Suborder:
|
Tornoceratina
|
Superfamily:
|
Dimeroceratoidea
|
Family:
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Cheiloceratidae
|
Genus:
|
Cheiloceras
|
Subgenus:
|
Puncticeras |
Qualifier:
|
ge |
Author:
|
Becker 1993,p.275
|
Lower Boundary:
|
UD2A--UD2B:(verneuili Zone base) [07,75], 374 million years
|
Upper Boundary:
|
UD2F--UD2G:(subvaricatum Zone base), 370.8 million years
|