Morozovella apanthesma


Classification: pf_cenozoic -> muricate non-spinose -> Truncorotaloididae -> Morozovella -> Morozovella apanthesma
Sister taxa: M. caucasica, M. crater, M. aragonensis, M. lensiformis, M. subbotinae, M. marginodentata, M. formosa, M. gracilis, M. aequa, M. apanthesma, M. angulata, M. praeangulata, M. edgari, M. allisonensis, M. velascoensis, M. acuta, M. occlusa, M. pasionensis, M. acutispira, M. conicotruncata, M. sp.,

Taxonomy

Citation: Morozovella apanthesma (Loeblich and Tappan 1957)
Rank: Species
Basionym: Globorotalia apanthesma
Synonyms:
Taxonomic discussion: Blow (1979) drew attention to an important distinction within this plexus: apanthesma exhibits the essentially quadrate chamber pattern of the related (and descendant) aequa in the early whorls, whereas angulata (and related forms) retains the more "vorticiform," strongly recurved, early whorl pattern. In view of these, and other pertinent observations based on personal observations of type material (Blow,
1979), it is strange that he presented, almost as an afterthought, only a single, spiral view of a form assigned to apanthesma from (his) Zone P7 (= Zone P6 this paper) whose affinities are somewhat hard to evaluate. Earlier this species was considered a junior synonym of M. conicotruncata (Subbotina) by Luterbacher (1964) and of M. angulata (White) by Berggren (1977).
Illustrated on Plate 11: Figures 10-12 is a specimen from the collections of Shutskaya (no. 645) in VNIGRI (St. Petersburg) that is probably referable to M. apanthesma. Although the slide containing this specimen is labeled as Globorotalia angulata var. kubanensis Shutskaya, the illustration of the holotype resembles M. conicotruncata (Subbotina). Because the holotype in Moscow is lost, the identity of this taxon cannot be determined. Further confusing the taxonomic status of Shutskaya's taxon is the other specimen from the same slide (no. 645) illustrated on Plate 11: Figures 13-15. This specimen is probably referable to M. acutispira. [Olsson et al. 1999]

Catalog entries: Globorotalia apanthesma;

Type images:

Distinguishing features: Planoconvex, umbilicoconvex, test with lobulate, weakly muricocarinate periphery; 4-5 chambers in last whorl, inflated to subangular on umbilical side, moderately convex, triangular (lunate) in edge view; intercameral sutures on umbilical side depressed, radially curved and slightly depressed on spiral side; umbilical side distinctly muricate, coarsely perforate on spiral side; umbilicus relatively narrow, deep; aperture an interiomarginal, umbilical-extraumbilical arch with narrow, continuous intraperiumbilical lip.

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: Planoconvex, umbilicoconvex, test with lobulate, weakly muricocarinate periphery; 4-5 chambers in last whorl, inflated to subangular on umbilical side, moderately convex, triangular (lunate) in edge view; intercameral sutures on umbilical side depressed, radially curved and slightly depressed on spiral side; umbilical side distinctly muricate, coarsely perforate on spiral side; umbilicus relatively narrow, deep; aperture an interiomarginal, umbilical-extraumbilical arch with narrow, continuous intraperiumbilical lip. [Olsson et al. 1999]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Planoconvexaperture:Umb.-extraumbilical
umb chamber shape:Subtriangularcoiling axis:Highperiphery:Muricocarinateaperture border:Thin lip
sp chbr shape:Crescenticumbilicus:Wideperiph margin shape:Subangularaccessory apertures:None
umbilical or test sutures:Strongly depressedumb depth:Deepwall texture:Spinoseshell porosity:Macroperforate: >2.5µm
spiral sutures:Weakly depresseddiameter mm:0.23 - 0.45width mm:-breadth mm:0.15 - 0.33
final-whorl chambers:4.0-5.0

Biogeography and Palaeobiology


Geographic distribution: Northern middle latitudes to the Southern Ocean. [Olsson et al. 1999]
Aze et al. 2011 summary: Northern middle latitudes to the Southern Ocean; based on Olsson et al. (1999)

Isotope paleobiology: Limited isotopic data suggest M. apanthesma is similar in ∂18O and ∂13C to other morozovellids and has a more positive ∂13C and more negative 5lsO than coexisiting Globanomalina and Subbotina (Lu and Keller, 1996; Berggren and Norris, 1997). [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): Lu & Keller (1996); Berggren & Norris (1997)

Phylogenetic relations: Morozovella apanthesma and its descendants, M. aequa and M. subbotinae, differ from the M. angulata-M. velascoensis group in possessing a relatively even distribution of fine muricae (pustules) over the surface of the test in contrast to the development of muricae-free surfaces between the murcorcarina and adumbilical ridges in the M velascoensis plexus. Morozovella apanthesma shares characteristics intermediate between M. praeangulata (its antecedent) and M. aequa (its descendant). The former is generally somewhat smaller (contra Loeblich and Tappan, 1957a; see also Jenkins, 1971), with more subdued muricate wall texture and more strongly recurved chambers when seen from the spiral surface. Compared to its ancestor, M. aequa exhibits a reduced number of chambers and a more anguloconical test. [Olsson et al. 1999]

Most likely ancestor: Morozovella angulata - at confidence level 4 (out of 5). Data source: Olsson et al. (1999) f5a.

Biostratigraphic distribution

Geological Range:
Notes: Zone P3b to Zone P4c. [Olsson et al. 1999]
Last occurrence (top): at top of P4c subzone (100% up, 57.1Ma, in Thanetian stage). Data source: Olsson et al. (1999) f5a
First occurrence (base): at base of P3b subzone (0% up, 61.3Ma, in Selandian stage). Data source: Olsson et al. (1999) f5a

Plot of occurrence data:

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 59

References:

Berggren, W.A., (1977). Atlas of Palaeogene Planktonic Foraminifera: some Species of the Genera Subbotina, Planorotalites, Morozovella, Acarinina and Truncorotaloides. In: Ramsay, A.T.S. (Editor), Oceanic Micropaleontology. Academic Press, London, pp. 205-300.

Blow, W.H., (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea), 2. E. J. Brill, Leiden, 1413 pp.

Loeblich, A.R., Jr. & Tappan, H., (1957). Planktonic foraminifera of Paleocene and early Eocene Age from the Gulf and Atlantic coastal plains. In: Loeblich, A.R., Jr. et al. (Editors), Studies in Foraminifera, U.S. National Museum Bulletin 215. U.S. Government Printing Office, Washington, D.C., pp. 173-198.

Luterbacher, H.P., (1964). Studies in some Globorotalia from the Paleocene and Lower Eocene of the Central Apennines. Eclogae Geologicae Helvetiae, 57: 631-730.

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

Ouda, K. & Aubry, M.-P., (2003). The Upper Paleocene- Lower Eocene of the Upper Nile Valley: Part 1: Stratigraphy. Micropaleontology, 49(Supplement 1): 212.


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Morozovella apanthesma compiled by the pforams@mikrotax project team viewed: 22-7-2018

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