pforams@mikrotax - Parvularugoglobigerina extensa

Parvularugoglobigerina extensa

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


Citation: Parvularugoglobigerina extensa (Blow 1979)
Rank: Species
Basionym: Eoglobigerina? extensa
Taxonomic discussion: Parvularugoglobigerina extensa is a moderately high-spired form and is morphologically intermediate between Guembelitria cretacea and Parvularugoglobigerina eugubina. Parvularugoglobigerina extensa primarily differs from G. cretacea sensu stricto by possessing 3½—4 (rather than 3) chambers in the outer whorl and by typically having an elongate aperture that extends extraumbilically. [Olsson et al. 1999]

Eoglobigerina? fodina Blow, 1979, was originally described as characterized by a small but open umbilicus and a circular aperture "extending from the opening in a slightly oblique manner, into the terminal face of the last chamber" (Blow, 1979:1221). The namefodina was derived from the Latin word for pit or tunnel and applied to the apertural shape, which was described as looking like the entrance to a London Underground Railway tunnel (Blow, 1979:1221). The slight differences between the holotypes of extensa and fodina result from elongation of the former's aperture toward the umbilicus. Given the extreme plasticity of apertural morphology and location in related taxa (i.e., Parvularugoglobigerina eugubina and Woodringina species), such minor differences appear insufficient to maintain extensa and fodina as separate taxa. Consequently, we have reduced Eoglobigerina? fodina Blow, 1979, to a junior synonym of Parvularugoglobigerina extensa (Blow, 1979). In addition, the 3½-4 chambered inflated subglobular, microperforate forms described by Premoli Silva and Bolli (1973), Smit (1982), Keller (1988), D'Hondt and Keller (1991), and Liu and Olsson (1992) under various names (see synonomy) are placed in P. extensa. [Olsson et al. 1999]

Although Blow (1979:1220) provisionally placed extensa and fodina in the genus Eoglobigerina, he recognized their microperforate structure as quite "distinct from the normal perforate, cancellate or reticulate, wall of the eobulloides -trivialis-edita group." On that basis, he expressed doubt that assignment of those forms to Eoglobigerina would be maintained in future studies. On the basis of wall structure and texture, Blow (1979) suggested that extensa and fodina (= extensa) were more closely related to Globastica (= Globoconusa) daubjergensis than to any other species assigned to Eoglobigerina. He further hypothesized that "either fodina or extensa might be ancestral to daubjergensis or, alternatively the various forms only share a common ancestor" (Blow, 1979:1221). The latter interpretation is consistent with the present hypothesis that Globoconusa daubjergensis and Parvularugoglobigerina extensa both evolved directly from Guembelitria cretacea (Olsson, 1970, 1982; Premoli Silva, 1977; Smit, 1982; Liu and Olsson, 1992; Olsson et al., 1992). [Olsson et al. 1999]

Catalog entries: Eoglobigerina extensa, Eoglobigerina fodina

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: Like P. alabamensis but aperture is centrally located, umbilical to extraumbilical, marked by a distinct lip, often elongate, and often asymmetrically oriented.

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:Equally biconvexaperture:Umbilical
sp chamber shape:Inflatedcoiling axis:Moderate-highperiphery:N/Aaperture border:Thick porticus
umb chbr shape:Inflatedumbilicus:Absentperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Strongly depressedumb depth:N/Awall texture:Pore moundsshell porosity:Microperforate: <1┬Ám
umbilical or test sutures:Strongly depressedfinal-whorl chambers:4.0-4.0 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. [Olsson et al. 1999]

Most likely ancestor: Parvularugoglobigerina alabamensis - at confidence level 3 (out of 5). Data source: Olsson et al. 1999 fig6, Koutsoukos 2014, fig16.
Likely descendants: Parvularugoglobigerina eugubina; plot with descendants

Biostratigraphic distribution

Geological Range:
Notes: Upper Zone P0 through 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): in upper part of P0 zone (60% up, 66Ma, 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. 85


Blow, W. H. (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea). E. J. Brill, Leiden. 2: 1-1413. gs

D'Hondt, S. & Keller, G. (1991). Some patterns of planktic foraminiferal assemblage turnover at the Cretaceous-Tertiary boundary. Marine Micropaleontology. 17: 77-118. gs

Keller, G. (1988). Extinction, Survivorship, and Evolution across the Cretaceous/ Tertiary Boundary at El Kef. Marine Micropaleontology. 13: 239-263. gs

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

Premoli Silva, I. & Bolli, H. M. (1973). Late Cretaceous to Eocene planktonic foraminifera & stratigraphy of Leg 15 Sites in the Caribbean Sea. Initial Reports of the Deep Sea Drilling Project. 15: 449-547. gs

Smit, J. (1982). Extinction and Evolution of planktonic foraminifera after a major impact at the Cretaceous/Tertiary boundary. In, Silver, L. T. & Schultz, P. H. (eds) Geological Implications of Impacts of Large Asteroids and Comets on the Earth, Geological Society of America Special Paper 190. 329-352. gs


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

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