TaxNo: 5875Genus Grioceras
| Suborder: |
Goniatitina
|
| Superfamily: |
Cycloloboidea
|
| Family: |
Vidrioceratidae
|
| Genus: | Grioceras |
| Qualifier: | gy |
| Author: |
Tumanskaia 1939,p.18
|
| Valid: | Martoceras Tumanskaya,1938,p.107 [?] |
| Lower Boundary: |
TAP lower Bus-Ter beds base, 270.6 million years
|
| Upper Boundary: |
TAP upper Bus--Ter beds top, 268 million years
|