Nannotax3 - ntax_cenozoic - Heliolithus Nannotax3 - ntax_cenozoic - Heliolithus


Classification: ntax_cenozoic -> Discoasterales -> Heliolithaceae -> Heliolithus
Sister taxa: Bomolithus, Heliolithus

Daughter taxa (time control age-window is: 0-800Ma)
both cycles low
Heliolithus kleinpellii
Large, heliolith with two low birefringent cycles. The narrow cycle is around 3/4 the width of the wider cycle.
Heliolithus bukryi
Heliolith with two low birefringent cycles: The narrow cycle is around 1/3 the width of the wider cycle.
one cycle high
Heliolithus cantabriae
Heliolith with a broad, low cycle and a higher, narrower cycle. The narrower cycle is over 3/4 the width of the wider cycle.
Heliolithus knoxii
Heliolith a broad, thin cycle and a higher, narrower cycle. The narrower cycle is about 1/2 the width of the wider cycle.
both cycles high
Heliolithus riedelii
Heliolith with two high cycles, the narrower cycle is around 2/3 the width of the broader.
Heliolithus aktasii
Two relatively high cycles of similar diameter.
Heliolithus sp.
Specimens which cannot be assigned to any established species


Citation: Heliolithus Bramlette and Sullivan, 1961
Rank: Genus
Type species: Heliolithus riedelii Bramlette & Sullivan, 1961

Distinguishing features:
Parent taxon (Heliolithaceae): Discoidal discoasteralids with several distinct cycles including at least one that is birefringent.
This taxon: Discoidal discoasteralids formed of two superposed birefringent cycles.

Farinacci & Howe catalog pages: Heliolithus * , Heliotrochus *


The nanoltihs are formed of two prominent superposed cycles, both of which are strongly birefringent in plan view - the disk and column. The disk is broader than the column, when viewed from the disk side the nannolith appears unicyclic and the elements show anticlockwise obliquity. When viewed from the column side both cycles are visible, the column typically has a vertical edge and does not show imbrication, both cycles show clockwise obliquity.

In well preserved specimens/with favourable orientation a third cycle is visble between these two in at least some species (notably H. cantabriae), in the EM this cycle is visible at the base of the column.

Romein (1979) used crystallographic orientation to infer origin from Fasciculithus bitectus (= Lithoptychius s.l.) and suggested that the disk was distal.

Search data:
LITHS: nannolith-radiate, circular, star-shaped, CROSS-POLARS: V-prominent, R-prominent,
Lith size: 6->18µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): in upper part of Thanetian Stage (70% up, 56.9Ma, in Thanetian 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:


Aubry, M. -P. (2014). Cenozoic Coccolithophores: Discoasterales. Micropaleontology Press, American Museum of Natural History, New York. 1-400. gs

Bramlette, M. N. & Sullivan, F. R. (1961). Coccolithophorids and related nannoplankton of the Early Tertiary in California. Micropaleontology. 7(2): 129-188. gs

Perch-Nielsen, K. (1985). Cenozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 427-555. gs

Romein, A. J. T. (1979). Lineages in Early Paleogene calcareous nannoplankton. Utrecht Micropaleontological Bulletin. 22: 1-231. gs O


Heliolithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 26-3-2023

Taxon Search:
Advanced Search
AphiaID: 601692 Nomenclatural data on WoRMS
Short stables page link: Go to to create a permanent copy of this page - citation notes

Comments (0)

No comments yet on this page. Please do add comments if you spot any problems, or have information to share

Add Comment

* Required information
Captcha Image
Powered by Commentics