Suborder:
|
Goniatitina
|
Superfamily:
|
Dimorphoceratoidea
|
Family:
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Anthracoceratidae
|
Genus:
|
Anthracoceras
|
Species:
|
tenuispirale |
Qualifier:
|
ss |
Author:
|
Demanet 1941,p.148
|
Lower Boundary:
|
GBY E2b1--E2b2 (Cr.edalensis--holmesi), 322 million years
|
Upper Boundary:
|
GBY E2b2--E2b3 (holmesi--Cr.nititoides), 321.5 million years
|