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Arnioceras
Classification
Phylum:
Mollusca
Class:
Cephalopoda
Order:
Ammonitida
Superfamily:
Psilocerataceae
Family:
Arietitidae
Formal Genus Name and Reference:
Arnioceras HYATT, 1867
Type Species:
A. cuneiforme (ICZN
Opinion 307)
Images
(Click to enlarge in a new window)
Fig. 266,2. "A. cunei/orme, Fr.; 2ap,
XI (200")
Synonyms
Amioceras, Eparnioceras
Geographic Distribution
Eu.-N.Afr.-Indon.-N.Caled.-S. Alaska-Can.-?Nev.-Mex.-Colombia-Ecuador - Peru- Chil
Age Range
Beginning Stage in Treatise Usage:
Sinem.
Beginning International Stage:
Sinemurian
Fraction Up In Beginning Stage:
0
Beginning Date:
199.46
Ending Stage in Treatise Usage:
Sinem.
Ending International Stage:
Sinemurian
Fraction Up In Ending Stage:
100
Ending Date:
192.9
Description
Evolute, whorl sides slightly divergent; nucleus smooth to variable age, ribs strong, sharp, straight until they near ventro- lateral edge, where they swing forward, then fade on venter.
References
Museum or Author Information
Classification
Phylum:
Mollusca
Class:
Cephalopoda
Order:
Ammonitida
Superfamily:
Psilocerataceae
Family:
Arietitidae
Formal Genus Name and Reference:
Arnioceras HYATT, 1867
Type Species:
A. cuneiforme (ICZN
Opinion 307)
Images
(Click to enlarge in a new window)
Fig. 266,2. "A. cunei/orme, Fr.; 2ap,
XI (200")
Synonyms
Amioceras, Eparnioceras
Geographic Distribution
Eu.-N.Afr.-Indon.-N.Caled.-S. Alaska-Can.-?Nev.-Mex.-Colombia-Ecuador - Peru- Chil
Age Range
Beginning Stage in Treatise Usage:
Sinem.
Beginning International Stage:
Sinemurian
Fraction Up In Beginning Stage:
0
Beginning Date:
199.46
Ending Stage in Treatise Usage:
Sinem.
Ending International Stage:
Sinemurian
Fraction Up In Ending Stage:
100
Ending Date:
192.9
Description
Evolute, whorl sides slightly divergent; nucleus smooth to variable age, ribs strong, sharp, straight until they near ventro- lateral edge, where they swing forward, then fade on venter.