Families and genera incertae sedis
Coccolithophore families - both these families have unusual coccolith structure and no obvious structural affinities to other coccolithopohre groups. They have extant members so their affinites will probably be determined by molecular genetics in the reasonably near term.
The following genera are a mixed group of living and fossil coccolithophores or nannoliths of uncertain affinity.
Neogene: Incertae sedis