Bellerophontidae

Bellerophontidae
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Order:	Bellerophontida
Family:	Bellerophontidae McCoy, 1851
Subfamilies and Genera
Subfamily Bellerophontinae: Bellerophon Aglaoglypta Liljevallospira Pharkidonotus Prosoptychus Ptychobellerophon Ptychosphaera Subfamily Bucaniinae Subfamily Bucanopsinae Subfamily Carinaropsinae Subfamily Knightitinae Subfamily Plectonotinae Subfamily Pterothecinae Subfamily Salpingostomatinae Subfamily Undulabucaniinae

The Bellerophontidae are an extinct family of globose and specialised bellerophonts. These are fossil mollusks with coiled shells, and they are thought to have been gastropods.

Geological range

These mollusks appeared during the Ordovician period and continued through to the Triassic period.

Shell description

The shell resembles a miniature Nautilus, with greatly overlapping, rounded whorls, in which the last whorl completely encompasses the others, leaving either a very narrow umbilicus on either side, or none at all. At the aperture 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 it is possible that these were active, fast-moving molluscs.

Taxonomy

Knight et al 1960 in the Treatise on Invertebrate Paleontology consider the Bellerophontidae a very large family made up of a number of subfamilies and tribes. The classification presented is as follows:

• 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 1938
• Subfamily Bellerophontinae McCoy 1851
• Subfamily Knightitinae Knight 1956

Recently Peter Wagner has presented cladograms which divide this assemblage into a number of different groups, as well as combining the Bellerophontidae with the family Sinuitidae.

References

• Knight, J. B., Cox, L. R., Keen, A. M., Batten, R. L., Yochelson, E. L., and Robertson, R. (1960). Systematic descriptions [Archaeogastropoda]. In Moore, R. C. (ed.) Treatise on Invertebrate Paleontology. Part I. Mollusca 1, Geological Society of America and Kansas University Press, Colorado and Kansas.
• Linsley, R. M. 1978. Locomotion rates and shell form in the gastropoda. Malacologia 17, 193-206
• Moore, R.C., Lalicker, C.G., and Fischer, A. G., (1952), Invertebrate Fossils, McGraw Hill Book Company, New York; 766 pp.
• Wagner, P. J. (2001) Gastropod phylogenetics: progress, problems and implications. Journal of Paleontology 75: 1128 - 1140
• ----- [no date]. Systematic Paleontology of the Earliest Gastropods (Including Family and Genus Level Stratigraphic Ranges and Synonyms

External links

• Bellerophontida - Palaeos