pforams@mikrotax - Globoquadrina dehiscens pforams@mikrotax - Globoquadrina dehiscens

Globoquadrina dehiscens

Classification: pf_cenozoic -> Globigerinidae -> Globoquadrina -> Globoquadrina dehiscens
Sister taxa: G. conglomerata, G. dehiscens, G. sp.


Citation: Globoquadrina dehiscens (Chapman, Parr & Collins, 1934)
taxonomic rank: Species
Basionym: Globorotalia dehiscens Chapman, Parr & Collins, 1934

(Note: This is a common, distinctive and biostratigraphically important species in the Miocene. Here we present an abbreviated synonymy list)

Taxonomic discussion:

We were not able to obtain new images of the holotype so we use the type illustration as our guide (Pl. 11.17, Figs. 1-3). This is a common, distinctive and biostratigraphically important form. When the diagnostic characteristics are well developed it is virtually unmistakable but populations can be variable and some individuals can show morphological overlap with species such as D. tripartita, D. larmeui, D. binaiensis, and D. baroemoenensis. The latter species, in particular, can show sharply angular chambers with pustulose umbilical shoulders, including the holotype itself (see discussion under D. baroemoenensis). Many authors since Grimsdale (1951) and Blow (1959) have considered Globorotalia quadraria Cushman and Ellisor to be a junior synonym of Globoquadrina dehiscens, which we have confirmed with new SEM images of the holotype of Globorotalia quadraria. According to Jenkins (1960), who examined topotype specimens, Globorotalia subdehiscens Finlay is a probable synonym of dehiscens. We have not investigated all possible synonymies in the Miocene, which we defer to future work. Globoquadrina dehiscens has long been considered nonspinose since Steineck and Fleisher (1978), although Cifelli (1982) argued that it was spinose. We have not observed spines or spine holes in this species but include it in the spinose group because of its apparently close evolutionary relationship with spinose Dentoglobigerina. [Wade et al. 2018]

Catalog entries: Globorotalia dehiscens, Globoquadrina subdehiscens, Globorotalia quadraria

Type images:

Distinguishing features:
Parent taxon (Globoquadrina): Trochospiral with quadrate to subquadrate profile; aperture in interiomarginal / umbilical-extraumbilical, one or more tooth-like projections extending into the umbilicus.
This taxon: Low trochospiral, spiral side almost flat, umbilical side strongly convex; subquadrate;  3½-4 chambers in final whorl; umbilicus large, deep; aperture low, umbilical, covered by umbilical tooth

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.


Low trochospiral, peripheral margin quadrate; in spiral view 4 chambers rapidly increasing in size (although the final chamber can be kummerform), elongate oval in shape, sutures flush, slightly curved; in umbilical view 4 chambers rapidly increasing in size, triangular in outline, becoming progressively flattened and angular; umbilicus open, surrounded by steep walls of chambers, diagonally flattened umbilical face of final chamber, umbilical shoulder sometimes pustulose, umbilical face wholly or partially non-perforate with an elongate pointed triangular apertural tooth; in edge view chambers triangular and projecting over the umbilicus, spiral side flat. [Wade et al. 2018]

Wall type:
Normal perforate, weakly cancellate. [Wade et al. 2018]

Maximum diameter 0.30 mm, minimum diameter 0.25 mm. [Wade et al. 2018]

Character matrix
test outline:Subquadratechamber arrangement:Trochospiraledge view:Planoconvexaperture:Umbilical
sp chamber shape:Subrectangularcoiling axis:Low-moderateperiphery:N/Aaperture border:Teeth
umb chbr shape:Globularumbilicus:Wideperiph margin shape:Moderately roundedaccessory apertures:None
spiral sutures:Weakly depressedumb depth:Deepwall texture:Cancellateshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:3.5-4 N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution

Widespread, cosmopolitan. [Wade et al. 2018]

Isotope paleobiology
Classified as an intermediate-dweller by Keller (1985). Recorded as erratic and variable by Pearson and Shackleton (1995). [Wade et al. 2018]

Phylogenetic relations
Globigerina dehiscens praedehiscens Blow and Banner has long been cited as the ancestor of G. dehiscens. However, G. praedehiscens is now considered a junior synonym of D. tripartita. We concluded that this taxon evolved from Dentoglobigerina larmeui as originally suggested by Jenkins (1960). [Wade et al. 2018]

Most likely ancestor: Dentoglobigerina larmeui - at confidence level 3 (out of 5). Data source: Wade et al. 2018.

