Prinsiaceae


Ancestry: Coccolithophores -> Isochrysidales -> Prinsiaceae
Sister taxa: Noelaerhabdaceae, Prinsiaceae, Isochrysidaceae,

Short diagnosis: Placoliths with R-units forming the lower layer of proximal shield, inner tube and middle tube; V-units forming an upper layer to the proximal shield, outermost tube and the distal shield. In LM they display a dark outer cycle and brighter inner cycle. Central-area structures are conjunct, formed from the R-units.


Daughter taxa (blue => in age window 0-300Ma) Granddaughter taxa
Very small circular to elliptical placoliths with narrow central area and tube-elements extended distally to form an elevated flower-like distal structure.

Elliptical placoliths with bicyclic distal shields with raised tube cycle and central area grill formed from robust bars.

Very small to small placoliths with closed or narrow central areas. Shields are dark in XPL with bright tube cycle.

 Prinsiacean placoliths with narrow central areas that are closed or have a narrow opening that may be spanned by a narrow plate/net. Typically very  small to medium sized.

Elliptical to circular prinsiacean placoliths with central areas that are typically spanned by a proximal net and/or distal conjunct nets or bars. Typically medium sized.



Taxonomy:

Citation: Prinsiaceae Hay & Mohler, 1967 emend. Young & Bown, 1997
Rank: Family
Notes & discussion: Toweius coccoliths are larger than Prinsius, with wider central areas and therefore more clearly visible central area nets in LM. Similarly, Futyania coccoliths are similar to Prinsius but have distally elevated tube elements.

Farinacci & Howe catalog pages:

Short diagnosis: Placoliths with R-units forming the lower layer of proximal shield, inner tube and middle tube; V-units forming an upper layer to the proximal shield, outermost tube and the distal shield. In LM they display a dark outer cycle and brighter inner cycle. Central-area structures are conjunct, formed from the R-units.


Morphology remarks: Typically small to medium sized placoliths with R-units forming the proximal shield-element and two tube-elements, and V-units forming an upper layer to the proximal shield, an outermost tube and the distal shield. In LM they display a dark outer cycle and brighter inner cycle. Central-area structures are conjunct, being formed from either the central-area elements or the inner tube-elements of the proximal shield.

Evolution & Phylogeny: Toweius gave rise to Reticulofenestra by loss of the V-units - the middle tube cycle of Prinsiaceae forms the outer tube of reticulofenestrids and extends to form the distal shield - see Gallagher (1989) and Young (1989). The similariy of the structures are much clearer in proximal view than distal view.

Geological Range:
Last occurrence (top): within Lutetian Stage (41.15-47.84Ma, top in Lutetian stage). Data source: Total of range of species in this database
First occurrence (base): within Danian Stage (61.61-66.04Ma, base in Danian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Gallagher, L.T., (1989). Reticulofenestra : A critical review of taxonomy, structure and evolution. In: Crux, J.A. and Heck, S.E.v. (Editors), Nannofosils and their applications. Ellis Horwood, Chichester, pp. 41-75.

Hay, W.W. & Mohler, H.P., (1967). Calcareous nannoplankton from Early Tertiary rocks at Point Labau, France and Paleocene-Early Eocene correlations. Journal of Paleontology, 41(6): 1505-1541.

Perch-Nielsen, K., (1985). Cenozoic calcareous nannofossils. In: Bolli, H.M., Saunders, J.B. and Perch-Nielsen, K. (Editors), Plankton Stratigraphy. Cambridge University Press, Cambridge, pp. 427-555.

Young, J.R. & Bown, P.R., (1997). Cenozoic calcareous nannoplankton classification. Journal of Nannoplankton Research, 19(1): 36-47.

Young, J.R., (1989). Observations on heterococcolith rim structure and its relationship to developmental processes. In: Crux, J.A. and Heck, S.E.v. (Editors), Nannofossils and their applications. Ellis Horwood, Chichester, pp. 1-20.


Nannotax3 - Coccolithophores - Prinsiaceae by: Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 28-4-2017

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