pforams@mikrotax - Globorotaloides eovariabilis

Citation: Globorotaloides eovariabilis Huber & Pearson, in Olsson et al. 2006

Basionym: Globorotaloides eovariabilis

Synonyms:

Clavigerinella ?columbiana (Petters). McKeel and Lipps, 1975:258, pl.3: fig. 8a-c (partim; not pl. 4: fig. 6a, b =Parasubbotina eoclava Coxall, Huber, and Pearson) [lower middle Eocene, Elkton Siltstone, Coast Ranges, Oregon]. [Not Petters, 1954.]
?Globorotalia (Turborotalia) pseudoimitata Blow, 1979:1104-1105, pl. 101: figs. 1-3 [upper Paleocene Zone P5, DSDP Site 47, Shatsky Rise, northwest Pacific Ocean]; pl. 106: figs. 2-10; pl. 108: figs. 1-3 [lower Eocene Zone P6, Hole 20C, South Atlantic Ocean].
Globorotalia munda Jenkins.—Krasheninnikov and Basov, 1983:841 (partim), pl. 10: fig. 101 [lower Eocene, DSDP Site 511, Falkland Plateau, South Atlantic].[Not Jenkins, 1966.]
Globorotaloides aff. G. testarugosa Jenkins.—Stott and Kennett, 1990:560, pl. 7: fig. 11 [middle Eocene Zone AE4/5, ODP Hole 689B, Maud Rise, southern South Atlantic]. Huber, 1991:440, pl. 7: figs. 19, 20 [lower Oligocene, Zone AE9, ODP Hole 738B, Kerguelen Plateau, southern Indian Ocean]. [Not Jenkins, 1971.]
“Planorotalites” reissi (Loeblich and Tappan).—Huber, 1991:440, pl. 4: figs. 18-20 [lower Eocene Zone AE4/5, ODP Hole 738C, Kerguelen Plateau, southern Indian Ocean]. [Not Loeblich and Tappan, 1957.]
Globorotaloides aff. suteri Bolli.—Nocchi and others, 1991:268, pl. 4: figs. 4, 5 [lower middle Eocene Zone E8- E9, ODP Site 699, southern South Atlantic]. [Not Bolli, 1957b.]
Globorotaloides suteri Bolli.—Berggren, 1992:564, pl. 4: fig. 4 [upper Eocene G. suteri Zone ODP Hole 748B, Kerguelen Plateau, southern Indian Ocean]. [Not Bolli, 1957b.]
Globorotaloides sp. 1, Berggren, 1992: 568, pl. 4: fig. 11 [upper Eocene G. suteri Zone, ODP Hole 748B, Kerguelen Plateau, southern Indian Ocean].
Globorotaloides suteri Bolli.—Bolli, 1957:117, pl. 27, figs. 9a-c and 12a-b, G. suteri paratypes USNM P5655c and P5655d respectively [lower Oligocene, Globigerina ampliapertura Zone, Cipero Fm. Trinidad].—Jenkins and Orr, 1972:1106, pl. 36, figs. 10, 11 [lower Oligocene Pseudohastigerina barbadoensis Zone, DSDP Hole 77, eastern equatorial Pacific Ocean].—Poore and Brabb, 1977:260, pl. 1, figs. 11, 12 [lower Oligocene Zone P19-P20, San Lorenzo Fm., Rices Mudstone Member, Santa Cruz Mountains, California].—Krasheninnikov and Basov, 1983:840, pl. 8, figs. 1, 4 [upper Eocene, DSDP Hole 511, Falkland Plateau, South Atlantic Ocean].—Berggren, 1992:564, pl. 4, fig. 4 [upper Eocene Globorotaloides suteri Zone, ODP Hole 748B, Kerguelen Plateau, southern Indian Ocean]. [Not Bolli, 1957.]
Globorotaloides variabilis Bolli.—Kennett and Srinivasan, 1983:214, pl. 53, figs. 6-8 [upper Miocene Zone N16, DSDP Hole 289, Ontong Java Plateau, western equatorial Pacific Ocean]. [Not Bolli, 1957.]
Globorotalia munda Jenkins.—Krasheninnikov and Basov, 1983:841, pl. 10, fig. 11 [upper Eocene, DSDP Hole 511, Falkland Plateau, South Atlantic Ocean]. [Not Jenkins, 1965.]
Globorotaloides aff. G. testarugosa Jenkins.—Stott and Kennett, 1990:560, pl. 7, fig. 11 [middle Eocene Zone AE4/5, ODP Hole 689B, Maud Rise, sub-Antarctic South Atlantic Ocean].—Huber, 1991:440, pl. 7, figs. 19, 20 [lower Oligocene Zone AE9, ODP Hole 738B, Kerguelen Plateau, southern Indian Ocean]. [Not Jenkins, 1960.]
Globorotaloides sp. 1, Berggren, 1992:568, pl. 4, fig. 11 [upper Eocene Globorotaloides suteri Zone, ODP Hole 748B, Kerguelen Plateau, southern Indian Ocean].—Sexton and others, 2006:6, pl. 1, figs. 9, 10 [middle Eocene Zone E13, ODP Site 1052, Blake Nose, western North Atlantic Ocean].
Globorotaloides sp.—Li and others, 2003: pl. 1, fig. 17 [upper Eocene Zone P16, ODP Hole 1126D, Great Australian Bight].
Globorotaloides eovariabilis Huber and Pearson in Olsson and others, 2006a:79-83, pl. 5.4, figs. 1-3, 5-11 [middle Eocene Zone E10-E11, ODP Hole 647A, Labrador Sea], pl. 5.4, fig. 4 [middle Eocene Zone AE7, ODP Hole 690B, Maud Rise, southern Indian Ocean], pl. 5.4, figs. 12-17 [lower Eocene and lower Oligocene Zones AE2 and AO1, ODP Hole 738B, Kerguelen Plateau, southern Indian Ocean].—Pearson and Wade, 2009:206, pl. 5, fig. 7 [upper Oligocene Zone O6 (= O7), Cipero Fm., Trinidad]. [merged synonomy form Olsson 2006 & Coxall & Spezzaferri 2018]

