Early Miocene (3)
Discoaster (12)
Sphenolithus (20)
Helicosphaera (14)
Description: Helicosphaera with relatively wide central area spanned by a broad tranverse to slightly-oblique disjunct bar and a flange that ends in a spur.
Remarks:
Range: NP17 to NP21.
Neogene: Helicosphaera
Paleogene: Helicosphaera wilcoxonii