Biostratigraphic distribution

Geological Range:
Notes: The lowest occurrence of G. dehiscens is used to mark the base of Subzone M1b (Kennett and Srinivasan, 1983; Berggren and others, 1995; Wade and others, 2011). This appears to be reliable in the subtropics (e.g. Keller, 1980; Kennett and Srinivasan, 1983; Poore, 1984, Chaisson and Leckie, 1993; Leckie and others, 1993; Pearson, 1995) but a lower occurrence has been recorded in the southern latitudes of the Atlantic and Pacific Oceans (Premoli Silva and Spezzaferri, 1990; Spezzaferri, 1994). The highest occurrence in the uppermost Miocene has not been investigated in this study. [Wade et al. 2018] Since the first appearance of Gq. dehiscens is close to the Oligocene-Miocene boundary, it is useful in approximating this boundary in oceanic sequences (Srinivasan and Kennett, 1981a, 1981b, 1983). Although Gq. dehiscens has been found in some Pliocene sediments (Bizon and Bizon, 1972; Jenkins and Orr, 1972; Kennett and Srinivasan, 1975), its last appearance is widely accepted as marking the Miocene-Pliocene boundary in most areas (Berggren, 1973). [Kennett & Srinivasan 1983]
Last occurrence (top): in mid part of M14 [Atl.] zone (54% up, 5.9Ma, in Messinian stage). Data source: Wade et al. (2011), additional event; position within zone determined by linear interpolation from data in table 1 of Wade et al. (2011).
First occurrence (base): at base of M1b subzone (0% up, 22.4Ma, in Aquitanian stage). Data source: Wade et al. (2011), zonal marker

Plot of occurrence data:

Primary source for this page: Wade et al. 2018 - Olig Atlas chap.11 p.377; Kennett & Srinivasan 1983, p.184


Aze, T. et al. (2011). A phylogeny of Cenozoic macroperforate planktonic foraminifera from fossil data. Biological Reviews. 86: 900-927. gs

Berggren, W. A., Kent, D. V., Swisher, I. , C. C. & Aubry, M. -P. (1995b). A revised Cenozoic geochronology and chronostratigraphy. In, Berggren, W. A., Kent, D. V., Aubry, M. -P. & Hardenbol, J. (eds) Geochronology, Time Scales and Global Stratigraphic Correlations. SEPM (Society for Sedimentary Geology) Special Publication No. 54, 129-212. gs

Bizon, G. & Bizon, J. -J. (1972). Atlas des Pricipaux Foraminiferes Planctoniques du Bassin Mediterraneen Oligocene a Quaternaire. Technip, France. -. gs

Blow, W. H. (1959). Age, correlation, and biostratigraphy of the upper Tocuyo (San Lorenzo) and Pozon Formations, eastern Falcon, Venezuela. Bulletins of American Paleontology. 39(178): 67-251. 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. & Saunders, J. B. (1985). Oligocene to Holocene low latitude planktic foraminifera. In, Bolli, H. M., Saunders, J. B. & Perch-Neilsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge, UK 155-262. gs

Bolli, H. M. (1957b). Planktonic foraminifera from the Oligocene-Miocene Cipero and Lengua formations of Trinidad, B.W.I. 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: 97-123. gs

Chaisson, W. P. & Leckie, R. M. (1993). High-resolution Neogene planktonic foraminifer biostratigraphy of Site 806, Ontong Java Plateau (Western Equatorial Pacific). Proceedings of the Ocean Drilling Program, Scientific Results. 130: 137-178. gs

Chapman, F., Parr, W. J. & Collins, A. C. (1934). Tertiary foraminifera of Victoria, Australia - The Balcombian deposits of Port Phillip. part III. Zoological Journal of the Linnean Society. 38(262): 553-577. gs

Chaproniere, G. C. H. (1981). Late Oligocene to Early Miocene planktic Foraminiferida from Ashmore Reef no. 1 well, northwest Australia. Alcheringa. 5: 103-131. gs

Cifelli, R. (1982). Early Occurrences and some Phylogenetic Implications of Spiny, Honeycomb Textured Planktonic Foraminifera. Journal of Foraminiferal Research. 12(2): 105-115. gs

Cushman, J. A. & Ellisor, A. C. (1939). New species of foraminifera from the Oligocene and Miocene. Contributions from the Cushman Laboratory for Foraminiferal Research. 15: 1-14. gs

Finlay, H. J. (1947). New Zealand foraminifera: Key species in stratigraphy - no. 5. New Zealand Journal of Science and Technology. 28(5): 259-292. gs

Fox, L. R. & Wade, B. S. (2013). Systematic taxonomy of early–middle Miocene planktonic foraminifera from the equatorial Pacific Ocean: Integrated Ocean Drilling Program, Site U1338. Journal of Foraminiferal Research. 43: 374-405. gs

Grimsdale, T. F. (1951). Correlation, age determination, and the Tertiary pelagic Foraminifera. In, Proceedings of the Third World Petroleum Congress. 1: 463-475. gs

