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