Parasubbotina pseudowilsoni Olsson & Pearson 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 | . |
Notice: This catalogue page may contain unedited data.
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Species Parasubbotina pseudowilsoni Olsson & Pearson 2006 |
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| Diagnosis / Definition: |
Pearson et al. (2006):
DESCRIPTION.
Type of wall: Cancellate, normal perforate,
spinose, ruber-sacculifer type wall texture.
Test morphology: Test small, very low
trochospiral, globular, lobulate in outline, chambers
globular; in spiral view 5 globular, moderately embracing
chambers in ultimate whorl, increasing moderately in
size, sutures moderately depressed, ultimate chamber
usually slightly reduced in size relative to the penultimate
chamber; in umbilical view 5 globular, moderately
embracing chambers, increasing moderately in size,
sutures moderately depressed, straight; umbilicus a
moderate sized opening, enclosed by surrounding
chambers; aperture umbilical to somewhat
extraumbilical, bordered by a continuous lip, which
varies in its width from narrow to broad; in edge view
chambers globular in shape, moderately embracing,
aperture visible as a low arch, bordered by a narrow to
broad lip.
Size: Maximum diameter of holotype 0.25 mm,
thickness 0.15 mm. |
| Discussion / Comments: |
Pearson et al. (2006):
ETYMOLOGY.-
Named after its resemblance to
Globigerina wilsoni Cole which is referred to
Globoturborotalita carcoselleen.sis in this work.
DISTINGUISHING FEATURES.-
Parasubbotina pseudowilsoni n. sp. is a small form with a compact, very low trochospiral test that typically has 5 chambers in the final whorl, as seen in dorsal view. Parasubbotina
varianta is larger and has a more lobulate test with 4 chambers in the ultimate whorl.
DISCUSSION.-
Toumarkine and Luterbacher (1985)
reillustrated the line drawing of the holotype of
Globigerina wilsoni along with three SEM images they
identified to that species from the type Guayabal
Formation, from where G. wilsoni was originally
described. New SEM images of the holotype of G.
wilsoni (Chapter 6, P1. 6.23, Figs. 15-17), although
poorly preserved, show that it differs from the hypotypes
illustrated by Toumarkine and Luterbacher in that the
ultimate chamber is more flattened and extends towards
and over the umbilicus. In this respect, the holotype
appears much more like Globorotaloides carcoselleensis
Toumarkine and Bolli (=Turborotalita carcoselleensis),
which is common in the Guayabal Formation. However,
the poor state of preservation does not allow an accurate
identification, and we place wilsoni in questionable
synonymy with carcoselleensis. Parasubbotina
pseudowilsoni n. sp. is also a common form in the
Guayabal Formation and occurs as a relatively inconspicuous component in many other Eocene
localities.
PHYLOGENETIC RELATIONSHIPS.-
Parasubbotina pseudowilsoni n. sp. appears to have
developed hom P. varianta (Subbotina) in the uppermost
Lower Eocene.
GEOGRAPHIC DISTRIBUTION.-
Cosmopolitan in low to mid latitudes.
STABLE TSOTOPIC PALEOBIOL0GY.-
No data available. |
| Systematics: |
35
Ordo Foraminiferida
Superfamilia Globigerinaceae
Familia Globigerinidae
Genus Parasubbotina
Species Parasubbotina pseudowilsoni
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| Synonym list: |
Pearson et al. (2006):
1985 Turborotalia wilsoni Cole. - Toumarkine & Luterbacher : p.125 fig. 27: 2-3 [middle Eocene Zone E10/11,
Guayabal Fm., type locality, Tampico, Mexico]. [Not Cole,
1927.]
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| Specimen: |
Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 521869
Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 521870
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| References: |
Toumarkine,M. and Luterbacher,H.P. (1985):
Paleocene and Eocene Planktic Foraminifera.
In: Plankton Stratigraphy p. 87-154
Pearson,P.N.; Olsson,R.K.; Hemleben,C.; Huber,B.T. and Berggren,W.A. (2006):
Atlas of Eocene Planktonic Foraminifera. p. 1-513
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