Suborder:
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Goniatitina
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Superfamily:
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Dimorphoceratoidea
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Family:
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Dimorphoceratidae
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Subfamily:
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Dimorphoceratinae
|
Genus:
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Trizonoceras
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Species:
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berkhense |
Qualifier:
|
ss |
Author:
|
Kuzina & Yatskov 1988,p.31
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Lower Boundary:
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RUS Nm1a1 base, Hypergon.-Ferganoc. GZ, 327.8 million years
|
Upper Boundary:
|
RUS Nm1a2--Nm1b1,Uralopron.-Cravenoc. GZ, 326.4 million years
|