pforams@mikrotax - Globoturborotalita euapertura

Citation: Globoturborotalita euapertura (Jenkins, 1960)

Basionym: Globigerina euapertura Jenkins, 1960

Synonyms:

Globigerina euapertura Jenkins, 1960:351, pl. 1, figs. 8a-c [lower Miocene pre-Globoquadrina dehiscens dehiscens Zone, Lakes Entrance Oil Shaft, Victoria, southeastern Australia].—Jenkins and Orr, 1972:1088, pl. 9, figs. 1-6 [lower Oligocene C. cubensis Zone, DSDP Hole 77B, equatorial Pacific Ocean].—Stott and Kennett, 1990:559, pl. 7, fig. 7 [upper Oligocene Zone AP14a (= AO2, Huber and Quillévéré, 2005), DSDP Hole 690B, Maud Rise, South Atlantic Ocean].—Berggren, 1992a:563, pl. 4, fig. 16 [upper Oligocene Zone G. euapertura Zone (= AO2 of Huber and Quillévéré, 2005), ODP Hole 748B, Kerguelen Plateau, southern Indian Ocean].
Globigerina cf. euapertura Jenkins.—Jenkins and Orr, 1972:1088, pl. 9, figs. 7-9 [lower Miocene G. kugleri Zone, DSDP Hole 77B, equatorial Pacific Ocean].
“Globigerina” euapertura Jenkins.—Spezzaferri, 1994:30, pl. 39, fig. 1 [lower Miocene Subzone N4b, ODP Hole 709C, Indian Ocean], fig. 2 [upper Oligocene Zone P22, ODP Hole 538A, Gulf of Mexico].
Turborotalia euapertura (Jenkins).—Li and others, 2003:16, pl. P2, fig. 20 [lower Miocene, ODP Hole 1134A, Great Australian Bight].—Li and others, 2005:19, pl. 2 (partim), fig. 2 [Miocene, ODP Hole 1148A, South China Sea].
Globigerina woodi Jenkins.—Hooyberghs and De Meuter, 1972:27, pl. 8, fig. 4a [‘upper Oligocene’, Houthalan Sands, Belgium]. [Not Jenkins, 1960.]
Globigerina cf. G. woodi Jenkins.—Chaisson and Leckie, 1993:pl. 1, fig. 16 [lower Miocene, Subzone N4b, Hole 806B, western equatorial Pacific Ocean].
Not “Turborotalia” euapertura Jenkins.—Fleisher, 1975:pl. 3, figs. 8, 9 [lower Oligocene, “Turborotalia” ampliapertura Zone, DSDP Site 305, North Pacific Ocean] (= Dentoglobigerina prasaepis).
Not Globigerina euapertura Jenkins.—Poore, 1984:pl. 2, fig. 7 [lower Oligocene Zone OL2, DSDP Site 522, South Atlantic Ocean].—Leckie and others, 1993:123, pl. 4, fig. 10 [lower Oligocene Zone P18, ODP Hole 803D, Ontong Java Plateau, western equatorial Pacific Ocean], fig. 11 [upper Oligocene Subzone P21b, ODP Hole 803D, Ontong Java Plateau, western equatorial Pacific Ocean], figs. 12, 13 [lower Oligocene Subzone P21a, ODP Hole 628A, western North Atlantic Ocean] (= Dentoglobigerina prasaepis).
Not Globigerina euaperta Jenkins.—Loubere, 1985:pl. 4, fig. 12 (= microperforate).
Not Turborotalia euapertura Jenkins.—Li and others, 2005:pl. 2, fig. 1 [lower Oligocene, ODP Hole 1148A, South China Sea] (= Dentoglobigerina prasaepis).

