†''Orthonychiidae'' is an extinct

taxonomic 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme of classes (a taxonomy) and the allocation ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

s, marine,

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

s in the clade

Cyrtoneritimorpha Cyrtoneritimorpha, also Cyrtoneritida, is a clade of fossil sea snails, marine gastropod mollusks within the clade Neritimorpha Neritimorpha is a clade of gastropod molluscs that contains around 2,000 extant species of sea snails, limpets, fr ...

. There is an unusually great degree of variability within the shells of species in the genus ''Orthonychia'', but an analysis of this variability has not been done yet (2008).

Genera

Genus ''Orthonychia'' Hall, 1843 *''Orthonychia acuta'' Roemer, 1856 *''Orthonychia baldwini'' Rohr et al., 1981 *''Orthonychia belli'' Clarke, 1908 *''Orthonychia bowsheri'' Yochelson, 1956 *''Orthonychia chesterense'' Meek & Worthen, 1866 *''Orthonychia concavum'' Hall, 1860 *''Orthonychia conicum'' Hall, 1860 *''Orthonychia conoidea'' (Goldfuss, 1844) *''Orthonychia cornuforme'' (Winchell, 1863) *''Orthonychia costata'' (Barrois, 1889) *''Orthonychia daschi'' (Rohr & Smith, 1978) *''Orthonychia dentalium'' Hall, 1862 *''Orthonychia enorme'' (Lindström, 1884) *''Orthonychia infabricatus'' Hyde, 1953 *''Orthonychia marblecreekensis'' Talent & Philip, 1956 *''Orthonychia obliquesulata'' Spitz, 1907 *''Orthonychia pajerensis'' Chronic, 1949 *''Orthonychia parva'' (Shumard & Swallow, 1858) *''Orthonychia parvulum'' Whiteaves, 1892 *''Orthonychia pentalvea'' Talent & Philip, 1956 *''Orthonychia perplexum'' (Hall, 1879) *''Orthonychia prosseri'' Clarke & Swartz, 1913 *''Orthonychia protei'' (Oehlert, 1883) *''Orthonychia puellaris'' (Whidborne, 1891) *''Orthonychia quadrangularis'' (Whidborne, 1891) *''Orthonychia rostratus'' (Trenkner, 1867) *''Orthonychia sciotoensis'' Hyde, 1953 *''Orthonychia sileni'' (Oehlert, 1883) *''Orthonychia subrectum'' Hall, 1860 - type species *''Orthonychia steinbergensis'' Kegel, 1926 *''Orthonychia talon'' Tolmachoff, 1930 *''Orthonychia tortuosa'' (Hall, 1860) *''Orthonychia trirotundolobatum'' (Talent & Philip, 1956) *''Orthonychia unguiculata'' Clarke & Swartz, 1913 *''Orthonychia variablis'' Tyler, 1965 *''Orthonychia vishtytica'' Saladzius, 1966 *''Orthonychia vomerium'' (Winchell, 1863) *''Orthonychia waverlyensis'' Hyde, 1953 * ''Orthonychia compressa'' / ''Platyceras'' (''Orthonychia'') ''compressum'' Girty 1910 * ''Orthonychia ungula'' / ''Platyceras'' (''Orthonychia'') ''ungula'' (Weller, 1906)"†''Platyceras'' (''Orthonychia'') ''ungula'' Weller 1906 (snail)"

Paleobiology Database The Paleobiology Database (PBDB) is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database originated in the NCEAS-funded Phanerozoic Marine Pale ...

, accessed 8 August 2010.

References

{{Neritimorpha-stub