The Bellerophontidae are an extinct family of specialized globose bellerophontids, Paleozoic and early Triassic mollusks of the class Gastropoda.
Geological range These mollusks appeared in the Late Cambrian and continued until the Early Triassic.
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 these possibly were active, fast-moving molluscs.
Taxonomy
1960 taxonomy Knight et al. 1960 in the Treatise on Invertebrate PaleontologyKnight J. B., Cox L. R., Keen A. M., Batten R. L., Yochelson E. L., & 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. 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 & 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, 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 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 monoplacophorans 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 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
Further reading 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. ----- [no date]. Systematic Paleontology of the Earliest Gastropods (Including Family and Genus Level Stratigraphic Ranges and Synonyms
External links
Bellerophontida - Palaeos
pl:Belerofony