A silicoflagellate plexus associated with Bachmannocena diodon subsp. nodosa from the Eastern Equatorial Pacific (Ocean Drilling Program Leg 138)

Upper Miocene (~6 Ma) sediments from a north-south transect of Ocean Drilling Program Holes 848B, 849B, 850B, 851B across the equator in Eastern Pacific record an episode unusual skeletal variability associated with silicoflagellate Bachmannocena diodon subsp. nodosa (Bukry) Bukry, 1987. Skeletons this plexus persisted for between 55,000 and 75,000 years include arch 2-sided basal ring, highly morphology genus. Groups morphotypes were common within plexus episode, occur systematic sequence that is consistent sites. As result study, silicoflagellates previously placed genus Neonaviculopsis Locker Martini, 1986 are now considered part of the plexus.