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Liuella


Classification: pf_mesozoic -> Hedbergellidae -> Liuella
Sister taxa: Asterohedbergella, Clavihedbergella, Costellagerina, Falsotruncana, Hedbergella, Helvetoglobotruncana, Liuella, Microhedbergella, Muricohedbergella, Paracostellagerina, Paraticinella, Praeglobotruncana, Pseudoguembelitria, Whiteinella,
Daughter taxa (blue => in age window 0-300Ma)



Taxonomy

Citation: Liuella Georgescu 2008
Rank: Genus
Basionym: Liuella falklandica nov. sp.
Type species: Liuella falklandica nov. sp. Georgescu, 2008
Taxonomic discussion: Liuella nov. gen. differs from any other hedbergellid genus by presenting an imperforate peripheral band throughout the final whorl. It also differs from Clavihedbergella Banner and Blow of the upper Albian by its finely perforate to macroperforate test wall and lack of radially elongate chambers. Seemingly, there is a gap that separates the stratigraphic ranges of the two genera and that spans the Cenomanian-early Santonian interval. Herein, Liuella is included within the Subfamily Hedbergellinae—despite the presence of the imperforate peripheral band—due to the strong general resemblances with the hedbergellid group rather than with the ticinellids of the Subfamily Ticinellinae, such as Biticinella, Clavihedbergella, Claviticinella and Ticinella (Loeblich and Tappan, 1987, p. 466). Pore-size terminology is that used by the Mesozoic Planktonic Foraminifera Working Group (2006, coordinator B. T. Huber): 1.0 to 2.5 mm is considered finely perforate, and over 2.5 mm is considered macroperforate.

Type images:

Original description: Liuella:

Entries in the Catalog of original descriptions: Liuella;

Short diagnosis: Smooth, very low trochospiral test, finely perforate to macroperforate test wall, crater-like pores on the earlier chambers and imperforate peripheral band throughout the final whorl.

Geological Range:
Last occurrence (top): within Campanian Stage (72.05-83.64Ma, top in Campanian stage). Data source: Total of range of species in this database
First occurrence (base): within Santonian Stage (83.64-86.26Ma, base in Santonian stage). Data source: Total of range of species in this database

Plot of occurrence data:

NB Plotting of Neptune data has been disabled on the Mesozoic pages because the dataset is both small and badly affected by a few sites with erroneous age models (our obs Huber, Petrizzo, Young, Nov 2016). The data can still be viewed via the range plottertool - tools menu.

References:

Georgescu, M.D., (2008). A new planktonic foraminifer (Family Hedbergellidae Loeblich and Tappan, 1961) from the lower Campanian sediments of the Falkland Plateau, South Atlantic Ocean (DSDP Site 511). Journal of Foraminiferal Research, 38: 157-161.


Liuella compiled by the pforams@mikrotax project team viewed: 30-3-2017

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