Taxonomic discussion:

The taxonomic affinity of Globoturborotalita euapertura has long been debated. Many authors have considered this form to be homeomorphic with Dentoglobigerina prasaepis (Blow) or related to Turborotalia ampliapertura (Bolli), while others have referred it to the original genus designation Globigerina (Stott and Kennett, 1990; Huber, 1991; Huber and Quillévéré, 2005). Jenkins (1960) considered his new species to be intermediate between Globigerina venezuelana and Globigerina ampliapertura. Dentoglobigerina prasaepis was considered to be a junior synonym of G. euapertura by Jenkins and Orr (1972) and Fleisher (1975). However, inspection of SEM images of the holotype and our new material, indicates the taxon has a cancellate test that differs from the wall structure of Dentoglobigerina or Turborotalia. We therefore conclude that euapertura belongs to Globoturborotalita, and is unrelated to Turborotalia ampliapertura and species of Dentoglobigerina as previously suggested. This refined diagnosis is consistent with Huber and Quillévéré’s (2005) concept of this species as used to define the upper Oligocene “Globigerina euapertura Highest-occurrence Zone” (Zone AO4). Jenkins (1960) reports an increase in the size of G. euapertura specimens in the younger part of the range but this has not been verified by morphometric studies elsewhere. [Spezzaferri et al. 2018]

Distinguishing features:
Parent taxon (Globoturborotalita): Trochospiral test with a single, large, open umbilical aperture. Cancellate wall. 4-4½ chambers in final whorl
This taxon: 4 wedge-like chambers in the final whorl, last chamber reniform; aperture broad & low, confined to the umbilicus; sutures deeply incised.

Description

Low trochospiral, medium sized test, consisting of 3 whorls, weakly lobulate in outline, 4 subglobular, slightly embracing chambers in the last whorl, increasing slowly in size, sutures incised, straight to slightly curved on both sides; low arched umbilical aperture, bordered by a thin, indistinct rim; final chamber reniform in shape, directly over the umbilicus; in edge view chambers ovoid in shape, ultimate chamber extends over the umbilicus, oval to subcircular in outline. [Spezzaferri et al. 2018]

Normal perforate, spinose, sacculifer-type wall texture, an average of about 20 pores/50 μm2 test surface area.

Holotype maximum diameter 0.30 mm. [Spezzaferri et al. 2018]

Biogeography and Palaeobiology

More common in colder water high southern latitude environments, though it has been recorded in subtropical sites (Premoli Silva and Boersma, 1988). [Spezzaferri et al. 2018]

Poore and Matthews (1984) suggest an intermediate (thermocline) dwelling habitat for G. euapertura, however they find inconsistent results and acknowledge that more than one morphospecies may have been analyzed. The specimens analyzed by Wade and Pearson (2008) are now considered to be Dentoglobigerina prasaepis. [Spezzaferri et al. 2018]

It probably evolved from G. woodi by developing a more rounded periphery, a lower, wider arched aperture and more wedge like chambers. [Spezzaferri et al. 2018]

Most likely ancestor: Globoturborotalita woodi - at confidence level 3 (out of 5). Data source: Spezzaferri et al. 2018.

Biostratigraphic distribution

Geological Range:
Notes: Not currently well constrained. This species has been recorded from the upper Eocene through lower Miocene (e.g., Leckie and others, 1993), though it has frequently been confused with D. venezuelana and D. prasaepis. It is considered valuable in mid- to high southern latitudes. Jenkins (1966) erected the G. euapertura Zone from the ‘mid’ Oligocene to lower Miocene, a concept that has been carried over in recent high southern latitude biozonation schemes (Stott and Kennett, 1990; Berggren, 1992a,b; Huber and Quillévéré, 2005). Spezzaferri and Premoli Silva (1991) record a lowest occurrence in mid- Subzone P21a, Huber and Quillévéré (2005) record this species from lower to middle Zone AO1.

Berggren (1992b) constrain the LAD at the Kerguelen Plateau to Chron C6Cn.2n (23.8 Ma), close to the Oligocene/Miocene boundary. However, Globoturborotalita euapertura has frequently been recorded from lower Miocene sediments and was indeed described from the lower Miocene.

Primary source for this page: Spezzaferri et al. 2018 - Olig Atlas chap.8 p.244

References:

Berggren, W. A. (1992). Paleogene planktonic foraminifer magnetobiostratigraphy of the southern Kerguelen Plateau (sites 747-749). Proceedings of the Ocean Drilling Program, Scientific Results. 120: 551-568. 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

Fleisher, R. (1975). Oligocene planktonic foraminiferal biostratigraphy, central North Pacific Ocean, DSDP Leg 32. Initial Reports of the Deep Sea Drilling Project. 32: 753-763. gs

Hooyberghs, H. J. F. & de Meuter, F. (1972). Biostratigraphy and inter-regional correlation of the Miocene deposits of Northern Belgium based on planktonic foraminifera; the Oligocene-Miocene boundary on the southern edge of the North Sea basin, Brussels. Koninklijke Vlaamse Academie voor Wetenschappen, Letteren en Schone Kunsten van België. -. gs

