Daughter taxa (time control age-window is: 0-800Ma)![]() | ||||
| Helicosphaera ampliaperta Central-area open; wing merges into flange; blanket confined to central opening | ||||
| Helicosphaera scissura Like H. ampliaperta but with a narow slit-like opening in the central-area. | ||||
| Helicosphaera magnifica Large to medium sized, with closed central-area and wide wing which extends along most of length of helicolith. | ||||
| Helicosphaera alata Like H. magnifica but with open central area, and larger | ||||
Distinguishing features:
Parent taxon (Helicosphaera): Coccoliths with helical flange; arranged spirally on the coccosphere
This taxon: Early Miocene group of Helicosphaera species without a sinlge central opening, blanket confined to central area, variably developed wing.
Farinacci & Howe catalog pages:
| Lith size: 7->15µm; |
Geological Range:
Last occurrence (top): at top of NN5 zone (100% up, 13.5Ma, in Serravallian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within NN2 zone (19.00-22.82Ma, base in Aquitanian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 225-265. gs References:

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H. ampliaperta group compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 11-4-2026
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=635 Go to Archive.is to create a permanent copy of this page - citation notes |
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