Daughter taxa (time control age-window is: 0-800Ma)![]() | Granddaughter taxa | ||||
Bomolithus Discoidal discoasteralids with a wide non-birefringent cycle and at least one narrower birefringent cycle, i.e., narrower than the diameter of the nannolith. | |||||
![]() | ![]() | ![]() | ![]() | Heliolithus Discoidal discoasteralids formed of two superposed birefringent cycles. |
Taxonomy:
Distinguishing features:
Parent taxon (Discoasterales): Radially symmetrical nannoliths formed from one to several separate cycles of elements that radiate from a common centre or axis.
This taxon: Discoidal discoasteralids with several distinct cycles including at least one that is birefringent.
Farinacci & Howe catalog pages: Heliolithaceae [no catalog entry yet]
Morphology:
Size:
Tags | LITHS: |
Metrics | Lith size: 5->18µm; |
Geological Range:
Last occurrence (top): at base of Ypresian Stage (1% up, 55.9Ma, in Ypresian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Selandian Stage (4% up, 61.5Ma, in Selandian stage). Data source: Total of range of species in this database
Plot of occurrence data:
Hay, W. W. & Mohler, H. P. (1967). Calcareous nannoplankton from Early Tertiary rocks at Point Labau, France and Paleocene-Early Eocene correlations. Journal of Paleontology. 41(6): 1505-1541. gsReferences:
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Heliolithaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 3-7-2022
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=697 Go to Archive.is to create a permanent copy of this page - citation notes |
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