Distinguishing features:
Parent taxon (Holococcoliths): Coccoliths formed of minute (ca 0.1µm) rhombohedral micro-crystals. Often a life-cycle stage with heterococcolith counterpart(s).
This taxon: Less common genera
Daughter taxa (time control age-window is: 0-800Ma) | Granddaughter taxa | ||||
Disk-shaped holococcoliths | |||||
Bifidalithus Holococcoliths formed from two blocks divided by a transverse suture. | |||||
Bilapillus Holococcolith with narrow rim and two blocks in central area | |||||
Multipartis Holococcoliths formed from ~7 triangular blocks with irregular blocks in the central-area. | |||||
Munarinus Holococcoliths formed from 4-12 blocks with central-area filled or spanned by disjunct bar or block. | |||||
Octolithus Holococcolith formed of 8 blocks, typically 4 large and 4 small. | |||||
Okkolithus Elliptical holococcolith with broad rim of numerous small blocks and central area of two or more blocks | |||||
Ottavianus Elliptical holococcolith with rim of multiple small elements, central are open except for bridge across short axis. | |||||
Pharus Elliptical coccolith formed of a single block, with two perforations | |||||
Ramsaya Holococcoliths with rim of 12-14 blocks and central-area spanned by a narrow, dark bar. | |||||
Russellia Holococcoliths with rim of 10-26 blocks and a small central block. | |||||
Saepiovirgata Holococcoliths with rim formed from 8-12 elements, and 2 longitudinally-oriented elongate blocks in the central-area. | |||||
Other forms - mostly cavate | |||||
Acuturris Holococcoliths with a proximal plate of three blocks and tall, tapering spines. | |||||
Anfractus Elliptical, cavate (and usually septate) holococcoliths, often bearing hollow spines. Distal surfaces may be perforate and there may be internal buttresses. | |||||
Duocameratus Cavate holococcolith with central septum | |||||
Lacunolithus-Bown | |||||
Metadoga Cavate, conical-flask shaped holococcolith with lid and internal partition. | |||||
Nicholasia Conical shaped holococcolith, usually seen in side view, base weak or absent | |||||
Paulpearsonia Cavate holococcoliths with thin rims and small spines; whole holococcolith behaves as a single crystal in xpl, | |||||
Petrobrasiella Domed-shaped holococcoliths with holes or cavities. | |||||
Pseudoconus Solid, truncated-cone-shaped nannolith with rectangular cross-section constructed from minute, roughly equidimensional crystallites. Possibly a holococcolith. | |||||
Semihololithus Holococcoliths usually seen in side view and comprising a thick proximal plate and spine or process, typically with a cavity or axial canal. | |||||
Stereorhabdus Holoccolith with elliptical base and five-rayed process | |||||
Tanzanella Cavate holococcolith with internal walls and distal protrusions | |||||
Thecatus Cavate holococcolith with box-shape, high rim and thin proximal plate, short spine on distal surface | |||||
unidentified holococcoliths |
Taxonomy:
Farinacci & Howe catalog pages:
Distinguishing features:
Parent taxon (Holococcoliths): Coccoliths formed of minute (ca 0.1µm) rhombohedral micro-crystals. Often a life-cycle stage with heterococcolith counterpart(s).
This taxon: Less common genera
Search data:
: holococcolith, |
Lith size: 0->0µm; |
Geological Range:
Last occurrence (top): at top of Paleocene Epoch (100% up, 56Ma, in Thanetian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within Toarcian Stage (174.70-184.20Ma, base in Toarcian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Rarer genera compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 9-10-2024
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10985 Go to Archive.is to create a permanent copy of this page - citation notes |
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