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Ceratomya
Classification
Phylum:
Mollusca
Class:
Bivalvia
Subclass:
Anomalodesmata
Order:
Pholadomyoida
Superfamily:
Pholadomyacea
Family:
Ceratomyidae
Formal Genus Name and Reference:
Ceratomya SANDBERGER, 1864, p. 16 [nom. subst. pro Ceromya Agassiz, 1842] [non Ceromya Robineau-Desvoidy, 1830)]
Type Species:
Isocardia excentrica ROEMER, 1836, p. 106, ICZN pend.
Images
(Click to enlarge in a new window)
Fig. F18,1a. * C. excentrica (Roemer), U.Jur.(L. Kimmeridg.), France, LV ext., X1 (549), -- Fig. F18,1b-d. C. aalensis (Quenstedt), M.Jur. (Bajoc.), France, *, LV int., RV int., and int. mold showing pallial line and adductor scars, all X0.7 (Benecke, 1905), -- Fig. F18,1e. C. petricosa (Simpson), L.Jur.(M.Lias.), Eng., LV ext. of a smooth species, X1.3 (Cox, n), -- Fig. F18,1f. C. bajociana (d'Orbigny), M.Jur.(Bajoc.), Eng., transv. sec. through hinge region short distance behind beaks, LV and RV as oriented, former position of ligament dotted, X2 (Cox, n )
Synonyms
Ceromia
Geographic Distribution
L.Jur.-U.Jur., cosmop.
Age Range
Beginning Stage in Treatise Usage:
L.Jur.
Beginning International Stage:
Hettangian
Fraction Up In Beginning Stage:
0
Beginning Date:
201.36
Ending Stage in Treatise Usage:
U.Jur.
Ending International Stage:
Tithonian
Fraction Up In Ending Stage:
100
Ending Date:
143.1
Description
Medium-sized to large, ovate, gibbose, especially anteriorly, with strongly prosogyrous and in some species incoiled, more or less anteriorly placed beaks, some specimens slightly inequivalve, with umbo of either valve extending more anteriorly than that of other, no gape of valve margins, posterodorsal margin of RV with thin outer flange separated from subinternal thickening by groove in which ligament was inserted, corresponding groove on upper (outer) side of reflected margin serving same purpose in LV; anterodorsal margin of RV much thickened below beak in some species; ad- ductor scars small; pallial line bending up sharply posteriorly, shallowly sinuate in some species; sur- face smooth or (more commonly) with concentric or oblique undulations.
References
Museum or Author Information
Classification
Phylum:
Mollusca
Class:
Bivalvia
Subclass:
Anomalodesmata
Order:
Pholadomyoida
Superfamily:
Pholadomyacea
Family:
Ceratomyidae
Formal Genus Name and Reference:
Ceratomya SANDBERGER, 1864, p. 16 [nom. subst. pro Ceromya Agassiz, 1842] [non Ceromya Robineau-Desvoidy, 1830)]
Type Species:
Isocardia excentrica ROEMER, 1836, p. 106, ICZN pend.
Images
(Click to enlarge in a new window)
Fig. F18,1a. * C. excentrica (Roemer), U.Jur.(L. Kimmeridg.), France, LV ext., X1 (549), -- Fig. F18,1b-d. C. aalensis (Quenstedt), M.Jur. (Bajoc.), France, *, LV int., RV int., and int. mold showing pallial line and adductor scars, all X0.7 (Benecke, 1905), -- Fig. F18,1e. C. petricosa (Simpson), L.Jur.(M.Lias.), Eng., LV ext. of a smooth species, X1.3 (Cox, n), -- Fig. F18,1f. C. bajociana (d'Orbigny), M.Jur.(Bajoc.), Eng., transv. sec. through hinge region short distance behind beaks, LV and RV as oriented, former position of ligament dotted, X2 (Cox, n )
Synonyms
Ceromia
Geographic Distribution
L.Jur.-U.Jur., cosmop.
Age Range
Beginning Stage in Treatise Usage:
L.Jur.
Beginning International Stage:
Hettangian
Fraction Up In Beginning Stage:
0
Beginning Date:
201.36
Ending Stage in Treatise Usage:
U.Jur.
Ending International Stage:
Tithonian
Fraction Up In Ending Stage:
100
Ending Date:
143.1
Description
Medium-sized to large, ovate, gibbose, especially anteriorly, with strongly prosogyrous and in some species incoiled, more or less anteriorly placed beaks, some specimens slightly inequivalve, with umbo of either valve extending more anteriorly than that of other, no gape of valve margins, posterodorsal margin of RV with thin outer flange separated from subinternal thickening by groove in which ligament was inserted, corresponding groove on upper (outer) side of reflected margin serving same purpose in LV; anterodorsal margin of RV much thickened below beak in some species; ad- ductor scars small; pallial line bending up sharply posteriorly, shallowly sinuate in some species; sur- face smooth or (more commonly) with concentric or oblique undulations.