The following genera of nannoliths are not currently assigned to any family, reflecting the uncertinty in their affinities.
Florisphaera
Minylitha
Citation:
Genera incertae sedis
This is a mixed group of nannofossils that cannot be assigned to either one of the four heterococcolith orders or one of the five nannolith families. It includes:
Heterococcoliths
Family Alisphaeraceae (Alisphaera, Canistrolithus, Polycrater)