pforams@mikrotax - Liuenella

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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)
			Liuenella falklandica
			Liuenella globigerinellinoides
			Liuenella punctata
			Liuenella sp. Specimens which cannot be assigned to established species

Taxonomy

Citation: Liuenella Georgescu 2010

Rank: Genus

Type species: Liuella falklandica nov. sp. Georgescu, 2008

Synonyms:

Liuella Georgescu 2008 (this was a homonym of an arthropod and so changed to Liuenella)

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:

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;

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

Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Neptune data: This is a higher taxon page so Neptune data is not plotted. See also: customisable plot Parent: Hedbergellidae

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.

Liuenella compiled by the pforams@mikrotax project team viewed: 25-6-2018

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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

16th September 2017 12:09pm