Trilobatus trilobus

Classification: pf_cenozoic -> Globigerinidae -> Trilobatus -> Trilobatus trilobus
Sister taxa: T. sacculifer, T. quadrilobatus, T. immaturus, T. trilobus ⟩⟨ T. bisphericus, T. sicanus ⟩⟨ T. altospiralis, T. praeimmaturus, T. primordius, T. subsacculifer, T. sp.


Citation: Trilobatus trilobus (Reuss 1850)
Rank: Species
Basionym: Globigerina triloba Reuss 1850
Taxonomic discussion:

There is little consensus on how many species to recognise within this group. In the modern ocean the sacculifer, quadrilobatus, immaturus and trilobus test morphotypes are all produced by the same species (Andre et al. 013), and so are no longer separated by biologists. They are, however, used by palaeontologists including Spezzaferri et al. (2018) and Poole & Wade (2019) [editor's comment - JRY 2018]

Originally described as Globigerina triloba, this form was attributed for the first time to the genus Globigerinoides by Coryell and Mossmann (1942). The evolution of T. trilobus to Orbulina was proposed by Cushman and Dorsey (1940) and successively Blow (1956), Jenkins (1968) and Pearson and Chaisson (1997) described the evolutionary steps in detail. See T. immaturus for the discussion of previously proposed phylogenetic relationships (e.g. Kennett and Srinivasan, 1983).

All specimens of T. trilobus identified by Reuss and stored at the Natural History Museum of Vienna do have a number but the catalogue to the numbers is missing. Since it was not possible to identify the holotype from the Reuss’ drawings, Rögl (2012) designated a neotype.

At the beginning of its range in Zone M1 this species displays a more ovate profile than younger Miocene specimens, when it becomes more compact, and rectangular. Based on data from the fossil record, and the molecular clock, Aurahs and others (2011) suggested a phylogenetic relationship between T. primordius and T. trilobus.

[Spezzaferri et al. 2018]

Catalog entries: Globigerina triloba, Globigerinoides trilobus bullatus

Type images:

Distinguishing features: 3 globular chambers in the last whorl, slit-like aperture

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.


Wall type: Normal perforate, spinose, sacculifer-type wall. [Spezzaferri et al. 2018]

Morphology: Low trochospiral, consisting of about 3 whorls, subrectangular, compact to slightly lobate in outline; 3 subspherical chambers in the last whorl, increasing rapidly in size. The embracing last chamber generally comprises half of the test. Sutures depressed, straight on both sides, umbilicus concealed. Primary aperture an umbilical-extraumbilical elongated slit. Supplementary aperture is an irregular slit along the spiral suture. [Spezzaferri et al. 2018]

Size: Neotype maximum length 0.35 mm and maximum width 0.26 mm. [Spezzaferri et al. 2018]

Character matrix

test outline:Lobatechamber arrangement:Trochospiraledge view:Equally biconvexaperture:Umbilical
sp chamber shape:Globularcoiling axis:Low-moderateperiphery:N/Aaperture border:-
umb chbr shape:Globularumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:Sutural
spiral sutures:Moderately depressedumb depth:Deepwall texture:Cancellateshell porosity:Macroperforate: >2.5µm
umbilical or test sutures:Strongly depressedfinal-whorl chambers:3.0-3.0 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution: Very abundant in the tropics (Bé and Tolderlund, 1971) but present also at middle latitudes. [Spezzaferri et al. 2018]

Isotope paleobiology: Pearson and others (1997) indicate for this species mixed-layer habitat with symbiotic associations. Experiments summarized by Hemleben and others (1989) identified for T. trilobus a temperature tolerance of 14–31°C. [Spezzaferri et al. 2018]

Phylogenetic relations: Trilobatus trilobus evolved from T. immaturus in Subzone M1a. [Spezzaferri et al. 2018]

Most likely ancestor: Trilobatus immaturus - at confidence level 3 (out of 5). Data source: Spezzaferri et al. 2018.
Likely descendants: Trilobatus bisphericus; Trilobatus subsacculifer;

