Distinguishing features:
Parent taxon (Podorhabdales): Placolith (or modified placolith) coccoliths showing little or no imbrication. Typically, V-units form distal shield, R-units form proximal shield.
This taxon: Three-shielded placoliths; central-area wide, spanned by bars, grill, net or plate.
The distal shield may be high and flaring, formed from non-imbricating elements, joined along radial sutures. LM image is generally dark, but birefringence increases when the distal shield is high.
Daughter taxa (time control age-window is: 0-800Ma) | Granddaughter taxa | ||||
 |  |  |  | Mazaganella Three-shielded placoliths with a wide central-area spanned by a variety of bars, grills, nets or plates. The distal shield may be high and flaring. The distal shield is formed from non-imbricating elements, joined along radial sutures. LM image is generally dark, but birefringence increases when the distal shield is high. | |
 |  |  |  | Triscutum Three-shielded placoliths with a wide central-area spanned by a proximal net or grill. | |
Taxonomy:
Farinacci & Howe catalog pages: Mazaganellaceae [no catalog entry yet]
Distinguishing features:
Parent taxon (Podorhabdales): Placolith (or modified placolith) coccoliths showing little or no imbrication. Typically, V-units form distal shield, R-units form proximal shield.
This taxon: Three-shielded placoliths; central-area wide, spanned by bars, grill, net or plate.
The distal shield may be high and flaring, formed from non-imbricating elements, joined along radial sutures. LM image is generally dark, but birefringence increases when the distal shield is high.
Morphology: Three-shielded placoliths with a wide central-area spanned by a variety of bars, grills, nets or plates. The distal shield may be high and flaring. The distal shield is formed from non-imbricating elements, joined along radial sutures. LM image is generally dark, but birefringence increases when the distal shield is high.
| Tags | LITHS: placolith, ca_disjunct, |
| Metrics | Lith size: 0->0µm; |
Geological Range:
Last occurrence (top): in upper part of Oxfordian Stage (61% up, 159.7Ma, in Oxfordian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Sinemurian Stage (0% up, 199.3Ma, in Hettangian stage). Data source: Total of range of species in this database
Plot of occurrence data:
Bown, P. R. & Cooper, M. K. E. (1998). Jurassic. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 34-85. gs Bown, P. R. (1987a). Taxonomy, evolution, and biostratigraphy of Late Triassic-Early Jurassic calcareous nannofossils. Special Papers in Palaeontology. 38: 1-118. gsReferences:
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Mazaganellaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 18-10-2021
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10648 Go to Archive.is to create a permanent copy of this page - citation notes |
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