Daughter taxa (time control age-window is: 0-800Ma)![]() | |||||
| Semihololithus biskayae Cavate holococcoliths comprising a thick proximal plate and a solid domed distal surface with perforations or pits. | |||||
| Semihololithus dimidius Small holococcolith seen in side view comprising a thin proximal plate and a thin-walled tapering distal process that surrounds a central cavity divided in half by a narrow wall. | |||||
| Semihololithus kanungoi Small to medium sized cavate holococcolith seen in side view comprising a thin proximal plate, thick walls and a thin-walled, hollow distal process/spine that tapers initially then becomes parallel sided. | |||||
| Semihololithus pseudobiskayae Large, blocky, with steep-walled rim and domed upper surface. Only known from LM side view | |||||
| Semihololithus sp. cf. S. biskayae Similar to Semihololithus biskayae but smaller and with a thinner proximal plate and relatively larger central cavity. | |||||
| Semihololithus tentorium Medium-sized holococcolith seen in side view comprising a thin proximal plate, thick walls and a relatively thick-walled rapidly tapering cavate distal process/spine. | |||||
| Naninfula figularia Broadly elliptical coccolith with low tube and high distal cover with four very large openings | |||||
| Naninfula hexaporus Small elliptical holococcolith with domal cover with single cycle of ca 7 large pores | |||||
| Semihololithus sp. Specimens which cannot be assigned to any established species | |||||
| Cretaceous species | |||||
| Semihololithus bicornus | |||||
| Semihololithus priscus | |||||
Distinguishing features:
Parent taxon (fossil holococcoliths): Holococcolith genera only known from the fossil record
This taxon: Paleogene holococcoliths usually seen in side view and comprising a thick proximal plate and spine or process, typically with a cavity or axial canal.
Farinacci & Howe catalog pages:
Semihololithus *
| Lith size: 3->7µm; |
Geological Range:
Last occurrence (top): at top of Late Eocene Sub-Epoch (100% up, 33.9Ma, in Priabonian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within Maastrichtian Stage (66.04-72.17Ma, base in Maastrichtian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Perch-Nielsen, K. (1971b). Einige neue Coccolithen aus dem Paläozän der Bucht von Biskaya und dem Eozän der Labrador See. Bulletin of the Geological Society of Denmark. 21: 347-361. gs References:

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Semihololithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 6-2-2026
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1241 Go to Archive.is to create a permanent copy of this page - citation notes |
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