arrayname: original
Taxonomy:
Distinguishing features:
Parent taxon (Lithostromation): Triangular to stellate nannoliths with porous structure formed from small crystallites. All show 3-fold symetry but with a wide range of forms.
This taxon: Medium-sized (5-10 µm), sub-circular
Farinacci & Howe catalog pages: P. operosus * , T. conglobatus *
"This species has a spherical body with an irregular, knobby surface and numerous circular depressions. Each depression is surrounded by a hexagonal ridge with a knob at each corner of the hexagon. Some specimens have six large projections evenly spaced around the equator of the sphere. There are no discernible crystal elements and L. operosum is dark under cross-polarized light." [c]
Morphology:
LITHS: nannolith-radiate, star-shaped, CA: pores, CROSS-POLARS: V-prominent, 1ou, |
Lith size: 5->10µm; Segments: 6->6; Data source notes: lith size from ODs & illustrated specimens |
Geological Range:
Last occurrence (top): within Oligocene Epoch (23.03-33.89Ma, top in Chattian stage). Data source: [JRY rough estimate]
First occurrence (base): within Eocene Epoch (33.89-55.96Ma, base in Ypresian stage). Data source: [JRY rough estimate]
Plot of occurrence data:
Bramlette, M. N. & Sullivan, F. R. (1961). Coccolithophorids and related nannoplankton of the Early Tertiary in California. Micropaleontology. 7(2): 129-188. gs Bybell, L. (1975). Middle Eocene calcareous nannofossils at Little Stave Creek, Alabama. Tulane Studies in Geology and Paleontology. 11(4): 177-247. gs O de Kaenel, E. & Villa, G. (1996). Oligocene-Miocene calcareous nannofossil biostratigraphy and paleoeecology from the Iberian Abyssal Plain. Proceedings of the Ocean Drilling Program, Scientific Results. 149: 79-145. gs O Deflandre, G. & Fert, C. (1954). Observations sur les coccolithophoridés actuels et fossiles en microscopie ordinaire et électronique. Annales de Paléontologie. 40: 115-176. gs Self-Trail, J. (2011). Paleogene Calcareous Nannofossils of the South Dover Bridge core, Southern Maryland (USA). Journal of Nannoplankton Research. 32(1): 1-28. gs Stradner, H. (1962). Über neue und wenig bekannte Nannofossilien aus Kreide und Alttertiär. Verhandlungen der Geologischen Bundesanstalt (Wien). 2: 363-377. gs References:
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Lithostromation operosum compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 25-3-2025
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=823 Go to Archive.is to create a permanent copy of this page - citation notes |
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