Order Stephanodiscales Nikolaev and Harwood
Mediophyceae - Stephanodiscales - Thalassiosirophycidae
Parent taxon: Thalassiosirophycidae according to M. D. Guiry and G. M. Guiry 2017
Sister taxa: none
Subtaxa: Stephanodiscaceae
Distribution:
• Quaternary of India (2 collections), North Atlantic (1), Sweden (1), United States (8: California, Oregon)
• Blancan of United States (1: California)
• Pliocene to Pleistocene of Ethiopia (2)
• Pliocene of Armenia (1), Japan (2), United States (1: Oregon)
• Miocene of United States (1: North Carolina)
• Eocene to Miocene of Argentina (1)
Total: 21 collections including 37 occurrences