Taxonomic discussion:

Globorotaloides eovariabilis is a small but distinctive species that occurs frequently in the < 150 μm size fraction (although the holotype is slightly larger). It is long-ranging and most abundant in high latitude Eocene to early Oligocene or equatorial assemblages. It is possible that it is a junior synonym of G. hexagonus and the possibility that the Paleogene species had a spinose wall, whereas modern G. hexagonus does not (see discussion above). Eocene Globorotaloides eovariabilis usually does not have a bulla, however, we have observed in Oligocene populations from different localities (e.g., ODP Site 647, North Atlantic Ocean, and Site 1137, southern Indian Ocean) times when bullate and non-bullate forms co-occur (Plate 4.5, Figs. 11, 12). Removal or natural breakage of the bulla reveals the typical G. eovariabilis morphology beneath (Plate 4.5, Figs. 13). [Coxall & Spezzaferri 2018]

Distinguishing features:
Parent taxon (Globorotaloides): Trochospiral test, ovate to spherical chambers; final chamber often small/bulla-like; cancellate wall.
This taxon: Test with 4½ to 6, final whorl chambers, increasing gradually in size.

Description

Test outline lobate, subcircular in axial view, axial periphery rounded to slightly compressed and pinched, biconvex, oval to egg-shaped in edge view; 3- 3½ whorls of slightly inflated chambers arranged in a flattened to slightly elevated trochospire; 14-15 chambers in adult tests, 4½-6½ in the final whorl increasing moderately in size; umbilicus shallow to moderately deep and narrow; umbilical sutures moderately depressed, curved, radial; spiral sutures initially indistinct, later weakly depressed, radial; aperture a low umbilical-extraumbilical arch extending one-third towards the peripheral margin, surrounded by a broad lip that extends into the umbilical area; tendency to develop an imperforate peripheral band in some Oligocene forms (modified from Olsson and others, 2006a). [Coxall & Spezzaferri 2018]

Normal perforate, coarsely cancellate, sacculifer-type wall texture, often with corroded interpore ridges resulting in a remnant wall texture consisting of distinct ‘rosettes’ around pores. Possibly spinose (modified from Olsson and others, 2006a). [Coxall & Spezzaferri 2018]

Holotype (USNM 523429) maximum diameter 0.18 mm, breadth 0.10 mm; paratype a (USNM 523430) maximum diameter 0.13 mm, breadth 0.80 mm; paratype b (USNM 523430) maximum diameter 0.15 mm, breadth 0.93 mm. [Coxall & Spezzaferri 2018]

Biogeography and Palaeobiology

Global, including low and mid-latitudes. Can be common in southern and northern high latitudes. There may be an affinity with high productivity conditions. [Coxall & Spezzaferri 2018]

Globorotaloides eovariabilis exhibits relatively positive δ18O and negative δ13C compared to other species suggesting that it occupied a sub-thermocline planktonic habitat similar to Catapsydrax (Coxall, unpublished). [Coxall & Spezzaferri 2018]

Globorotaloides eovariabilis evolved from Globorotaloides quadrocameratus (Olsson and others, 2006a). [Coxall & Spezzaferri 2018]

