Suborder:
|
Goniatitina
|
Superfamily:
|
Pericycloidea
|
Family:
|
Muensteroceratidae
|
Genus:
|
Akeshakeceras |
Qualifier:
|
gn |
Author:
|
Liang & Wang 1991,p.80
|
Lower Boundary:
|
RUN Kos'vinskii gorizont base, 349 million years
|
Upper Boundary:
|
RUN Nortnichskiy gorizont top, 339 million years
|