Suborder:
|
Goniatitina
|
Superfamily:
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Gastrioceratoidea
|
Family:
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Gastrioceratidae
|
Genus:
|
Gastrioceras
|
Species:
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formosum |
Qualifier:
|
ss |
Author:
|
McCaleb 1963,p.877
|
Lower Boundary:
|
UAR Winslow Fm. base, 310.2 million years
|
Upper Boundary:
|
UAR Winslow Fm.--low. Atoka Fm., 309.5 million years
|