Nannotax3 - ntax_mesozoic

Nannotax3 - ntax_mesozoic - Nannoconaceae Nannotax3 - ntax_mesozoic - Nannoconaceae

Nannoconaceae

Classification: ntax_mesozoic -> Braarudosphaerales -> Nannoconaceae
Sister taxa: Braarudosphaeraceae, Transitional genera, Nannoconaceae ⟩⟨ Polycyclolithaceae, Other nannoliths with tangential c-axes

Distinguishing features:
Parent taxon (Braarudosphaerales): Nannoliths formed of multiple layers of thin elements, arranged with rotational symmetry, and showing tangential c-axis orientations.
This taxon: Conical, globular or cylindrical nannoliths composed of plates spirally-arranged around an axial cavity or canal. Plate c-axes are arranged tangentially to the longitudinal axis.

Daughter taxa (time control age-window is: 0-800Ma)		Granddaughter taxa
	Faviconus Long, narrow columnar nannoliths formed from stacks of calcite laths around a narrow axial canal. May occur as linked groups of multiple columns.	Faviconus multicolumnatus Faviconus sp.
	Nannoconus Conical, globular or cylindrical nannoliths composed of plates spirally-arranged around an axial cavity (~>1µm in width) or canal (~<1µm in width). Plate c-axes are arranged tangentially to the longitudinal axis.	N. steinmannii group N. kamptneri group N. abundans group N. truittii group N. circularis group N. compressus group Nannoconus - atypical Nannoconus sp.

Taxonomy:

Citation: Nannoconaceae Deflandre, 1959

taxonomic rank: Family

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

Morphology:

For an explanation of general nannoconid morphology and terminology see van Niel (1994) and Young et al. (1997).

Phylogenetic relations

Faviconus has long been included in the Nannoconaceae on the grounds that it seems to be a less organised precursor. However, Hexalithus and Polycyclolithus represent alternative possible ancestors and the two possibilities are not obviously compatible. [editor's comment - JRY 2019]

Search data:

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): at top of Campanian Stage (100% up, 72.1Ma, in Campanian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within NJ15b subzone (152.29-158.53Ma, base in Oxfordian stage). Data source: Total of ranges 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: Braarudosphaerales

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. gs O

Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 132-199. gs O

Deflandre, G. (1959). Sur les nannofossiles calcaires et leur systématique. Revue de Micropaléontologie. 2: 127-152. gs

van Niel, B. E. (1994a). A review of the terminology used to describe the genus Nannoconus (calcareous nannofossil, incertae sedis). Cahiers de Micropaléontologie. 9: 27-47. gs