Nannoconus colomii


Classification: Mesozoic -> Braarudosphaerales -> Nannoconaceae -> Nannoconus -> N. kamptneri group -> Nannoconus colomii
Sister taxa: N. aquitanicus, N. boletus, N. bonetii, N. bronnimannii, N. bucheri, N. calpidomorphus, N. colomii, N. dauvillieri, N. dislocatus, N. globulus, N. kamptneri, N. oviformis, N. vocontiensis, N. wassallii, N. wintereri,

Distinguishing features: Bulbous basal cavity.


Taxonomy:

Citation: Nannoconus colomi (de Lapparent 1931) Kamptner 1938
Rank: Species
Basionym: Lagena colomi de Lapparent 1931
Notes & discussion: Lagena colomii de Lapparent 1931 and Nannoconus steinmanni Kamptner 1931 were the first two Nannoconus species to be described, and both are largish tapering nannoconids.  However, Bronnimann (1955) argued that they are not synonyms but discrete species with N. colomii having a central cavity which is wider at the base. Following this most authors have used N. steinmanni as the name for the typical, abundant form, and there seem to be few records of N. colomii sensu Bronnimann. Some other authors, however, notably Thierstein (1973) still regarded N. colomii as a senior synonym of N. steinmannii, so most records of N. colomii in the literaure are probably of forms which would be included in N. steinmannii by most modern workers.

Farinacci & Howe catalog pages: L. colomi *

Distinguishing features: Bulbous basal cavity.

Search data:
TagsLITHS: nannolith-radiate, circular, cylindrical, hollow, CA: vacant, CROSS-POLARS: T-prominent,
MetricsLith size: 8->15µm;
Data source notes: assumed similar to N. steinmanni
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Barremian Stage (126.30-130.77Ma, top in Barremian stage). Data source: Perch-Nielsen 1985
First occurrence (base): within Tithonian Stage (145.01-152.06Ma, base in Tithonian stage). Data source: Perch-Nielsen 1985

Plot of occurrence data:

References:

Brönnimann, P. (1955). Microfossils incertae sedis from the Upper Jurassic and Lower Cretaceous of Cuba. Micropaleontology. 1(28-51): -. gs

de Lapparent, J. (1931). Sur les prétendus "embryons" de Lagena. Compte Rendu Sommaire des Séances de la Société Géologique de France. 15: 222-223. gs

Kamptner, E. (1931). Nannoconus steinmanni novo gen., novo spec., ein merkwurdiges gesteinbildendes Mikrofossil aus dem jungeren Mesozoikum der Alpen. Paläontologische Zeitschrift. 13: 288-298. gs

Thierstein, H. R. (1973). Lower cretaceous calcareous nannoplankton biostratigraphy. Abhandlungen der Geologischen Bundesanstalt. 29: 3-52. gs V O

Wind, F. H. & Cepek, P. (1979). Lower Cretaceous calcareous nannoplankton from DSDP Hole 397A (northwest African Margin). Initial Reports of the Deep Sea Drilling Project. 47A: 221-235. gs V O


nannotaxlogo400px

Nannoconus colomii compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 29-9-2020

Taxon Search:
Advanced Search

Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10734 Go to Archive.is to create a permanent copy of this page - citation notes



Comments (0)

No comments yet on this page. Please do add comments if you spot any problems, or have information to share

Add Comment

* Required information
1000
Captcha Image
Powered by Commentics