Suborder:
|
Goniatitina
|
Superfamily:
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Dimorphoceratoidea
|
Family:
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Girtyoceratidae
|
Subfamily:
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Girtyoceratinae
|
Genus:
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Eumorphoceras
|
Species:
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yatesae |
Qualifier:
|
ss |
Author:
|
Trevin 1970,p.40
|
Lower Boundary:
|
GBY E2a2--E2a3 (Eu.bisulcatum--yatesae), 323 million years
|
Upper Boundary:
|
GBY E2a3--E2b1(Eu.yatesae--Cr.edalensis), 322.5 million years
|