Distinguishing features: Murolith (protolith type) coccoliths with bicylic rims and central-areas spanned by an axial-cross or transverse bar bearing a broad, often long, spine.
Daughter taxa (time control age-window is: 0-800Ma)![]() | Granddaughter taxa | ||||
![]() | Bucanthus Protolith coccoliths with low, sloping rim; central area wide with offset central-cross. | ||||
![]() | ![]() | ![]() | Calcivascularis Protolith coccoliths with high rim, inner rim cycle not clearly developed, upper part of coccolith filled by mass of radiating elements. | ||
![]() | ![]() | ![]() | ![]() | Crucirhabdus Protolith coccoliths with low, sloping rim; central area wide with axial cross supporting a tall spine | |
![]() | ![]() | ![]() | Diductius Protolith coccoliths with low, sloping rim; central area wide with a multiperforate net that may incorporate spine-bearing axial cross bars. | ||
![]() | ![]() | ![]() | ![]() | Mitrolithus Protolith coccoliths with high rim with broad proximal/inner rim cycle; central area filled by a massive boss/spine. Often seen in side view | |
![]() | ![]() | ![]() | ![]() | Parhabdolithus Protolith coccoliths with high rim; central area with large spine supported by transverse bar. Often seen in side view | |
![]() | ![]() | ![]() | Timorella Modified protoliths, with tapering, cup-like rim and central-area plate. | ||
![]() | ![]() | ![]() | ![]() | Umbria Protolith coccoliths with low, sloping rim; central area wide filled by blocky laths |
Taxonomy:
Farinacci & Howe catalog pages: Parhabdolithaceae [no catalog entry yet]
Distinguishing features: Murolith (protolith type) coccoliths with bicylic rims and central-areas spanned by an axial-cross or transverse bar bearing a broad, often long, spine.
Morphology: The LM image is usually bicyclic, with the proximal/inner-cycle well-developed and the spine often fills the central area. Commonly observed in side view.
Tags | LITHS: murolith, elliptical, CA: ca_disjunct, CROSS-POLARS: rim-bicyclic, V-prominent, R-prominent, |
Metrics | Lith size: 0->0µm; |
Geological Range:
Last occurrence (top): in lower part of Barremian Stage (30% up, 129.4Ma, in Barremian stage). Data source: Total of range of species in this database
First occurrence (base): in mid part of Norian Stage (50% up, 218.9Ma, in Norian 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. (1987b). The structural development of Early Mesozoic coccoliths and its evolutionary and taxonomic significance. Abhandlungen der Geologischen Bundesanstalt. 39: 33-49. gs V OReferences:
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Parhabdolithaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 23-4-2021
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10855 Go to Archive.is to create a permanent copy of this page - citation notes |