Jenkins, D. G. & Orr, W. N. (1972). Planktonic foraminiferal biostratigraphy of the east equatorial Pacific--DSDP Leg 9. Initial Reports of the Deep Sea Drilling Project. 9: 1059-1193. gs O

Jenkins, D. G. (1960). Planktonic foraminifera from the Lakes Entrance oil shaft, Victoria, Australia. Micropaleontology. 6: 345-371. gs

Keller, G. (1980). Planktonic foraminiferal biostratigraphy and paleoceanography of the Japan Trench, Deep Sea Drilling Project, Leg. 57. Initial Reports of the Deep Sea Drilling Project. 57: 809-834. gs

Keller, G. (1985). Depth stratification of planktonic foraminifers in the Miocene Ocean. In, Kennett, J. P. (ed.) The Miocene Ocean: Paleoceanography and Biogeography. GSA Memoir . 163: 1-337. gs

Kennett, J. P. & Srinivasan, M. S. (1975). Stratigraphic occurrences of the Miocene planktonic foraminifer Globoquadrina dehiscens in Early Pliocene sediments of the Indian Ocean. Revista Española de Micropaleontología. 7(1): 5-14. gs

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

Lam, A. & Leckie, R. M. (2020a). Late Neogene and Quaternary diversity and taxonomy of subtropical to temperate planktic foraminifera across the Kuroshio Current Extension, northwest Pacific Ocean. Micropaleontology. 66(3): 177-268. gs

Leckie, R. M., Farnham, C. & Schmidt, M. G. (1993). Oligocene planktonic foraminifer biostratigraphy of Hole 803D (Ontong Java Plateau) and Hole 628A (Little Bahama Bank), and comparison with the southern high latitudes. Proceedings of the Ocean Drilling Program, Scientific Results. 130: 113-136. gs

Li, Q., Jian, Z. & Su, X. (2005). Late Oligocene rapid transformations in the South China Sea. Marine Micropaleontology. 54: 5-25. gs

Norris, R. D. (1998). Planktonic foraminifer biostratigraphy: Eastern Equatorial Atlantic. Proceedings of the Ocean Drilling Program, Scientific Results. 159: 445-479. gs O

Pearson, P. N. & Shackleton, N. J. (1995). Neogene multispecies planktonic foraminifer stable isotope record, Site 871, Limalok Guyot. Proceedings of the Ocean Drilling Program, Scientific Results. 144: 401-410. gs

Pearson, P. N. (1995). Planktonic foraminifer biostratigraphy and the development of pelagic caps on guyots in the Marshall Islands group. Proceedings of the Ocean Drilling Program, Scientific Results. 144: 21-59. gs

Poore, R. Z. (1984). Middle Eocene through Quaternary planktonic foraminifers from the southern Angola Basin: Deep Sea Drilling Project Leg 73,. Initial Reports of the Deep Sea Drilling Project. 73: 429-448. gs

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

Premoli Silva, I. & Spezzaferri, S. (1990). Paleogene planktonic foraminifer biostratigraphy and paleoenvironmental remarks on paleogene sediments from Indian Ocean sites, Leg 115. Proceedings of the Ocean Drilling Program, Scientific Results. 115: 277-314. gs

Saito, T., Thompson, P. R. & Breger, D. (1976). Skeletal ultra-microstructure of some elongate-chambered planktonic foraminifera and related species. In, Takayanagi, Y. & Saito, T. (eds) Progress in Micropaleontology, Special Publication. Micropaleontology Press, The American Museum of Natural History, New York 278-304. gs

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

Srinivasan, M. S. & Kennett, J. P. (1981a). A review of Neogene planktonic foraminiferal biostratigraphy: applications in the equatorial and south Pacific. SEPM Special Publication. 395-432. gs

Srinivasan, M. S. & Kennett, J. P. (1981b). Neogene planktonic foraminiferal biostratigraphy and evolution: equatorial to subantarctic, south Pacific. Marine Micropaleontology. 6: 499-533. gs

Srinivasan, M. S. & Kennett, J. P. (1983). The Oligocene-Miocene boundary in the South Pacific. Geological Society of America, Bulletin. 94: 798-812. gs

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

Steineck, P. L. & Fleisher, R. L. (1978). Towards the classical evolutionary reclassification of Cenozoic Globigerinacea (Foraminiferida). Journal of Paleontology. 52: 618-635. gs

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

Wade, B. S., Pearson, P. N., Olsson, R. K., Fraass, A. J., Leckie, R. M. & Hemleben, C. (2018c). Taxonomy, biostratigraphy, and phylogeny of Oligocene and Lower Miocene Dentoglobigerina and Globoquadrina. 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 11): 331-384. gs


Globoquadrina dehiscens compiled by the pforams@mikrotax project team viewed: 3-3-2024

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