Phylum Bryozoa (Ordovician-Recent):
Class Phylactolaemata (Tertiary-Recent): freshwater, 12 genera.
Class Stenolaemata (Ordovician-Recent)
Order Cyclostomata (Ordovician-Recent)
Order Trepostomata (Ordovician-Trias)
Order Cryptostomata (Ordovician-Permian)
Order Fenestrata (Ordovician-Permian)
Order Cystoporata (Ordovician-Permian