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Praeglobotruncana oraviensis


Classification: pf_mesozoic -> Hedbergellidae -> Praeglobotruncana -> Praeglobotruncana oraviensis
Sister taxa: P. algeriana, P. clotensis, P. compressa, P. delrioensis, P. gibba, P. hilalensis, P. inermis, P. kalaati, P. oraviensis, P. pseudoalgeriana, P. shirakinensis, P. stephani, P. sp.,

Taxonomy

Citation: Praeglobotruncana oraviensis Scheibnerova 1960
Rank: Species
Synonyms:
Taxonomic discussion: P. oraviensis and P. oraviensis trigona (Fig. 14, 8A-C) were described by Scheibnerova as co-occurring in lower Turonian as- semblages and distinguished only because the latter subspecies possesses a trigonal, rather than rounded test. We believe that the shape of the test is not a reliable criterion to discriminate between P. oraviensis and P. oraviensis trigona, because of the very high morphologic plasticity of praeglobotruncanids in this stratigraphic interval. Accordingly, we consider P. oraviensis and P. oraviensis trigona as synonyms. [Falzoni et al. 2016]

P. oraviensis considered to fall within the range of variability of Praeglobotruncana gibba according to Robaszynski et al. (1979) and overlooked in the literature. However, specimens here assigned to P. oraviensis (Fig. 14, 9-10) show very distinctive morphological features, are common in the assemblage above the level of their first appearance and most importantly, first occur slightly below the C/T boundary at Clot Chevalier (Fig. 2). Therefore, we consider P. oraviensis as a valid species, whose appearance might represent a promising tool for correlation when calibrated in other sections. [Falzoni et al. 2016]

Type images:

Original description: Diagnóza: formy s 6—7 komôrkami v poslednom závite, s kýlom, ktorý oby­ čajne u niekoľkých posledných komôrok chýba, s ústím intermarginálnym a intra- umbilikálnym bez akcesorických apertúr, s úzkym a hlbokým umbilikom.

Entries in the Catalog of original descriptions: Praeglobotruncana oraviensis


Diagnostic characters:

Differs from all other Praeglobotruncana species by having a very lobate test and semi-circular to nearly sub- circular chambers and depressed sutures in the outer spiral whorl. [Falzoni et al. 2016]


Emended description: Medium- to large-sized trochospiral test, high trochospire, macroperforate wall; circular to trigonal outline, asymmetrical lateral profile with convex spiral side and concave umbilical side; equatorial periphery lobate with one thick row of pustules at least at the beginning of the last whorl; 5 to 8 chambers in the last whorl, slowly to very slowly increasing in size as added. Spiral side with semi-circular to sub-circular chambers in the last whorl; chamber surface smooth to slightly pustulose and inflated; sutures curved, raised and keeled in the inner whorl, generally depressed in the outer whorl. Umbilical side with triangular to sub-trapezoidal chambers; chamber surface inflated and pustulose; sutures straight and depressed. Primary aperture extraumbilicaleumbilical; umbilical area about 1/3 of the maximum diameter. [Falzoni et al. 2016]

Geological Range:
Notes: FAD near top of OAE2, below C/T boundary (Falzoni et al. 2016)
Last occurrence (top): within Early Turonian Substage (92.90-93.90Ma, top in Turonian stage). Data source: [Falzoni et al. 2016]
First occurrence (base): in mid part of W. archaeocretacea zone (50% up, 93.8Ma, in Cenomanian stage). Data source: Falzoni et al. 2016 (fig2)

Plot of occurrence data:

Dec 2017 - Plotting of Neptune data has been re-enabled on the Mesozoic pages following revision of the age-models in Neptune. The data is, however, still very sparse for the Early Cretaceous

  • Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
  • Note to users in China - the diagram may not plot unless you use a VPN since I use google services on the website. If this is a problem please contact me 谢谢.
  • Taxon plotted: Praeglobotruncana oraviensis, synonyms included - Praeglobotruncana oraviensis; Praeglobotruncana oraviensis oraviensis; Praeglobotruncana oraviensis scheibnerova;
  • space-time plot :: Samples map :: Parent: Praeglobotruncana

    References:

    Falzoni, F., Petrizzo, M. R., Jenkyns, H. C., Gale, A. S. & Tsikos, H. (2016). Planktonic foraminiferal biostratigraphy and assemblage composition across the Cenomanian–Turonian boundary interval at Clot Chevalier (Vocontian Basin, SE France). Cretaceous Research. 59: 69-97. gs

    Scheibnerova, V. (1960). Poznamky rodu Praeglobotruncana Bermudez y kysuckych vrstiev bradloveho pasma. Geologický zborník : geologica Carpathica. 11: 85-90. gs


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    Praeglobotruncana oraviensis compiled by the pforams@mikrotax project team viewed: 9-12-2019

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    Short stable page link: http://mikrotax.org/pforams/index.php?id=110434 Go to Archive.is to create a permanent copy of this page - citation notes



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