Turborotalia frontosa

Classification: pf_cenozoic -> smooth non-spinose -> Hedbergellidae -> Turborotalia -> Turborotalia frontosa
Sister taxa: T. cunialensis, T. cocoaensis, T. cerroazulensis, T. pomeroli, T. frontosa, T. ampliapertura, T. increbescens, T. altispiroides, T. possagnoensis, T. sp.,


Citation: Turborotalia frontosa Subbotina 1953
Rank: Species
Basionym: Globigerina frontosa
Taxonomic discussion: Subbotina (1953) illustrated a variable suite of specimens from the Kuban river section, demonstrating a broad species concept. The holotype (figured by SEM for the first time in Pl. 15.5, Figs. 1-3) is a slightly kummerform specimen. Unaware of Subbotina’s work, Bolli (1957c) erected the species boweri using a specimen (also figured by SEM for the first time in Plate 15.5, Figs. 5-7) that is very similar to one of Subbotina’s paratypes (her pl. 12, fig. 4a-c). Many authors (e.g., Dieci, 1965; Toumarkine and Bolli, 1970, and Stainforth and others, 1975) have considered the two as synonymous, but some (e.g., Blow, 1979, p. 1264) have distinguished the two taxa on the basis of the supposedly tighter coiling of boweri and the fact that the latter supposedly has three rather than three and a half chambers in the final whorl. These apparent differences can be explained, however, by the reduced size of the final chamber in Subbotina’s holotype.
The distinctive wall texture of this species, and its ontogenetic development, are discussed in detail by Hemleben and Olsson (Chapter 4, this volume). [Pearson et al. 2006]

Catalog entries: Globigerina ayalai;
Globigerina frontosa;

Type images:

Short diagnosis: vs Subbotina distinguished by pustulose wall texture, high arched aperture and slightly compressed final chamber. Also has a strong bias in coiling direction. Chambers more globular than in other Turborotalia species.

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.


Diagnostic characters: Turborotalia frontosa is distinguished from all species of Subbotina by its pustulose wall texture, high arched aperture and slightly compressed final chamber, which foreshadows later species of Turborotalia. It also has a strong bias in coiling direction. It is distinguished from T. possagnoensis and other species of Turborotalia by the relatively globular chamber shape and globigeriniform morphology in the adult stage. [Pearson et al. 2006]

Wall type: Weakly cancellate with raised cylindrical pustules on the early chambers, becoming smoother on final chamber; tendency to defoliate. [Pearson et al. 2006]

Test morphology: Trochospiral, globorotaliform in early chambers, globigerinform in last whorl, which comprises 3 to 3½ chambers; chambers inflated, radially compressed, increasing rapidly in size, with final chamber making up about half of test (unless kummerform, as holotype); dorsal sutures straight, moderately depressed; aperture a broad, high arch in intra-extraumbilical position, sometimes extending almost to periphery, fringed in most specimens by a pronounced imperforate lip of constant thickness; umbilicus very narrow; ventral sutures slightly curved, depressed; strong tendency for dextral coiling. [Pearson et al. 2006]

Size: Holotype length 0.44 mm, breadth 0.31 mm [Pearson et al. 2006]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical
umb chamber shape:Globularcoiling axis:Lowperiphery:N/Aaperture border:Thin lip
sp chbr shape:Globularumbilicus:Narrowperiph margin shape:Broadly roundedaccessory apertures:None
umbilical or test sutures:Moderately depressedumb depth:Shallowwall texture:Cancellateshell porosity:
spiral sutures:Moderately depresseddiameter mm:0.44width mm:breadth mm:0.31
final-whorl chambers:3.0-3.5

Biogeography and Palaeobiology

Geographic distribution: Cosmopolitan. [Pearson et al. 2006]
Aze et al. 2011 summary: Cosmopolitan; based on Pearson et al. (2006)

Isotope paleobiology: This species was a relatively deep-dwelling form according to Boersma and others (1987; recorded as T. boweri) and Pearson and others (1993, 2001). [Pearson et al. 2006]
Aze et al. 2011 ecogroup 4 - Open ocean sub-thermocline. Based on very light δ13C and very heavy δ18O. Sources cited by Aze et al. 2011 (appendix S3): Boersma et al. (1987); Pearson (1993); Pearson et al. (2001a)

Phylogenetic relations: Evolved from Globanomalina australiformis, according to Hemleben and Olsson (Chapter 4, this volume). [Pearson et al. 2006]

Most likely ancestor: Globanomalina australiformis - at confidence level 4 (out of 5). Data source: Pearson et al. (2006), fig 15.1.

