Nannotax3 - ntax_main - Semihololithus Nannotax3 - ntax_main - Semihololithus

Semihololithus


Classification: ntax_main -> Holococcoliths -> fossil holococcoliths -> Semihololithus
Sister taxa: Daktylethra, Holodiscolithus, Lanternithus, Multipartis, Octolithus, Quadrilateris, Semihololithus, Varolia, Youngilithus, Zygrhablithus ⟩⟨ Aubrysphaera, Corannulus, Orthozygus, Peritrachelina, Unidentified fossil holococcoliths

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


Taxonomy:
Citation: Semihololithus Perch-Nielsen, 1971
Taxonomic rank: genus
Type species: Semihololithus biskayae Perch-Nielsen, 1971

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 *

Search data:
Lith size: 3->7µm;
The morphological data given here can be used on the advanced search page. See also these notes

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:

References:

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


nannotaxlogo400px

Semihololithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 6-2-2026

Taxon Search:
Advanced Search

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



Add Comment

* Required information
Captcha Image

Comments

No comments yet. Be the first!