pforams@mikrotax - Parvularugoglobigerina extensa

Citation: Parvularugoglobigerina extensa (Blow 1979)

Basionym: Eoglobigerina? extensa

Synonyms:

Woodringina hornerstownensis group, Premoli Silva and Bolli, 1973:538, 540, pl. 6: fig. 10, pl. 7: fig. 1 [Globigerina eugubina Zone, DSDP Site 150/10/2: 78-50 cm; Caribbean Sea]. [Not Olsson, I960.]
Eoglobigerina? extensa Blow, 1979:1220, pl. 69: fig. 7 [Zone Pl, DSDP Hole 47.2/11/3: 0-5 cm], pl. 74: figs. 1, 2 [Zone Pl, DSDP Hole 47.2/11/3: 148-150 cm; Shatsky Rise, northwestern Pacific Ocean].
Eoglobigerina? fodina Blow, 1979:1221, pl. 57: figs. 5, 6 [Zone Pa, DSDP Hole 47.2/11/5: 148-150 cm; Shatsky Rise, northwestern Pacific Ocean].
Globigerina minutula Luterbacher and Premoli Silva.—Smit, 1982:338, pl. 3: figs. 3-6 [Zone Pa, Gredero, southeastern Spain]. [Not Luterbacher and Premoli Silva, 1964.]
Globoconusa conusa (Khalilov).—Keller, 1988:257, pl. 3: figs. 12-14 [Zone POb, El Kef, Tunisia]; 1989:319: figs. 3, 9-11 [Zone Pa, Brazos River, Texas]. [Not Khalilov, 1956.]
Parvularugoglobigerina morphotype 1, D'Hondt and Keller, 1991:93. pl. 3: figs. 3-5, 7-10 [figs. 3, 4, 7-10, Zone Pa, DSDP Site 577/12/5: 115-117 cm; Shatsky Rise, northwestern Pacific Ocean; fig. 5, lower Danian, Brazos River, Texas].
Parvularugoglobigerina morphotype 2, D'Hondt and Keller, 1991:96, pl. 41: figs. 1, 2 [Zone Pa, DSDP Site 577/12/5: 115-117 cm; Shatsky Rise, northwetern Pacific Ocean].
Parvularugoglobigerina aff. eugubina (Luterbacher and Premoli Silva).—Liu and Olsson, 1992:345, pl. 2: figs. 8-11 [Zone Pa, Pine Barren Mbr., Clayton Fm., Millers Ferry, Alabama], [Olsson et al. 1999]

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]

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.

Description

Typically characterized by 2½ whorls, each composed of 3½ to 4 inflated subglobular chambers, increasing slowly in size. The aperture is centrally located, umbilical to extraumbilical, marked by a distinct lip, often elongate, and often asymmetrically oriented. The test wall is microperforate. Despite the original description, the pustules are not bases of normal spines but guembelitriid pustules that are typically either perforated by pores (pore-mounds) or peripherally associated with pores. [Olsson et al. 1999]

Biogeography and Palaeobiology

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

No data available. [Olsson et al. 1999]

This species evolved from Guembelitria cretacea. [Olsson et al. 1999]

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

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 85

References:

Blow, W. H. (1979). 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. E. J. Brill, Leiden. 2: 1-1413. gs

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

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

Liu, C. & Olsson, R. K. (1992). 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. Journal of Foraminiferal Research. 22: 328-346. gs

Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. 1-252. Smithsonian Institution Press, Washington, DC. (85): 1-252. gs

Premoli Silva, I. & Bolli, H. M. (1973). 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. Initial Reports of the Deep Sea Drilling Project. 15: 449-547. gs

Smit, J. (1982). 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. 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

test outline:	Lobate	chamber arrangement:	Trochospiral	edge view:	Equally biconvex	aperture:	Umbilical
sp chamber shape:	Inflated	coiling axis:	Moderate-high	periphery:	N/A	aperture border:	Thick porticus
umb chbr shape:	Inflated	umbilicus:	Absent	periph margin shape:	Broadly rounded	accessory apertures:	None
spiral sutures:	Strongly depressed	umb depth:	N/A	wall texture:	Pore mounds	shell porosity:	Microperforate: <1µm
umbilical or test sutures:	Strongly depressed	final-whorl chambers:	4-4	N.B. These characters are used for advanced search. N/A - not applicable

Parvularugoglobigerina extensa

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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