Nannotax3 - ntax_cenozoic - Heliolithaceae


Classification: ntax_cenozoic -> Discoasterales -> Heliolithaceae
Sister taxa: Discoasteraceae, Fasciculithaceae, Heliolithaceae, Sphenolithaceae

Daughter taxa (time control age-window is: 0-800Ma)Granddaughter taxa
Discoidal discoasteralids with a wide non-birefringent cycle and at least one narrower birefringent cycle, i.e., narrower than the diameter of the nannolith.
B. aquilus
B. bramlettei
B. conicus
B. elegans
B. megastypus
B. supremus
B. sp.

Discoidal discoasteralids with birefringent appearance.
H. aktasii
H. bukryi
H. cantabriae
H. kleinpellii
H. knoxii
H. riedelii
H. sp.


Citation: Heliolithaceae Hay & Mohler, 1967
Rank: Family

Taxonomic discussion:
Group of nannoliths closely allied to the discoasters, and probably transitional between typically VR heterococcolith morphology and the more derived, single crystal-unit form of Discoaster.

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]

Search data:
MetricsLith size: 5->18┬Ám;
The morphological data given here can be used on the advanced search page. See also these notes

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. gs


Heliolithaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 28-9-2021

Taxon Search:
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Short stable page link: Go to to create a permanent copy of this page - citation notes

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