Daughter taxa (time control age-window is: 0-800Ma) | Granddaughter taxa | ||||
Biscutaceae Placoliths with two broad shields; central area narrow; distal shield formed from V-units; proximal shield and tube formed from R-units. | |||||
Chiastozygaceae Loxolith coccoliths with variably-developed proximal/inner-cycles and a central-area spanned by axial, non-axial or diagonal crossbars or a single transverse bar. LM image includes both unicyclic and bicyclic types. Outer rim clockwise-imbricate. | |||||
Markalius Circular placoliths with moderately birefringent shields, bright inner tube cycle and narrow or closed central areas. | Markalius apertus Markalius inversus Markalius latus Markalius neuquenensis Markalius walvisensis Markalius sp. | ||||
Watznaueriaceae Placoliths or modified placoliths with R-unit well developed, forming proximal and distal shield elements with opposite senses of imbrication; the V-unit typically forms a narrow distal cycle near the inner edge of the shield. Central-area structures are typically disjunct. Birefringent LM image, in which the V-unit cycle appears only as a thin, dark line. |
Taxonomy:
Distinguishing features:
Parent taxon (ntax_cenozoic): Extant coccolithophores and Cenozoic calcareous nannofossils - Mesozoic nannofossils are in a separate module
This taxon: Mesozoic taxa which occur in low abundances in the early Palaeogene.
Farinacci & Howe catalog pages: Mesozoic Survivors [no catalog entry yet]
Phylogenetic relations
See also: Braarudosphaera bigelowii ;Calciosolenia ;Cruciplacolithus primus - other Cretaceous survivors, in major groups;
Search data:Lith size: 3->13.5µm; |
Geological Range:
Notes: Most of these taxa only occur in the Palaeocene, however, the Watznaueriacean cocolith Tergestiella adriatica is now known to still be extant (Hagino et al. 2015).
Last occurrence (top): Extant. Data source: Total of ranges of the species in this database
First occurrence (base): within Jurassic Period (143.10-201.36Ma, base in Hettangian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Bown, P. R. (2005e). Selective calcareous nannoplankton survivorship at the Cretaceous-Tertiary boundary. Geology. 33(8): 653-656. gs Bramlette, M. N. & Martini, E. (1964). The great change in calcareous nannoplankton fossils between the Maestrichtian and Danian. Micropaleontology. 10(2): 291-322. gs Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 132-199. gs O Hagino, K. et al. (2015). Re-discovery of a “living fossil” coccolithophore from the coastal waters of Japan and Croatia. Marine Micropaleontology. 116(1): 28-37. gs Jiang, S., Bralower, T. J., Patzkowsky, M. E., Kump, L. R. & Schueth, J. D. (2010). Geographic controls on nannoplankton extinction across the Cretaceous/Palaeogene boundary. Nature Geoscience. 3(4): -. gs MacLeod, N. et al. (1997). The Cretaceous-Tertiary biotic transition. Journal of the Geological Society of London. 1254(265-293): -. gs Mai, H., von Salis, K., Willems, H. & Romein, A. J. T. (1997). Fossil coccospheres from the K/T boundary section from Geulhemmerberg, The Netherlands. Micropaleontology. 43: 281-303. gs Medlin, L. K., Sáez, A. G. & Young, J. R. (2008). A molecular clock for coccolithophores and implications for selectivity of phytoplankton extinctions across the K/T boundary. Marine Micropaleontology. 67(1-2): 69-86. gs Pospichal, J. J. (1996). Calcareous nannoplankton mass extinction at the Cretaceous/Tertiary boundary: An update, in Ryder, G., et al., eds., The Cretaceous-Tertiary event and other catastrophes in Earth history. Geological Society of America, Special Papers. 307: 335-360. gs Schulte, P. et al. (2010). The Chicxulub asteroid impact and mass extinction at the Cretaceous-Paleogene boundary. Science. 327: 1214-1218. gs Young, J. R. & Bown, P. R. (1997). Cenozoic calcareous nannoplankton classification. Journal of Nannoplankton Research. 19(1): 36-47. gs References:
Mesozoic Survivors compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 14-12-2024
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=850 Go to Archive.is to create a permanent copy of this page - citation notes |
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