (, ) is a pelagic marine mollusc of the cephalopod family Nautilidae. The nautilus is the sole extant family of the superfamily Nautilaceae and of its smaller but near equal suborder, Nautilina. It comprises six living species in t ...

'', with greatly overlapping, rounded

whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

, in which the

last whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

completely encompasses the others, leaving either a very narrow umbilicus on either side, or none at all. At the

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

of the shell is a slit, which results in a sort of low ridge that runs along the length of shell. The shell has a low profile and these possibly were active, fast-moving molluscs.

Taxonomy

1960 taxonomy

Knight ''et al.'' 1960 in the ''

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and co ...

'' consider the Bellerophontidae a very large family made up of a number of subfamilies and tribes. The 1960 classification places the family Bellerophontidae in the order Bellerophontida

Ulrich Ulrich (), is a German given name, derived from Old High German ''Uodalrich'', ''Odalric''. It is composed of the elements '' uodal-'' meaning "(noble) heritage" and ''-rich'' meaning "rich, powerful". Attested from the 8th century as the name of Al ...

& Scofield, 1897. The classification presented is: Order Bellerophontida Ulrich & Scofield, 1897 * Family Bellerophontidae McCoy, 1851 ** Subfamily Tropidodiscinae Knight, 1956 ** Subfamily Bucaniinae Ulrich & Scofield, 1897 :** Tribe Bucaniides Ulrich & Scofield, 1897 :** Tribe Salpingostomatides Koken, 1925 ** Subfamily Carinaropsinae Ulrich & Scofield, 1897 ** Subfamily Pterothecinae

Wenz Wenz may refer to: Broadcasting *WENZ, a radio station (107.9 FM) licensed to Cleveland, Ohio, United States People *Alfred Wenz (1919–1944), a German soldier *Fred Wenz aka Frederick Charles Wenz (born 1941), a baseball player *Peter Wenz (born ...

, 1938 ** Subfamily Bellerophontinae McCoy, 1851 ** Subfamily Knightitinae Knight, 1956

2001 taxonomy

Recently, Peter J. Wagner presented cladograms which divide this assemblage into a number of different groups, as well as combining the Bellerophontidae with the family Sinuitidae. Wagner P. J. 2001. ''Gastropod phylogenetics: progress, problems and implications''. Journal of Paleontology 75: 1128-1140. while Bouchet & Rocroi (2005) places Sinuitidae as a family in superfamily Bellerophontoidea.

2005 taxonomy

The taxonomy of the Gastropoda by Bouchet & Rocroi, 2005Bouchet P. & Rocroi J.-P. (Ed.); Frýda J., Hausdorf B., Ponder W., Valdes A. & Warén A. 2005. ''Classification and nomenclator of gastropod families''. Malacologia: International Journal of Malacology, 47(1-2). ConchBooks: Hackenheim, Germany. . ISSN 0076-2997. 397 pp. http://www.vliz.be/Vmdcdata/imis2/ref.php?refid=78278 categorizes Bellerophontidae like this: * Paleozoic molluscs of uncertain systematic position ** Paleozoic molluscs with isostrophically coiled shells of uncertain position within Mollusca (Gastropoda or Monoplacophora) *** superfamily

Bellerophontoidea Bellerophontoidea, common name "bellerophonts",Bouchet P. & Rocroi J.-P. (Ed.); Frýda J., Hausdorf B., Ponder W., Valdes A. & Warén A. 2005. ''Classification and nomenclator of gastropod families''. Malacologia: International Journal of Malaco ...

McCoy, 1852 - Bellerophontoidea is the only superfamily in this taxon. **** family Bellerophontidae McCoy, 1852 ***** subfamily Bellerophontinae McCoy, 1852 - synonym: Liljevallospiridae Golikov & Starobogatov, 1889 ***** subfamily Bucanopsinae Wahlman, 1992 ***** subfamily Cymbulariinae Horný, 1963 ***** subfamily Knightitinae Knight, 1956 Bouchet & Rocroi, on page 271 (2005), also state that the assignation of "''symmetrical univalved mollusks "bellerophonts" either to Gastropoda or to Monoplacophora or Tergomya is controversial."'' In other words, it is not yet certain whether bellerophonts are in fact real gastropods, they might be

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 ...

ns or they might belong to a group (Tergomya) that is closely related to the gastropods, but not actually gastropods.

Genera

Genera in the family Bellerophontidae include: * subfamily Bellerophontinae ** genus ''

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 ...

'' Montfort, 1808 - type genus of the subfamily Bellerophontinae * subfamily Bucanopsinae ** genus '' Bucanopsis'' Ulrich, 1897 - type genus of the subfamily Bucanopsinae * subfamily Cymbulariinae ** genus '' Cymbularia'' Koken, 1896 - type genus of the subfamily Cymbulariinae * subfamily Knightitinae ** genus '' Knightites'' Moore, 1941 - type genus of the subfamily Knightitinae other genera include: * '' Aglaoglypta'' * '' Liljevallospira'' * '' Pharkidonotus'' * '' Prosoptychus'' * '' Ptychobellerophon'' * '' Ptychosphaera''

References

External links

- Palaeos {{Taxonbar, from=Q4883816 Prehistoric mollusc families Early Triassic extinctions pl:Belerofony