Acarinina nitida


Classification: pf_cenozoic -> muricate non-spinose -> Truncorotaloididae -> Acarinina -> Acarinina nitida
Sister taxa: << < A. alticonica, A. angulosa, A. aspensis, A. boudreauxi, A. bullbrooki, A. coalingensis, A. collactea, A. cuneicamerata, A. echinata, A. esnaensis, A. esnehensis, A. interposita, A. mcgowrani, A. mckannai, A. medizzai, A. nitida, A. pentacamerata, A. praetopilensis, A. primitiva, A. pseudosubsphaerica, A. pseudotopilensis, A. punctocarinata, A. quetra, A. rohri, A. sibaiyaensis, A. soldadoensis, A. strabocella, A. subsphaerica, A. topilensis, A. wilcoxensis,

Taxonomy

Citation: Acarinina nitida (Martin 1943)
Rank: Species
Basionym: Globigerina nitida
Synonyms:
Taxonomic discussion: This form is generally recognized to be a senior synonym of Acarinina acarinata (Subbotina), type species of the genus Acarinina (Stainforth et al., 1975; Luterbacher, 1975b; Berggren, 1977, who compared the holotype of nitida with topotypes of acarinata; Toumarkine
and Luterbacher, 1985). It is one of the earliest acarininids appearing together with A. subsphaerica at the base of Zone P4. Acarinina nitida represents an intermediate stage between the weakly muricate A. strabocella and the more strongly muricate upper Paleocene acarininids. Subbotina (1953) considered that acarinata ranged up to the base of her zone of conical globorotaliids (= P6a/b boundary of this work). Our observations agree more closely with Blow (1979), who indicated its LAD occurs in his Zone P5 or possibly lower P6.
The holotype of Acarinina intermedia Subbotina, 1953 (Plate 12: Figures 4-6), is a poorly preserved specimen with a missing ultimate chamber and an obscured umbilicus. The general morphology of this specimen shows four chambers in the ultimate whorl and heavily muricate umbilical shoulders suggesting a linkage to nitida. Acarinina nitida has also been previously identified under different names (see synonomy) by Weiss (1955), Bolli (1957a), and Loeblich and Tappan (1957a). [Olsson et al. 1999]

Catalog entries: Acarinina acarinata;
Acarinina intermedia;
Globigerina nitida;

Type images:

Short diagnosis: Compact, small, trochospiral, subcircular to subquadrate test with 4 (rarely 5) rounded, tightly packed, radially compressd and axially elongate chambers; early whorls raised above surface of last whorl; surface moderately muricate, particularly on umbilical side, with deep, funnel-shaped entrances to the pores.

NB The short diagnoses are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus. They have initially been copied from the diagnostic characters/distinguishing features sections of the Eocene and Paleocene Atlases, they will be edited as the site is developed.

Description


Diagnostic characters: Compact, small, trochospiral, subcircular to subquadrate test with 4 (rarely 5) rounded, tightly packed, radially compressd and axially elongate chambers; early whorls raised above surface of last whorl; surface moderately muricate, particularly on umbilical side, with deep, funnel-shaped entrances to the pores. [Olsson et al. 1999]

Character matrix

test outline:Circularcoiling axis:Lowchamber arrangement:Trochospiralumbilicus:Narrow
edge view:Equally biconvexumbilical or test sutures:Moderately depressedspiral sutures:Moderately depressedshell porosity:-
wall texture:Moderately muricateaperture:Umbilicalaperture border:N/Aaccessory apertures:None
periphery:N/Aumb chamber shape:Inflatedsp chbr shape:Inflatedperiph margin shape:Broadly rounded
umb depth:Deepdiameter mm:0.29width mm:-breadth mm:0.28
final-whorl chambers:4.0-4.0

Biogeography and Palaeobiology


Geographic distribution: This form is geographically widespread in (sub)tropical regions and has been reported from high southern latitudes on the Kerguelen Plateau (Huber, 1991b) and Maud Rise, Weddell Sea (Stott and Kennett, 1990) at 62° S and 65° S, respectively. [Olsson et al. 1999]
Aze et al. 2011 summary: Low to high southern latitudes; based on Olsson et al. (1999)

Isotope paleobiology: Acarinina nitida has ∂18O values similar to co-existing morozovellids, such as M. velascoensis and M. subbotinae, and shows a slight negative size-trend in ∂18O (D'Hondt et al., 1994). The ∂13C of A. nitida is much more positive than that of Subbotina and is similar to that of Morozovella (D'Hondt et al., 1994). [Olsson et al. 1999]
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts. Based on very heavy δ13C and relatively light δ18O. Sources cited by Aze et al. 2011 (appendix S3): D'hondt et al. (1994)

Phylogenetic relations: Acarinina nitida is related to unkeeled morozovellids with which the acarininids share a similar ornamentation consisting of deep funnel-shaped entrances to the pores, short, weakly developed muricae at the interpore ridges, deeply incised sutures, and a tendency toward slightly anguloconical chambers in the final whorl. Acarinina nitida is derived from A. strabocella from which it differs in having only four chambers in the final whorl, more involute coiling, and a more coarsely muricate surface texture. Bolli (1957a) and Blow (1979) suggested that Globorotalia whitei /A. acarinata, respectively, was the ancestor ofA. wilcoxensis and we concur. [Olsson et al. 1999]

Biostratigraphic distribution

Geological Range:
Notes: Zone P4a to lower Zone P4c. [Olsson et al. 1999]
Last occurrence (top): within P4c subzone (57.10-57.79Ma, top in Thanetian stage). Data source: Olsson et al. 1999
First occurrence (base): within P4a subzone (60.52-60.73Ma, base in Selandian 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. 48

References:

Olsson, R.K.; Hemleben, C.; Berggren, W.A. & Huber, B.T., (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Contributions to Paleobiology. Smithsonian Institution Press, Washington, DC, 1-252 pp.


Acarinina nitida compiled by the pforams@mikrotax project team viewed: 29-5-2017

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