Distinguishing features: Less common genera
|Daughter taxa (time control age-window is: 0-800Ma)||Granddaughter taxa|
Holococcoliths formed from two blocks divided by a transverse suture.
Holococcolith with narrow rim and two blocks in central area
Holococcoliths formed from ~7 triangular blocks with irregular blocks in the central-area.
Holococcoliths formed from 4-12 blocks with central-area filled or spanned by disjunct bar or block.
Holococcolith formed of 8 blocks, typically 4 large and 4 small.
Elliptical holococcolith with broad rim of numerous small blocks and central area of two or more blocks
Elliptical holococcolith with rim of multiple small elements, central are open except for bridge across short axis.
Elliptical coccolith formed of a single block, with two perforations
Holococcoliths with rim of 12-14 blocks and central-area spanned by a narrow, dark bar.
Holococcoliths with rim of 10-26 blocks and a small central block.
Holococcoliths with rim formed from 8-12 elements, and 2 longitudinally-oriented elongate blocks in the central-area.
|Other forms - mostly cavate|
Holococcoliths with a proximal plate of three blocks and tall, tapering spines.
Elliptical, cavate (and usually septate) holococcoliths, often bearing hollow spines. Distal surfaces may be perforate and there may be internal buttresses.
Cavate holococcolith with central septum
Cavate, conical-flask shaped holococcolith with lid and internal partition.
Conical shaped holococcolith, usually seen in side view, base weak or absent
Cavate holococcoliths with thin rims and small spines; whole holococcolith behaves as a single crystal in xpl,
Domed-shaped holococcoliths with holes or cavities.
Solid, truncated-cone-shaped nannolith with rectangular cross-section constructed from minute, roughly equidimensional crystallites. Possibly a holococcolith.
Holococcoliths usually seen in side view and comprising a thick proximal plate and spine or process, typically with a cavity or axial canal.
Holoccolith with elliptical base and five-rayed process
Cavate holococcolith with internal walls and distal protrusions
Cavate holococcolith with box-shape, high rim and thin proximal plate, short spine on distal surface
Farinacci & Howe catalog pages: Rarer genera [no catalog entry yet]
Distinguishing features: Less common generaSearch data:
|Metrics||Lith size: 0->0µm;|
Last occurrence (top): at top of Thanetian Stage (100% up, 56Ma, in Thanetian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Toarcian Stage (0% up, 182.7Ma, in Toarcian stage). Data source: Total of range of species in this database
Plot of occurrence data:
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