Biostratigraphic distribution

Geological Range:
Notes: Lower Eocene (Olsson and others, 2006a) to upper Oligocene Zone O7 (Pearson and Wade, 2009), possibly extending into the lower Miocene (recorded as Globorotaloides permicrus at DSDP Sites 360, 26, 563 and 516, Spezzaferri, 1994), although difficult to determine because of the close similarities with G. hexagonus. The holotype and paratype are from the middle Eocene of ODP Hole 647A, southern Labrador Sea, which was assigned to calcareous nannofossil Zone NP16 by Firth (1989) and dated as 40.2 Ma on the revised Site 647 biomagnetochronology of Firth and others (2013). [Coxall & Spezzaferri 2018]
Last occurrence (top): within M1 zone (21.12-22.96Ma, top in Aquitanian stage). Data source: Coxall & Spezzaferri 2018
First occurrence (base): within E7 zone (45.72-50.2Ma, base in Ypresian stage). Data source: Olsson et al. 2006

Primary source for this page: Coxall & Spezzaferri 2018 - Olig Atlas chap.4 p.97; Olsson et al. 2006 - Eocene Atlas, chap. 5, p. 79

References:

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. (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

Coxall, H. K. & Spezzaferri, S. (2018). Taxonomy, biostratigraphy, and phylogeny of Oligocene Catapsydrax, Globorotaloides, and Protentelloides. 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 4): 79-124. gs

Firth, J. V. (1989). Eocene and Oligocene calcareous nannofossils from the Labrador Sea, ODP Leg 105. Proceedings of the Ocean Drilling Program, Scientific Results. 105: 263-286. gs

Firth, J. V., Eldrett, J. S., Harding, I. C., Coxall, H. K. & Wade, B. S. (2013). Integrated biomagnetochronology for the Palaeogene of ODP Hole 647A: implications for correlating palaeoceanographic events from high to low latitudes, in Jovane, L., Herrero-Bervera, E., Hinnov, L.A., and Housen, B.A. (eds.), Magnetic Methods and the Timing of Geological Processes. Geological Society of London, Special Publications. 373: 29-78. 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

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

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

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

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. Initial Reports of the Deep Sea Drilling Project. 71: 789-820. gs

Li, Q., McGowran, B. & James, N. P. (2003b). Eocene–Oligocene planktonic forminiferal biostratigraphy of Sites 1126, 1130, 1132, and 1134, ODP Leg 182, Great Australian Bight. Proceedings of the Ocean Drilling Program, Scientific Results. 182: 1-28. gs

Loeblich, A. R. & Tappan, H. (1957b). Planktonic foraminifera of Paleocene and early Eocene Age from the Gulf and Atlantic coastal plains. 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: 173-198. gs

McKeel, D. R. & Lipps, J. J. (1975). Eocene and Oligocene planktonic foraminifera from the Central and Southern Oregon Coast Range. Journal of Foraminiferal Research. 5(4): 249-269. gs

Natland, M. L. (1938). New Species of Foraminifera from off the West Coast of North America and from the Later Tertiary of the Los Angeles Basin. Bulletin of the Scripps Institute of Oceanography, Tech. Ser. 4(5): 137-164. gs

Nocchi, M., Amici, E. & Premoli Silva, I. (1991). Planktonic foraminiferal biostratigraphy and paleoenvironmental interpretation of Paleogene faunas from the subantarctic transect, Leg 114. Proceedings of the Ocean Drilling Program, Scientific Results. 114: 233-273. gs

Olsson, R. K., Pearson, P. N. & Huber, B. T. (2006c). Taxonomy, biostratigraphy, and phylogeny of Eocene Catapsydrax, Globorotaloides, Guembelitrioides, Paragloborotalia, Parasubbotina, and Pseudoglobigerinella n. gen. 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 5): 67-110. gs O

Pearson, P. N. & Wade, B. S. (2009). Taxonomy and stable isotope paleoecology of well-preserved planktonic foraminifera from the uppermost Oligocene of Trinidad. Journal of Foraminiferal Research. 39: 191-217. gs

Petters, V. (1954). Tertiary and Upper Cretaceous foraminifera from Colombia, S. A. Contributions from the Cushman Foundation for Foraminiferal Research. 5(1): 37-41. gs

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. gs

Sexton, P. E., Wilson, P. A. & Pearson, P. N. (2006). Palaeoecology of late middle Eocene planktic foraminifera and evolutionary implications. Marine Micropaleontology. 60: 1-16. 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

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

test outline:	Lobate	chamber arrangement:	Trochospiral	edge view:	Equally biconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Globular	coiling axis:	Low	periphery:	N/A	aperture border:	Thick lip
umb chbr shape:	Globular	umbilicus:	Narrow	periph margin shape:	Broadly rounded	accessory apertures:	None
spiral sutures:	Weakly depressed	umb depth:	Shallow	wall texture:	Cancellate	shell porosity:	Macroperforate: >2.5µm
umbilical or test sutures:	Moderately depressed	final-whorl chambers:	4.5-6	N.B. These characters are used for advanced search. N/A - not applicable

Globorotaloides eovariabilis

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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