Parasubbotina aff. pseudobulloides


Classification: pf_cenozoic -> Globigerinidae -> Parasubbotina -> Parasubbotina aff. pseudobulloides
Sister taxa: P. griffinae, P. eoclava, P. hagni, P. prebetica, P. inaequispira, P. pseudowilsoni, P. variospira, P. varianta, P. pseudobulloides, P. aff. pseudobulloides, P. sp.,

Taxonomy

Citation: Parasubbotina aff. pseudobulloides Olsson et al. 1992
Rank: Species
Basionym: Parasubbotina aff. pseudobulloides
Synonyms:
Taxonomic discussion: This small morphotype apparently has often been identified as Globigerina fringa Subbotina, 1953. This species, however, has a coarsely cancellate wall and morphologic characters belonging to Subbotina. Parasubbotina aff. pseudobulloides is smaller than P pseudobulloides, and it has a very weakly developed cancellate wall in contrast to the strongly developed cancellate wall of pseudobulloides. The spinose condition is already present. As the cancellate wall becomes more strongly developed, along with an increase in size, this morphotype grades into P. pseudobulloides. Because of this fact, it is often difficult to consistantly identify the first occurrence of P. pseudobulloides and hence the base of Zone Pla. A more useful criterion for the base of Zone Pla is the last occurrence of Parvularugoglobigerina eugubina (Luterbacher and Premoli Silva). [Olsson et al. 1999]

Catalog entries: Parasubbotina aff. pseudobulloides

Distinguishing features: Test small (<225µm), 4½ to 5 chambers in final whorl. Chambers globular, increase rapidly in size. Aperture high arched umbilical-extraumbilical with a thin lip Wall weakly developed cancellate, spinose.

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: A small, very low trochospiral test with 4½ to 5 chambers in the ultimate whorl, globular chambers which increase rapidly in size, a high arched umbilical-extraumbilical aperture with a thin lip, and a weakly developed cancellate wall, spinose. Maximum diameter less than 225 um. [Olsson et al. 1999]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical-extraumbilical
sp chamber shape:Inflatedcoiling axis:Moderateperiphery:N/Aaperture border:Thin lip
umb chbr shape:Inflatedumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Strongly depressedumb depth:Shallowwall texture:Cancellateshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:4.5-5.5 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology


Geographic distribution: Probably widespread, but few
reliable identifications have been made. [Olsson et al. 1999]

Isotope paleobiology: There are no existing isotope data that are unambiguously attributed to this taxon. Data for P. pseudobulloides from the early Danian show that this taxon has ∂18O and ∂13C similar to Eoglobigerina and distinctly heavier
∂18O than Woodringina (D'Hondt and Zachos, 1993). [Olsson et al. 1999]

Phylogenetic relations: Parasubbotina aff. pseudobulloides
evolved from Hedbergella monmouthensis in Biochron P0 by achieving a more rapid increase in chamber size, by the development of a primitive cancellate wall texture, and by becoming spinose. [Olsson et al. 1999]

Most likely ancestor: benthic ancestor - at confidence level 3 (out of 5). Data source: Olsson et al. 1999 f.5.
Likely descendants: Parasubbotina pseudobulloides;

Biostratigraphic distribution

Geological Range:
Notes: Upper Zone P0 to Zone Pa. [Olsson et al. 1999]
Last occurrence (top): within Pa zone (65.72-66.00Ma, top in Danian stage). Data source: Olsson et al. 1999
First occurrence (base): within P0 zone (66.00-66.04Ma, base in Danian 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. 25

References:

Olsson, R. K., Hemleben, C., Berggren, W. A. & Liu, C. (1992). Wall Texture Classification of planktonic foraminifera genera in the Lower Danian. Journal of Foraminiferal Research. 22(3): 195-213. gs

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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Parasubbotina aff. pseudobulloides compiled by the pforams@mikrotax project team viewed: 23-11-2019

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Short stable page link: http://mikrotax.org/pforams/index.php?id=100226 Go to Archive.is to create a permanent copy of this page - citation notes



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