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Olcostephanus
Classification
Phylum:
Mollusca
Class:
Cephalopoda
Order:
Ammonitida
Superfamily:
Perisphinctaceae
Family:
Olcostephanidae
Formal Genus Name and Reference:
Olcostephanus NEUMAYR, 1875b, p. 922
Type Species:
Ammonites astierianus ORBIGNY, 1840, p. 115, OD
Images
(Click to enlarge in a new window)
FIG. 32a,b. *O. (O.) astierianus (O RBIGNY ), Upper Valanginian, France; lectotype, macroconch, ×0.75 (Cooper, 1981).——F IG . 32c,d. O. (O.) atherstoni (SHARPE), Upper Valanginian, Germany; microconch, ×0.75 (Neumayr & Uhlig, 1881).—FIG. 32e,f. O. (O.) sulcosus PAVLOW, Lower Hauterivian, England; holotype, × 1 (Pavlow, 1892).——FIG. 32g,h. O. (O.) rogersi (KITCHIN), Upper Valanginian, southern Africa; holotype, macroconch, × 0.5 (Kitchin, 1908). ——F IG . 32i. O. (O.) madagascariensis LEMOINE , Upper Valanginian, Madagascar; holotype, ×0.75 (Collignon, 1962a).
Synonyms
Holcostephanus, Astieria
Geographic Distribution
Europe, southern Africa, eastern Africa, Madagascar, Pakistan, Mexico, Colombia, Peru
Age Range
Beginning Stage in Treatise Usage:
Lower Cretaceous (Lower Valanginian)
Beginning International Stage:
Valanginian
Fraction Up In Beginning Stage:
0
Beginning Date:
137.7
Ending Stage in Treatise Usage:
Lower Cretaceous (Lower Hauterivian)
Ending International Stage:
Hauterivian
Fraction Up In Ending Stage:
45
Ending Date:
129.86
Description
Rather evolute to rather involute, compressed to globose or cadicone, with well-rounded venter, short primary ribs on umbilical wall, with or without umbilical bullae or spines, giving rise to 2 or more straight or slightly curved, radial, rursi- or prorsiradiate secondary ribs, additional secondary ribs may be intercalated, secondary ribs may, rarely, branch but are never virgatotome, marked constrictions with collared ribs, oblique to other ribs, present in early stages of macroconchs or throughout. Macroconchs with simple, collared apertures, microconchs with short to long, spatulate lappets.
References
Museum or Author Information
Classification
Phylum:
Mollusca
Class:
Cephalopoda
Order:
Ammonitida
Superfamily:
Perisphinctaceae
Family:
Olcostephanidae
Formal Genus Name and Reference:
Olcostephanus NEUMAYR, 1875b, p. 922
Type Species:
Ammonites astierianus ORBIGNY, 1840, p. 115, OD
Images
(Click to enlarge in a new window)
FIG. 32a,b. *O. (O.) astierianus (O RBIGNY ), Upper Valanginian, France; lectotype, macroconch, ×0.75 (Cooper, 1981).——F IG . 32c,d. O. (O.) atherstoni (SHARPE), Upper Valanginian, Germany; microconch, ×0.75 (Neumayr & Uhlig, 1881).—FIG. 32e,f. O. (O.) sulcosus PAVLOW, Lower Hauterivian, England; holotype, × 1 (Pavlow, 1892).——FIG. 32g,h. O. (O.) rogersi (KITCHIN), Upper Valanginian, southern Africa; holotype, macroconch, × 0.5 (Kitchin, 1908). ——F IG . 32i. O. (O.) madagascariensis LEMOINE , Upper Valanginian, Madagascar; holotype, ×0.75 (Collignon, 1962a).
Synonyms
Holcostephanus, Astieria
Geographic Distribution
Europe, southern Africa, eastern Africa, Madagascar, Pakistan, Mexico, Colombia, Peru
Age Range
Beginning Stage in Treatise Usage:
Lower Cretaceous (Lower Valanginian)
Beginning International Stage:
Valanginian
Fraction Up In Beginning Stage:
0
Beginning Date:
137.7
Ending Stage in Treatise Usage:
Lower Cretaceous (Lower Hauterivian)
Ending International Stage:
Hauterivian
Fraction Up In Ending Stage:
45
Ending Date:
129.86
Description
Rather evolute to rather involute, compressed to globose or cadicone, with well-rounded venter, short primary ribs on umbilical wall, with or without umbilical bullae or spines, giving rise to 2 or more straight or slightly curved, radial, rursi- or prorsiradiate secondary ribs, additional secondary ribs may be intercalated, secondary ribs may, rarely, branch but are never virgatotome, marked constrictions with collared ribs, oblique to other ribs, present in early stages of macroconchs or throughout. Macroconchs with simple, collared apertures, microconchs with short to long, spatulate lappets.