Suborder:
|
Tornoceratina
|
Superfamily:
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Tornoceratoidea
|
Family:
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Tornoceratidae
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Subfamily:
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Tornoceratinae
|
Genus:
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Tornoceras
|
Species:
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concentricum |
Qualifier:
|
ss |
Author:
|
House 1965,p.113
|
Lower Boundary:
|
UD2A--UD2B:(verneuili Zone base) [07,75], 374 million years
|
Upper Boundary:
|
UD2F--UD2G:(subvaricatum Zone base), 370.8 million years
|