pforams@mikrotax - Morozovella conicotruncata pforams@mikrotax - Morozovella conicotruncata

Morozovella conicotruncata

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


Citation: Morozovella conicotruncata (Subbotina 1947)
taxonomic rank: Species
Basionym: Globorotalia conicotruncata
Taxonomic discussion: This is a distinct middle Paleocene planoconvex morozovellid species characterized by 5-7 equidimensional chambers in the last whorl. Our studies support Blow's (1979) observation that this form appears virtually simultaneously with typical angulata-types (cf. Bolli, 1957a); however, we do not agree with the extended range given this taxon by Blow (1979) of mid-Zone P3 through Zone P4, extending possibly into Zone P5. Our studies support, rather, the range given by Bolli (1957a) of its extension into the lower part of the Globorotalia pseudomenardii Zone. [Olsson et al. 1999]

Catalog entries: Globorotalia conicotruncata, Globorotalia angulata abundocamerata

Type images:

Distinguishing features:
Parent taxon (Morozovella): Test typically plano-convex, chambers strongly anguloconical.
Wall strongly pustulose (muricate) on parts of spire and umbilicus. Most species with muricocarina.

This taxon: Like M. angulata (White) but test more planoconvex; umbilucs more open; and with a low rate of chamber enlargement, and so (5-7) equidimensional chambers in the final whorl.

NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus.
They are being edited as the site is developed and comments on them are especially welcome.


Character matrix
test outline:Lobatechamber arrangement:Trochospiraledge view:Planoconvexaperture:Umbilical-extraumbilical
sp chamber shape:Crescenticcoiling axis:Moderate-highperiphery:Muricocarinateaperture border:N/A
umb chbr shape:Subtriangularumbilicus:Wideperiph margin shape:Subangularaccessory apertures:None
spiral sutures:Weakly depressedumb depth:Deepwall texture:Moderately pustuloseshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:4.5-5.5 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

As with its closely related sister taxon angulata, this form has a predominantly tropical to temperate distribution (< 45° N and S) and has not been reliably reported from high northern or southern (subantarctic) latitudes. It is a common and distinct form in our material and is observed to grade into M. velascoensis in Subzone P3b. [Olsson et al. 1999]
Aze et al. 2011 summary: Low latitudes; based on Olsson et al. (1999)

Isotope paleobiology
Morozovella conicotruncata has δ13C similar to M. angulata and more positive than Subbotina and Globanomalina (Boersma and Premoli Silva, 1983; Berggren and Norris, 1997). The δ18O of M. conicotruncata is slightly lighter than M. angulata in samples from DSDP Site 384 (Berggren and Norris, 1997) and is distinctly lighter than coexisting Globanomalina and Subbotina (Boersma and Premoli Silva, 1983; 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 _13C and relatively light _18O. Sources cited by Aze et al. 2011 (appendix S3): Boersma & Premoli Silva (1983); Berggren & Norris (1997)

Phylogenetic relations
This morphospecies evolved from Morozovella angulata (White) in the lower part of Zone P3 by the development of a distinctly planoconvex test, a more open umbilicus than M. angulata, and a characteristic low rate of chamber enlargement, which results in equidimensional chambers throughout the final whorl. [Olsson et al. 1999]

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

Biostratigraphic distribution

Geological Range:
Notes: Zone P3 to lower Zone P4. [Olsson et al. 1999]
Last occurrence (top): at top of P4 zone (100% up, 57.1Ma, in Thanetian stage). Data source: Olsson et al. (1999) f5a
First occurrence (base): near base of P3 zone (10% up, 62.1Ma, in Danian 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. 60


Berggren, W. A. (1971c). Paleogene planktonic foraminiferal faunas on Legs I-IV (Atlantic Ocean) JOIDES Deep Sea Drilling Program: a synthesis. In, Farinacci, A. (ed.) Proceedings of the Second Planktonic Conference, Roma 1970. Edizioni Tecnoscienza, Rome 57-77. gs

Blow, W. H. (1979). The Cainozoic Globigerinida: A study of the morphology, taxonomy, evolutionary relationships and stratigraphical distribution of some Globigerinida (mainly Globigerinacea). E. J. Brill, Leiden. 2: 1-1413. gs

Bolli, H. M. & Cita, M. B. (1960). Globigerine e Globorotalie del Paleocene di Paderno d'Adda (Italia). Rivista Italiana di Paleontologia e Stratigrafia. LXVI(3): 1-42. gs

Bolli, H. M. (1957d). The genera Globigerina and Globorotalia in the Paleocene-Lower Eocene Lizard Springs Formation of Trinidad. In, Loeblich, A. R. , Jr., Tappan, H., Beckmann, J. P., Bolli, H. M., Montanaro Gallitelli, E. & Troelsen, J. C. (eds) Studies in Foraminifera. U.S. National Museum Bulletin . 215: 61-82. gs

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

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

Postuma, J. A. (1971). Manual of planktonic foraminifera. Elsevier for Shell Group, The Hague. 1-406. gs

Shutskaya, E. K. (1956). Стратиграфия нижних горизонтов палеогена Центрального Предкавказья по фораминиферам - Stratigraphy of the lower horizons of the Paleogene of the central Precaucasus according to the foraminifera. Maden Tetkik ve Arcana Enstitusu Yayinharindam (Mining Research and Exploration, Institute of Turkey Publ.).. 71(164): 3-119. gs

Shutskaya, E. K. (1970b). Stratigrafiya, foraminifery i paleogeografiya nizhnego paleogena Kryma, predkavkaz'ya i zapadnoi chadsti srednei azii [Stratigraphy, Foraminifera and Paleogeography of the Lower Paleogene in the Crimea, Precaucasus and the Western Part of Central Asia]. Trudy Vsesoyuznego Neftyanogo Nauchno-Issledovatel'skogo Geologo-Razvedochnogo Instituta (VNIGRI). 70(1): 256-. gs

Subbotina, N. N. (1947). Danian and Paleogene foraminifera of the northern Caucasus. Trudy VNIGRI Mikrofauna USSR. 1947: 39-160. gs O

Subbotina, N. N. (1953). Foraminiferes fossiles d'URSS Globigerinidae, Globorotaliidae, Hantkeninidae. Bureau de Recherches Geologiques et Minieres. 2239: 1-144. gs


Morozovella conicotruncata compiled by the pforams@mikrotax project team viewed: 20-6-2024

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