Watznaueria contracta


Classification: Mesozoic -> Watznaueriales -> Watznaueriaceae -> Watznaueria -> Watznaueria contracta
Sister taxa: W. barnesiae, W. bayackii, W. fossacincta, W. manivitiae, W. ovata, W. britannica, W. reinhardtii, W. biporta, W. cynthae, W. contracta, W. okadai, W. quadriradiata, W. fasciata, W. rawsonii, C. baticlypeata, W. sp.,

Distinguishing features: Medium to large, broadly elliptical Watznaueria with narrow central area almost filled with axial cross bars.


Taxonomy:

Citation: Watznaueria contracta (Bown & Cooper, 1989) Cobianchi et al. 1992
Rank: Species
Basionym: Lotharingius contractus Bown & Cooper, 1989
Variants:

Farinacci & Howe catalog pages: Lotharingius contractus * , Watznaueria colacicchii * ,

Distinguishing features: Medium to large, broadly elliptical Watznaueria with narrow central area almost filled with axial cross bars.


Morphology remarks: This is a mid-Jurassic species associatied with the evolion of Watznaueria from Lotharingius and is  well-separated in time from the later species with an axial cross.

Evolution & Phylogeny: Apparently a transitional form between Watznaueria and Lotharingius (Bown & Cooper 1988, p.39)

Geological Range:
Last occurrence (top): within NJ12a subzone (165.55-166.40Ma, top in Callovian stage). Data source: Bown & Cooper 1998
First occurrence (base): at base of NJ8b subzone (0% up, 171.8Ma, in Aalenian stage). Data source: Bown & Cooper 1998 (fig 4) - zonal event;Mattioli & Erba 1999, fig. 12 (slightly later)

Plot of occurrence data:

  • (NB There is no histogram as there are no occurrence records for the taxon in the Neptune database) Parent: Watznaueria

    References:

    Bown, P. R. & Cooper, M. K. E. (1989b). New calcareous nannofssils from the Jurassic. Journal of Micropalaeontology. 8: 91-96. gs

    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

    Cobianchi, M., Erba, E. & Pirini-Radrizzani, C. (1992). Evolutionary trends of calcareous nannofossil genera Lotharingius and Watznaueria during the Early and Middle Jurassic

    . Memorie di Scienze Geologiche di Padova. 43: 19-25. gs

    Mattioli, E. & Erba, E. (1999). Synthesis of calcareous nannofossil events in Tethyan lower and middle Jurassic successions. Rivista Italiana di Paleontologia e Stratigrafia. 105(3): 343-376. gs

    Mattioli, E. (1996). New calcareous nannofossil species from the Early Jurassic of Tethys. Rivista Italiana di Paleontologia e Stratigrafia. 102(3): 397-412. gs


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    Watznaueria contracta compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-7-2019

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10595 Go to Archive.is to create a permanent copy of this page - citation notes



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