pforams@mikrotax - Parvularugoglobigerina alabamensis

Parvularugoglobigerina alabamensis

Classification: pf_cenozoic -> Guembelitrioidea -> Guembelitriidae -> Parvularugoglobigerina -> Parvularugoglobigerina alabamensis
Sister taxa: P. eugubina, P. extensa, P. alabamensis, P. sp.


Citation: Parvularugoglobigerina alabamensis (Liu and Olsson 1992)
Rank: Species
Basionym: Guembelitria alabamensis
Taxonomic discussion: Parvularugoglobigerina alabamensis differs from Guembelitria cretacea by possessing 3½-4 (rather than 3) chambers in the outer whorl. It resembles G. cretacea in its apertural characteristics and presence of pore-mounds. Parvularugoglobigerina alabamensis sensu stricto differs from Parvularugoglobigerina extensa in having a less elongate aperture that does not extend extraumbilically. [Olsson et al. 1999]

Catalog entries: Guembelitria alabamensis

Type images:

Distinguishing features:
Parent taxon (Parvularugoglobigerina): Small, moderate to low trochospire of 2½ whorls of (sub)globular chambers. Chambers gradually increase in size; 3½-7 chambers per whorl, separated by radial and depressed sutures on both spiral and umbilical sides. Umbilicus closed. Aperture umbilical to extraumbilical, comma-shaped arch to long narrow opening in nearly equatorial position; bordered by a slight lip. Microperforate.
This taxon: Test of 2½ whorls, each composed of 3 to 4 inflated subglobular chambers, increasing slowly in size. The aperture is low, centrally located, umbilical, and marked by a distinct lip.

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.


Emended description:


Wall type:


Character matrix
test outline:Lobatechamber arrangement:Trochospiraledge view:Inequally biconvexaperture:Umbilical
sp chamber shape:Inflatedcoiling axis:Highperiphery:N/Aaperture border:Thick lip
umb chbr shape:Inflatedumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Strongly depressedumb depth:Shallowwall texture:Pore moundsshell porosity:Microperforate: <1µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:3.0-4.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Similar species

Geographic distribution
Similar to Parvularugoglobigerina eugubina. [Olsson et al. 1999]

Isotope paleobiology
No data available. [Olsson et al. 1999]

Phylogenetic relations
This species evolved from Guembelitria cretacea. Parvularugoglobigerina alabamensis appears as a morphologically intermediate form between G. cretacea and Parvularugoglobigerina extensa Blow. For example, the apertural characteristics of P. alabamensis more closely resemblethoseofG.cretaceathandothoseoftypicalP. extensa (compare Plates 63 and 65); however, the exact phylogenetic relationship of Parvularugoglobigerina alabamensis to Parvularugoglobigerina extensa is unclear, in part because the first known occurrence of P. extensa is stratigraphically lower than the first known occurrence of P. alabamensis. It appears likely that either P. alabamensis evolved from G. cretacea independently of P. extensa (Liu and Olsson, 1992) or P. alabamensis was ancestral to P. extensa, but the known stratigraphic record of P. alabamensis is incomplete. The first hypothesis is stratigraphically simpler, but evolutionarily more complex, than the second because the former necessarily entails iterative evolution of four-chambered parvularugoglobigerine morphotypes from G. cretacea. [Olsson et al. 1999]

Biostratigraphic distribution

Geological Range:
Notes: Zone Pa to Zone P3b. [Olsson et al. 1999]
Last occurrence (top): within P3b subzone (60.73-61.33Ma, top in Selandian 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. 83


Liu, C. & Olsson, R. K. (1992). Evolutionary radiation of microperforate planktonic foraminifera following the K/T mass extinction event. Journal of Foraminiferal Research. 22: 328-346. 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


Parvularugoglobigerina alabamensis compiled by the pforams@mikrotax project team viewed: 29-11-2022

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