Muricohedbergella monmouthensis


Classification: pf_cenozoic -> Globanomalidae -> Muricohedbergella -> Muricohedbergella monmouthensis
Sister taxa: M. holmdelensis, M. monmouthensis, M. sp.,

Taxonomy

Citation: Muricohedbergella monmouthensis (Olsson 1960)
Rank: Species
Basionym: Globorotalia monmouthensis Olsson 1960
Synonyms:
Taxonomic discussion: Liu and Olsson (1994) showed that a variety of morphotypes existed within an assemblage of H. monmouthensis. This species is regarded as ancestral to the normal perforate cancellate species of the earliest Danian, which also have the general shape of these morphotypes. Thus, it is believed that these variations may have established trends that resulted in the separation of the Paleocene globigerinids and globorotaliids. Very primitive pore pits can be observed in the chamber walls of H. monmouthensis. In the earliest Danian this character was strongly developed, resulting in the cancellate wall texture that is the most important distinguishing feature of Cenozoic planktonic foraminifera. Two important cancellate groups of planktonic foraminifera are derived from H. monmouthensis, cancellate spinose and cancellate nonspinose. Eoglobigerina and Parasubbotina represent the first of the cancellate spinose genera, and Praemurica represents the first of the cancellate nonspinose genera. A discussion of these transitions is given in Liu and Olsson (1994). [Olsson et al. 1999]

Recombined as Muricohedbergella monmouthensis by Huber & Leckie 2011

Catalog entries: Globorotalia monmouthensis

Type images:

Distinguishing features: Final whorl chambers inflated and rapidly increase in size; periphery distinctly lobulate .

NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus.
They are being edited as the site is developed and comments on them are especially welcome.

Description


Diagnostic characters: This small species has 5 to 5½ inflated chambers in the ultimate whorl that rapidly increase in size. The penultimate whorl is composed of 7 or more spherical chambers that increase slowly in size. The periphery is distinctly lobulate and the surface of the test is relatively smooth and evenly covered with small pustules. The axial periphery is imperforate but is pierced by occasional pores. The aperture is a high rounded umbilical-extraumbilical arch that is bordered by a thin, narrow lip. [Olsson et al. 1999]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Inequally biconvexaperture:Extraumbilical-peripheral
sp chamber shape:Inflatedcoiling axis:Very lowperiphery:N/Aaperture border:Thick lip
umb chbr shape:Inflatedumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Strongly depressedumb depth:Deepwall texture:Spinoseshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:5.0-6.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Worldwide in the high and lower latitudes (Figure 14). [Olsson et al. 1999]
Aze et al. 2011 summary: Cosmopolitan; based on Olsson et al. (1999)

Isotope paleobiology: Hedbergella monmouthensis has among the most positive ∂18O of any Cretaceous trochospiral planktic foraminifer (Boersma et al., 1979). The ∂18O of H. monmouthensis is similar to Abathamphalus mayaroensis and is distinctly more positive than Rugoglobigerina rotundata, R. rugosa, Globotruncanella petaloidea, and Globotruncana area (Berggren and Norris, 1997). The ∂13C of H. monmouthensis is lighter than coexisitng Rugoglobigerina. [Olsson et al. 1999]
Aze et al. 2011 ecogroup 3 - Open ocean thermocline. Based on light δ13C and relatively heavy δ18O. Sources cited by Aze et al. 2011 (appendix S3): Berggren & Norris (1997)

Phylogenetic relations: The species originates in the upper Maastrichtian from H. holmdelensis. [Olsson et al. 1999]

Most likely ancestor: Muricohedbergella holmdelensis - at confidence level 3 (out of 5). Data source: Olsson et al. 1999.

Biostratigraphic distribution

Geological Range:
Notes: Upper Maastrichtian to lower Zone P0. [Olsson et al. 1999]
Last occurrence (top): in lower part of P0 zone (40% up, 66Ma, in Danian stage). Data source: Olsson et al. 1999
First occurrence (base): within G. gansseri zone (71.75-72.97Ma, base in Campanian stage). Data source: Olsson et al. 1999

Plot of occurrence data:

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 35

References:

Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. 1-252. gs


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Muricohedbergella monmouthensis compiled by the pforams@mikrotax project team viewed: 22-11-2019

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Short stable page link: http://mikrotax.org/pforams/index.php?id=104395 Go to Archive.is to create a permanent copy of this page - citation notes



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