Acarinina boudreauxi Fleisher 1974 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 Acarinina boudreauxi Fleisher 1974 |
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Diagnosis / Definition: |
Pearson et al. (2006):
DESCRIPTION.
Type of wall: Robust, heavily calcified, wall with
blocky fused muricae.
Test morphology: Subcircular planconvex test, coiled in a low trochospiral with 4 1/2-5 chambers in the final whorl; chambers radially compressed and appressed
with flat or slightly depressed sutures on a flat spiral side; aperture umbilical-extraumbilical, a low arch; ventral sutures straight, radial and depressed converging on a narrow, deep umbilicus; periphery subacute.
Size: Maximum diameter of holotype 0.28 mm; thickness 0.21 mm. |
Discussion / Comments: |
Pearson et al. (2006):
DISTINGUISHING FEATURES.-
Acarinina
boudreauxi is distinguished from A. interposita by the
much tighter coil and more compressed chambers, and
by having straight radial sutures on the umbilical side
and an anguloconical test. Acarinina boudreauxi differs
from A. punctocarinata by lacking a discontinuous
muricocarina and typically being smaller; it differs from
A. bullbrooki by its rounded profile and more slowly
expanding chambers and the $112-5 (as opposed to 4)
chambers in the final whorl.
DISCUSSION.-
This taxon has rarely been used, but
is nevertheless a distinctive form. Originally described
from Zones P9 to P1 1 in the Arabian Sea area, it has
recently been found at the same levels in Tanzanian drill
cores (PI. 9.5, Figs. 13-16). Acarinina boudreauxi is
clearly related to the A. bullbrooki group, particularly
the matthewsae morphotype described by Blow (1979)
(here considered conspecific with bullbrooki) but
appears lowerlearlier in the record, and provides a
possible evolutionary link for that group with lower
Eocene Acarinina pseudotopilensis.
PHYLOGENETIC RELATIONSHIPS.-
Possibly
evolved from Acarinina pseudotopilensis and was
ancestral to A. punctocarinata and A. bullbrooki.
STRATIGRAPHIC RANGE.-
Ranges from the lower Part of Zone E7 to within Zone E9.
GEOGRAPHIC DISTRIBUTION.-
Probably widespread; currently known only from the Indian Ocean.
STABLE ISOTOPE PALEOBIOL0GY.-
No data available. |
Systematics: |
35 Ordo Foraminiferida
Superfamilia Globigerinaceae
Familia Truncorotaloididae
Genus Acarinina
Species Acarinina boudreauxi
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Synonym list: |
Pearson et al. (2006):
1974 Acarinina boudreauxi Fleisher. - Fleisher : p.1112 pl. 1; fig. 2-5 [lower middle Eocene Zone P 11, DSDP Site 2 19, Arabian
Sea]
2006 Acarinina boudreauxi Fleisher. - Pearson et al. : p.273 pl. 9.5; fig. 9-16 (Pl. 9.5, Figs. 9-1 1: new SEMs of holotype of
Acarinina boudreauxi Fleisher)
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Specimen: |
Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM 211386
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References: |
Fleisher,R.L. (1974): Cenozoic planktonic foraminifera and biostratigraphy, Arabian Sea, Deep Sea Drilling Project, Leg 23A. In: Initial Reports of the Deep Sea Drilling Project Vol. 23 Eds: Whitmarsh, R.B.Weser, O.E.Ross, D.A. p. 1001-1072
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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