Huber, B. T. & Quillévéré, F. (2005). Revised Paleogene planktic foraminiferal biozonation for the Austral Realm. Journal of Foraminiferal Research. 35: 299-314. gs

Huber, B. T. (1991c). Paleogene and Early Neogene Planktonic Foraminifer Biostratigraphy of Sites 738 and 744, Kerguelen Plateau (Southern Indian Ocean). Proceedings of the Ocean Drilling Program, Scientific Results. 119: 427-449. gs

Huber, B. T., Olsson, R. K. & Pearson, P. N. (2006). Taxonomy, biostratigraphy, and phylogeny of Eocene microperforate planktonic foraminifera (Jenkinsina, Cassigerinelloita, Chiloguembelina, Streptochilus, Zeauvigerina, Tenuitella, and Cassigerinella) and Problematica (Dipsidripella). In, Pearson, P. N., Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (eds) Atlas of Eocene Planktonic Foraminifera. Cushman Foundation for Foraminiferal Research, Special Publication . 41(Chap 16): 461-508. gs O

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

Jenkins, D. G. (1966b). Planktonic foraminiferal zones and new taxa from the Danian to lower Miocene of New Zealand. New Zealand Journal of Geology and Geophysics. 8 [1965](6): 1088-1126. 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., McGowran, B. & Brunner, C. A. (2003a). Neogene planktonic foraminiferal biostratigraphy of Sites 1126, 1128, 1130, 1132, and 1134, ODP Leg 182, Great Australian Bight. Proceedings of the Ocean Drilling Program, Scientific Results. 182: 1-67. gs

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

Loubere, P. (1985). Population diversity of planktonic foraminifers and stable isotope record across the Eocene/Oligocene boundary: Hole 549A. Initial Reports of the Deep Sea Drilling Project. 80: 557-566. gs

Poore, R. Z. & Matthews, R. K. (1984). Oxygen isotope ranking of late Eocene and Oligocene planktonic foraminifers: implications for Oligocene sea-surface temperatures and global ice-volume. Marine Micropaleontology. 9: 111-134. 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

Premoli Silva, I. & Boersma, A. (1988). Atlantic Eocene planktonic foraminiferal historical biogeography and paleohydrographic indices. Palaeogeography Palaeoclimatology Palaeoecology. 67: 315-356. gs

Spezzaferri, S. & Premoli Silva, I. (1991). Oligocene planktonic foraminiferal biostratigraphy and paleoclimatic interpretation from Hole 538A, DSDP Leg 77, Gulf of Mexico. Palaeogeography Palaeoclimatology Palaeoecology. 83: 217-263. 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

Spezzaferri, S., Olsson, R. K., Hemleben, C., Wade, B. S. & Coxall, H. K. (2018d). Taxonomy, biostratigraphy, and phylogeny of Oligocene and Lower Miocene Globoturborotalita. 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 8): 231-268. gs

Stott, L. D. & Kennett, J. P. (1990). The Paleoceanographic and Paleoclimatic signature of the Cretaceous/Paleogene boundary in the Antarctic: Stable isotopic results from ODP Leg 113. Proceedings of the Ocean Drilling Program, Scientific Results. 113: 829-848. gs

Wade, B. S. & Pearson, P. N. (2008). Planktonic foraminiferal turnover, diversity fluctuations and geochemical signals across the Eocene/Oligocene boundary in Tanzania. Marine Micropaleontology. 68: 244-255. gs

test outline:	Lobate	chamber arrangement:	Trochospiral	edge view:	Concavo-convex	aperture:	Umbilical
sp chamber shape:	Globular	coiling axis:	Low	periphery:	N/A	aperture border:	Thin lip
umb chbr shape:	Subtriangular	umbilicus:	Wide	periph margin shape:	Broadly rounded	accessory apertures:	None
spiral sutures:	Weakly depressed	umb depth:	Deep	wall texture:	Cancellate	shell porosity:	Macroperforate: >2.5µm
umbilical or test sutures:	Moderately depressed	final-whorl chambers:	4-4	N.B. These characters are used for advanced search. N/A - not applicable

Globoturborotalita euapertura

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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