Biostratigraphic distribution

Geological Range:
Notes: Lower Miocene upper part of Subzone M1a (Spezzaferri, 1994) to Recent. The base occurrence of T. trilobus s.l. is calibrated to 23.73 Ma (Wade and others, 2011), however, it is here retained for T. immaturus (see stratigraphic range of T. immaturus, this chapter). [Spezzaferri et al. 2018]
Last occurrence (top): Extant Data source: Spezzaferri et al. 2018
First occurrence (base): within M1a subzone (22.44-22.96Ma, base in Aquitanian stage). Data source: Spezzaferri et al. 2018

Plot of occurrence data:

Primary source for this page: Spezzaferri et al. 2018 - Olig Atlas chap.9 p.300; Kennett & Srinivasan 1983 p 62


Aurahs, R., Treis, Y., Darling, K. & Kucera, M. (2011). A revised taxonomic and phylogenetic concept for the planktonic foraminifer species Globigerinoides ruber based on molecular and morphometric evidence. Marine Micropaleontology. 79: 1-14. gs

Bé, A. W. H. & Tolderlund, D. S. (1971). Distribution and ecology of living planktonic foraminifera in surface waters of the Atlantic and Indian Oceans. In, Funnell, B. M. & Riedel, W. R. (eds) Micropaleontology of Oceans. Cambridge Univ. Press, Cambridge, UK 105-149. gs

Blow, W. H. (1956). Origin and evolution of the foraminiferal genus Orbulina d'Orbigny. Micropaleontology. 2(1): 57-70. gs

Coryell, H. H. & Mossmann, R. W. (1942). Foraminifera from the Charco Azul Formation, Pliocene, of Panama. Journal of Paleontology. 16: 233-246. gs

Cushman, J. A. & Dorsey, A. L. (1940). Some Notes on the Genus Candorbulina. Contributions from the Cushman Laboratory for Foraminiferal Research. 16(2): 40-42. gs V O

Hemleben, C., Spindler, M. & Anderson, O. (1989). Modern Planktonic Foraminifera. Springer-Verlag, New York. -. gs

Jenkins, D. G. (1965c). The origin of the species Globigerinoides trilobus (Reuss) in New Zealand. Contributions from the Cushman Foundation for Foraminiferal Research. 16(3): 116-120. gs V O

Jenkins, D. G. (1968). Acceleration of the evolutionary rate in the Orbulina lineage. Contributions from the Cushman Foundation for Foraminiferal Research. 19(4): 133-140. gs V O

Kennett, J. P. & Srinivasan, M. S. (1983). Neogene Planktonic Foraminifera. Hutchinson Ross Publishing Co., Stroudsburg, Pennsylvania. 1-265. gs

Loeblich, A. & Tappan, H. (1994). Foraminifera of the Sahul shelf and Timor Sea. Cushman Foundation for Foraminiferal Research, Special Publication. 31: 1-661. gs V O

Pearson, P. N., Shackleton, N. J. & Hall, M. A. (1997a). Stable isotopic evidence for the sympatric divergence of Globigerinoides trilobus and Orbulina universa (planktonic foraminifera). Journal of the Geological Society of London. 154: 295-302. gs

Poole, C. R. & Wade, B. S. (2019). Systematic taxonomy of the Trilobatus sacculifer plexus and descendant Globigerinoidesella fistulosa (planktonic foraminifera). Journal of Systematic Palaeontology. 1-42. gs

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

Reuss, A. E. (1850). Neue Foraminiferen aus den Schichten des Osterreichischen Tertiarbeckens. Denkschriften der kaiserlichen Akademie der Wissenschaften zu Wien Mathematisch-Naturwissenschaftlichen Classe. 1: 365-390. gs V O

Rögl, F. (2012). Globigerina triloba Reuss 1850 – Designation of a neotype. Annalen des Naturhistorischen Museums in Wien. 114: 179-191. gs V O

Spezzaferri, S. (1994). Planktonic foraminiferal biostratigraphy and taxonomy of the Oligocene and lower Miocene in the oceanic record. An overview. Palaeontographia Italica. 81: 1-187. gs

Spezzaferri, S., Olsson, R. K. & Hemleben, C. (2018c). Taxonomy, biostratigraphy, and phylogeny of Oligocene to Lower Miocene Globigerinoides and Trilobatus. In, Wade, B. S., Olsson, R. K., Pearson, P. N., Huber, B. T. & Berggren, W. A. (eds) Atlas of Oligocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication. 46(Chap 9): 269-306. gs V O

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. gs


Trilobatus trilobus compiled by the pforams@mikrotax project team viewed: 17-1-2021

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