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Liuenella


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



Specimens which cannot be assigned to established species

Taxonomy

Citation: Liuenella  Georgescu 2010
Rank: Genus
Type species: Liuenella falklandica (Georgescu, 2008)
Synonyms:
Taxonomic discussion: Liuenella 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, Liuenella 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:

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.

Description. Test low to very low trochospiral with globular to  subglobular   chambers,  separated  by  straight,  incised  and radial sutures. Test biconvex, nearly symmetrical in edge view. Periphery broadly rounded with a wide imperforate  band throughout the final whorl. Main  aperture  is in the shape of a low to medium high arch, peripheral-umbilical in position  and bordered by an imperforate  lip. Test wall calcitic, hyaline, perforate, with perforation diameters  ranging between 1.7 and 3.1 mm. Test surface smooth.

Entries in the Catalog of original descriptions: Liuella; Liuenella;

Distinguishing features: 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:

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

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.

Georgescu, M.D., (2010). Liuenella, new name for Liuella Georgescu, 2008. Journal of Foraminiferal Research, 40: 206.


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Liuenella compiled by the pforams@mikrotax project team viewed: 18-10-2018

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Short stable page link: http://mikrotax.org/pforams/index.php?id=110315Go to Archive.is to create a permanent copy of this page - citation notes



Comments (1)

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Le Coze

Liuella Georgescu, 2008 is a junior homonym of Liuella Wang & Bai, 1992 (Arthropoda, Chelicerata, Arachnida) and was given the replacement name Liuenella in Georgescu, 2010

see: http://www.marinespecies.org/foraminifera/aphia.php?p=taxdetails&id=1034676

Cheers,

François

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Jeremy Young (UK)

Thanks I will rename this

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