Biostratigraphic distribution

Geological Range:
Notes: Lower to middle Eocene, from within Zone E7 to upper Zone E11
(Toumarkine and Bolli, 1970; Toumarkine and Luterbacher, 1985). [Pearson et al. 2006]
The FAD of Turborotalia frontosa marks the base of zone E7b / top of E7a (Wade et al. 2011)
Last occurrence (top): in upper part of E11 zone (80% up, 40.7Ma, in Bartonian stage). Data source: Pearson et al. (2006), fig. 15.1
First occurrence (base): at base of E7b subzone (0% up, 48.3Ma, in Ypresian stage). Data source: zonal marker (Wade et al. 2011)

Plot of occurrence data:

Primary source for this page: Pearson et al. 2006 - Atlas of Eocene Planktonic Foraminifera, chapter 15, p. 452


Bermudez, P.J., (1961). Contribucion al estudio de las Globigerinidea de la region Caribe-Antillana (Paleoceno-Reciente). Mem. III Congreso Geol. Venez. Editorial Sucre, Caracas, 1119-1393 pp.

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, 1413 pp.

Bolli, H.M., (1957). Planktonic foraminifera from the Eocene Navet and San Fernando formations of Trinidad. 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. 155-172.

Dieci 1965 [sorry, not in our bibliography yet]

Jenkins, D.G., (1971). New Zealand Cenozoic Planktonic Foraminifera. New Zealand Geological Survey, Paleontological Bulletin, 42: 1-278.

Krasheninnikov, V.A. & Basov, I.A., (1983). Stratigraphy of Cretaceous sediments of the Falkland Plateau based on planktonic foraminifers, Deep Sea Drilling Project, Leg 71. In: Ludwig, W.J., Krasheninnikov, V.A. and al., e. (Editors), Initial Reports of the Deep Sea Drilling Project. U.S. Government Printing Office, Washington, D.C., pp. 789-820.

Pearson, P.N.; Shackleton, N.J. & Hall, M.A., (1993). Stable isotope paleoecology of middle Eocene planktonic foraminifera and multi-species isotope stratigraphy, DSDP Site 523, South Atlantic. Journal of Foraminiferal Research, 23: 123-140.

Pearson, P.N.; Premec-Fucek, V. & Premoli Silva, I., (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene Turborotalia. In: Pearson, P.N. et al. (Editors), Atlas of Eocene Planktonic Foraminifera, Cushman Foundation Special Publication 41. Allen Press, Lawrence, Kansas, pp. 433-460.

Poag, C.W. & Commeau, J.A., (1995). Paleocene to middle Miocene planktic foraminifera of the southwestern Salisbury Embayment, Virginia and Maryland: Biostratigraphy, allostratigraphy, and sequence stratigraphy. Journal of Foraminiferal Research, 25: 134-155.

Poore, R.Z. & Brabb, E.E., (1977). Eocene and Oligocene planktonic foraminifera from the Upper Butano sandstone and type San Lorenzo formation, Santa Cruz Mountains, California. Journal of Foraminiferal Research, 7(4): 249-272.

Poore, R.Z. & Bybell, L.M., (1988). Eocene to Miocene biostratigraphy of New Jersey Core ACGS #4: Implications for regional stratigraphy. U.S. Geological Survey Bulletin 1829: 1-41.

Snyder, S.W. & Waters, V.J., (1985). Cenozoic planktonic foraminiferal biostratigraphy of the Goban Spur Region, Deep Sea Drilling Project Leg 80. Initial Reports of the Deep Sea Drilling Project, 80: 439-472.

Stainforth, R.M.; Lamb, J.L.; Luterbacher, H.; Beard, J.H. & Jeffords, R.M., (1975). Cenozoic planktonic foraminiferal zonation and characteristics of index forms. The University of Kansas Paleontological Contributions, 62: 1-425.

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

Toumarkine, M. & Bolli, H.M., (1970). Evolution de Globorotalia cerroazulensis (Cole) dans l'Eocene moyen et superieur de Possagno (Italie). Revue de Micropaleontologie, 13(3): 131-145.

Toumarkine, M. & Luterbacher, H., (1985). Paleocene and Eocene planktic foraminifera. Plankton Stratigraphy. Cambridge Univ. Press, Cambridge, 87-154 pp.

Toumarkine, M., (1975). Middle and Late Eocene planktonic foraminifera from the northwestern Pacific Ocean: Leg 32 of the Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project, 32: 735-751.

Toumarkine, M., (1978). Planktonic foraminiferal biostratigraphy of the Paleogene of Sites 360 to 364 and the Neogene of Sites 362A, 363 and 364 Leg 40,. Initial Reports of the Deep Sea Drilling Project, 40: 679-721.

Wade, B.S.; Pearson, P.N.; Berggren, W.A. & Pälike, H., (2011). Review and revision of Cenozoic tropical planktonic foraminiferal biostratigraphy and calibration to the geomagnetic polarity and astronomical time scale. Earth-Science Reviews, 104: 111-142.


Turborotalia frontosa compiled by the pforams@mikrotax project team viewed: 25-11-2017

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