Nannoliths inc sedis


Classification: Mesozoic -> Nannoliths inc sedis
Sister taxa: Arkhangelskiales, Eiffellithales, Stephanolithiales, Podorhabdales, Watznaueriales, Syracosphaerales, Heterococcoliths inc sedis, Holococcoliths, Braarudosphaerales, Nannoliths inc sedis, Mesozoic non–coccoliths, hidden,

Short diagnosis: Nannofossils not obviously homologous with heterococcoliths, holococcoliths, or braarudosphaerarlids


Daughter taxa (blue => in age window 0-300Ma) Granddaughter taxa
Pentagonal liths, with narrow rim and granular central area plate. Dark image in LM.

Nannoliths with a truncated-cone-like morphology constructed from an outer rim of thin, elements joined along vertical sutures, and an inner core of numerous radial lamellae that may protrude distally.

Hemispherical to tall cylindrical nannoliths, with narrow walls constructed from one to several cycles of thin elements, enclosing a hollow central space; the nannolith tapers distally, and may have apical spines or processes.

Rod-shaped nannoliths.

Nannoliths composed of two superposed wall cycles and a central-area which may be closed, open and vacant, or spanned by a diaphragm-like structure. Elements have tangential c-axis orientation.

Radiate nanoliths formed of multiple elements but lacking a central diaphragm

Nannolith genera without clear affinities to any other genera

Taxonomy:

Citation: Nannoliths inc sedis
Rank: informal group

Farinacci & Howe catalog pages: Nannoliths [no catalog entry yet]

Short diagnosis: Nannofossils not obviously homologous with heterococcoliths, holococcoliths, or braarudosphaerarlids


Morphology remarks: The term nannolith appears to have been introduced by Haq (1978), it is also discussed in e.g. Young et al. (1997). The Mesozoic nannoliths are a very mixed grouping but include many biostratigraphically important taxa.

Geological Range:
Last occurrence (top): within Chattian Stage (23.03-28.09Ma, top in Chattian stage). Data source: Total of range of species in this database
First occurrence (base): within Norian Stage (209.46-228.35Ma, base in Norian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Bown, P.R., (1998). Triassic. In: Bown, P.R. (Editor), Calcareous nannofossil biostratigraphy. British Micropalaeontological Society Publication Series. Chapman & Hall, pp. 29-33.

Haq, B.U., (1978). Calcareous nannoplankton. In: Haq, B.U. and Boersma, A. (Editors), Introduction to marine micropaleontology. Elsevier, Amsterdam, pp. 79-108.

Young, J.R. & others, (1997). Guidelines for coccolith and calcareous nannofossil terminology. Palaeontology, 40: 875-912.


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Nannoliths inc sedis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 11-12-2017

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