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.
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. Size:
Search data:
CA: placolith, ca_disjunct,
Lith size: 0->0µm;
The morphological data given here can be used on the advanced search page. See also these notes
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:
Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Neptune data: this is a higher taxon page so Neptune data is not plotted. For the customisable plot option go to a genus page Parent: Podorhabdales
References:
Bown, P. R. & Cooper, M. K. E. (1998). Jurassic. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 34-85. gsO
Bown, P. R. (1987a). Taxonomy, evolution, and biostratigraphy of Late Triassic-Early Jurassic calcareous nannofossils. Special Papers in Palaeontology. 38: 1-118. gs
Mazaganellaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 3-10-2022
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