Ammonidium |
Ammonidium uncinum
|
Oklahoma |
Early Devonian |
|
Anomaloplaisium |
Anomaloplaisium lumariacuspis
|
Indiana |
Late Ordovician |
|
Aptea |
Aptea anaphrissa
|
Nd |
Nd |
|
Aptea |
Aptea polymorpha
|
Germany |
Early Cretaceous |
|
Apteodinium |
Apteodinium granulatum
|
Germany |
Early Cretaceous |
|
Apteodinium |
Apteodinium sp
|
Nd |
Nd |
|
Apteodinium |
Apteodinium spiridoides
|
Germany |
Oligocene |
|
Aquadulcum |
Aquadulcum myalupense
|
Nd |
Nd |
|
Archaeosphaeroides |
Archaeosphaeroides barbertonensis
|
South Africa |
|
|
Aremoricanium |
Aremoricanium decoratum
|
Oklahoma |
Middle Ordovician |
|
Aremoricanium |
Aremoricanium rigaudiae
|
Oklahoma |
Middle Ordovician |
|
Aremoricanium |
Aremoricanium simplex
|
Oklahoma |
Middle Ordovician |
|
Aremoricanium |
Aremoricanium squarrosum
|
Indiana |
Late Ordovician |
|
Areoligera |
Areoligera cassiculus
|
Alabama |
Early Eocene |
|
Areosphaeridium |
Areosphaeridium diktyoplokum
|
Germany |
Eocene |
|
Arpylorus |
Arpylorus antiquus
|
Africa |
Late Gothlandian |
|
Ascodinium |
Ascodinium acrophorum
|
Australia |
Middle Cretaceous |
|