Distinguishing features:
Parent taxon (Polycyclolithaceae): Nannoliths composed of two superposed wall cycles and a central-area which may be closed, open and vacant, or spanned by a diaphragm-like structure. Elements have tangential c-axis orientation.
This taxon: Nannolith formed of four blocks, nannolith shape is approx square with diagonal sutures, elements show tangential crystallographic orientations
Daughter taxa (time control age-window is: 0-800Ma) | ||||
Palaeomicula jacovidesii Medium-sized (4.0–7.0 μm) circular species with four imbricated, triangular, segments positioned along the sinusoidal sutures. | ||||
Palaeomicula maltica Almost square, sutures run to corners of nannolith, elements wedge-shaped and outline notched | ||||
Palaeomicula quadrisphena |
Taxonomy:
Farinacci & Howe catalog pages: Palaeomicula *
Distinguishing features:
Parent taxon (Polycyclolithaceae): Nannoliths composed of two superposed wall cycles and a central-area which may be closed, open and vacant, or spanned by a diaphragm-like structure. Elements have tangential c-axis orientation.
This taxon: Nannolith formed of four blocks, nannolith shape is approx square with diagonal sutures, elements show tangential crystallographic orientations
Morphology:
Phylogenetic relations
LITHS: nannolith-radiate, circular, quadrate, CA: closed, CROSS-POLARS: T-prominent, |
Lith size: 3->7µm; Segments: 4->4; Data source notes: size range of included species |
Geological Range:
Last occurrence (top): at top of Hauterivian Stage (100% up, 126.5Ma, in Barremian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within Kimmeridgian Stage (149.24-154.78Ma, base in Kimmeridgian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Varol, O. & Jakubowski, M. (1989). Some new nannofossil taxa. INA Newsletter. 11(1): 24-29. gs Worsley, T. R. (1971). Calcareous nannofossil zonation of Upper Jurassic and Lower Cretaceous sediments from the Western Atlantic. In, Farinacci, A. (ed.) Proceedings of the Second Planktonic Conference Roma 1970. Edizioni Tecnoscienza, Rome 2: 1301-1321. gs OReferences:
Palaeomicula compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 9-9-2024
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10848 Go to Archive.is to create a permanent copy of this page - citation notes |
This policy contains information about your privacy. By posting, you are declaring that you understand this policy:
This policy is subject to change at any time and without notice.
These terms and conditions contain rules about posting comments. By submitting a comment, you are declaring that you agree with these rules:
Failure to comply with these rules may result in being banned from submitting further comments.
These terms and conditions are subject to change at any time and without notice.
Comments