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Globorotaloides quadrocameratus Olsson et al. 2006 from: Pearson, P.N.Olsson, R.K.Hemleben, C.Huber, B.T.Berggren, W.A. (2006): Atlas of Eocene Planktonic Foraminifera. p. 1-513
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Anonymous: Unedited TaxonConcept data
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Species Globorotaloides quadrocameratus Olsson et al. 2006


Diagnosis / Definition:
Pearson et al. (2006):
DESCRIPTION. Type of wall: normal perforate, coarsely cancellate, spinose, ruber/sacculifer-type wall structure. Test morphology: Test very low trochospiral, lobulate in outline, chambers globu1ar; in spiral view 4- 41/2 globular, slightly embracing chambers in ultimate whorl, increasing rapidly in size, ultimate chamber may be reduced in size, sutures moderately depressed, straight; in umbilical view 4 dobular, slightly embracing chambers, increasing rapidly in size, ultimate chamber often reduced and directed towards and over the umbilicus, sutures moderately depressed, straight, umbilicus small and often covered by ultimate chamber, aperture umbilical in adult specimens, a low opening bordered by narrow thickened lip; in edge view chambers globular in shape, slightly embracing. Size: Maximum diameter of holotype 0.27 mm, minimum diameter 0.25 mm, maximum width 0.13 mm.
Discussion / Comments:
Pearson et al. (2006):
ETYMOL0GY.- Named after the four chambers in the final whorl, by which it is distinguished from Globorotaloides eovariabilis n. sp. DISTINGUISHING FEATURES.-Globorota-loides quadrocanzemtus n. sp. is characterized by its small, lobulate test, 4-41/2 chambers in the ultimate whorl, the umbilically directed ultimate chamber, and the sacculifer-type wall texture. DISCUSSION.- Globorotaloides quadrocameralus n. sp. appears to be the first species of Globorota1oides. It may have evolved in the basal Eocene from a parasubbotinid ancestor by flattening of the coil and developing a coarsely cancellate test, which is typical of the genus. The species is more typical of low latitude localities than later species of Globorotaloides, but also occurs in mid and higher latitudes. PHYLOGENETIC RELATIONSHIPS.- The origin of Globorotaloides quadrocameratus is unknown. It is possibly derived from Parasubbotina varianta with which it shares some morphologic features, principally in the sacculifer wall texture on parts of the test, rapidly enlarging chambers, and low trochospiral test. It also gave rise to Globorotaloides eovariablis n. sp. GEOGRAPHIC DISTRIBUTION.- This species is known from tropical and high latitude sites. STABLE ISOTOPE PALEOBIOL0GY.- No data available.
Systematics:

35
 Ordo Foraminiferida
  Superfamilia Globigerinaceae
   Familia Globigerinidae
    Genus Globorotaloides
     Species Globorotaloides quadrocameratus
Synonym list:
Pearson et al. (2006):
1975 Globigerina sp. . - McKeel & Lipps : p.90 pl. 3; fig 4a-c (partim; not pl. 2, fig. 2a-c) [upper Eocene, Alsea Siltstone, Coast Ranges, Oregon]
2006 Globorotaloides n sp. quadrocameratus Olsson et al.. - Pearson et al. : p.81 pl. 5.5; fig. 1-6
Specimen:
Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 521865
Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 521866
References:

McKeel,D.R.. and Lipps,J.H. (1975):
Eocene and Oligocene planktonic foraminifera from the central and southern Oregon coast range . Journal of Foraminiferal Research Vol. 5 p. 1-5

Pearson,P.N.; Olsson,R.K.; Hemleben,C.; Huber,B.T. and Berggren,W.A. (2006):
Atlas of Eocene Planktonic Foraminifera. p. 1-513
Anonymous: Unedited TaxonConcept data
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