Suborder:
|
Goniatitina
|
Superfamily:
|
Pericycloidea
|
Family:
|
Muensteroceratidae
|
Genus:
|
Akeshakeceras
|
Species:
|
longilobatum+ |
Qualifier:
|
sn |
Author:
|
Liang & Wang 1991,p.81
|
Lower Boundary:
|
RUN Kos'vinskii gorizont base, 349 million years
|
Upper Boundary:
|
RUN Nortnichskiy gorizont top, 339 million years
|