|Daughter taxa (time control age-window is: 0-800Ma)||Granddaughter taxa|
Heterococcoliths asymetric, arranged in meridional rows on coccosphere; V-unit forms flange, R-unit basal. Also nannolith phase "Polycrater" with quadrate aragonitic liths.
Narrow-rimmed muroliths, mostly with prominent central structures.
Placolith-like with distal shield much larger than proximal, predominantly formed from R-units, V-units vestigial.
|narrow rimmed placoliths|
Diverse group of coccoliths with narow placolith rims and variable central structures, usually showing four-fold symmetry.
|Coccolith genera inc sed|
Heterococcolith genera which cannot be assigned to any family
Specimens which cannot be assigned to established taxa
Parent taxon (ntax_cenozoic): Extant coccolithophores and Cenozoic calcareous nannofossils - Mesozoic nannofossils are in a separate module
This taxon: 2N: Various heterococcolith groups not obviously related to the well-defined orders
N: mostly unknown
Farinacci & Howe catalog pages: Coccolith families inc sed [no catalog entry yet]
|Lith size: 0->0µm;|
Last occurrence (top): Extant. Data source: Total of range of species in this database
First occurrence (base): at base of Danian Stage (0% up, 66Ma, in Danian stage). Data source: Total of range of species in this database
Plot of occurrence data:
Coccolith families inc sed compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 23-3-2023
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=311 Go to Archive.is to create a permanent copy of this page - citation notes