Distinguishing features:
Parent taxon (placoliths inc sedis):
This taxon: Unicyclic, elliptical and circular placolith coccoliths with a narrow or closed central area and a characteristically dark gray (low birefringence) XPL image.
Daughter taxa (time control age-window is: 0-800Ma) | ||||
Haqius circumradiatus Large (8-10 µm) circular Haqius species. | ||||
Haqius ellipticus Large (7-15µm) elliptical Haquis species | ||||
Haqius peltatus Small to medium (3-7 µm) elliptical Haquis species | ||||
Haqius sp. Specimens not identified to species level |
Taxonomy:
Farinacci & Howe catalog pages: Haqius *
Distinguishing features:
Parent taxon (placoliths inc sedis):
This taxon: Unicyclic, elliptical and circular placolith coccoliths with a narrow or closed central area and a characteristically dark gray (low birefringence) XPL image.
Morphology:
LITHS: placolith, circular, elliptical, CROSS-POLARS: rim-unicyclic, V-prominent, |
Lith size: 3->10µm; Data source notes: size range of included species |
Geological Range:
Last occurrence (top): at top of UC15d subzone (100% up, 75.9Ma, in Campanian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within Late Tithonian Substage (143.10-145.00Ma, base in Tithonian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Lower Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 86-131. gs O Roth, P. H. (1978). Cretaceous nannoplankton biostratigraphy and oceanography of the northwestern Atlantic Ocean. Initial Reports of the Deep Sea Drilling Project. 44: 731-760. gs Stover, L. E. (1966). Cretaceous coccoliths and associated nannofossils from France and the Netherlands. Micropaleontology. 12(2): 133-167. 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:
Haqius compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 19-9-2024
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10490 Go to Archive.is to create a permanent copy of this page - citation notes |
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