Suborder:
|
Goniatitina
|
Superfamily:
|
Pericycloidea
|
Family:
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Maxigoniatitidae
|
Genus:
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Beyrichoceras
|
Species:
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tardum |
Qualifier:
|
ss |
Author:
|
Ruzhencev 1966,p.53
|
Lower Boundary:
|
Up.Visean Goniatites BZ base [up.VIS], 333.5 million years
|
Upper Boundary:
|
DER Go beta striatus--Go beta falcatus, 329.4 million years
|