pforams@mikrotax - Paragloborotalia siakensis

Citation: Paragloborotalia siakensis (LeRoy, 1939)

Basionym: Globigerina siakensisLeRoy, 1939

Synonyms:

Globorotalia siakensis LeRoy, 1939:262, pl. 4, figs. 20-22 [Miocene?, Rokan-Tapanoeli region, central Sumatra].—Berggren and Amdurer, 1973, pl. 28, figs. 6, 7 [lower Miocene Zone N4, DSDP Site 14, South Atlantic Ocean], fig. 8 [upper Oligocene Subzone P21b, DSDP Site 17B, South Atlantic Ocean].—Kennett, 1973, pl. 14, figs. 1, 2 [middle Miocene G. mayeri Zone, DSDP Site 206, New Caledonia Basin, western South Pacific Ocean].—Stainforth and others, 1975:317, 320, fig. 143.1, 2 [lower Miocene Catapsydrax dissimilis Zone, Cipero Fm., Trinidad]; fig. 143.3 (holotype drawing reproduced); fig. 143.4, 5 [middle Miocene Globorotalia fohsi fohsi Zone, corehole, Gulf of Mexico].—Iaccarino and Salvatorini, 1979, pl. 3, figs. 10, 14 [middle Miocene Zone N12, DSDP Site 398, Vigo Seamount, eastern North Atlantic Ocean].—Berggren and others, 1983, pl. 3, figs. 8-10 [lower Miocene Zone N5, DSDP Site 516, Rio Grande Rise, western South Atlantic Ocean].
Globorotalia (Turborotalia) siakensis LeRoy.—Quilty, 1976:647, pl. 14, figs. 5, 6 [mid Miocene Zone N10/N11, DSDP Site 319, southeastern Pacific Ocean].—Molina, 1979:239-241, pl. 28, figs. 1A-C [lower Miocene G. primordius Zone, Levigado NA-4, Spain].
Globorotalia (Jenkinsella) siakensis LeRoy.—Kennett and Srinivasan, 1983:172, pl. 42, figs. 1, 6-8 [middle Miocene Zone N9, DSDP Site 289, Ontong Java Plateau, western equatorial Pacific Ocean].
Paragloborotalia siakensis (LeRoy).—Spezzaferri and Premoli Silva, 1991:253, pl. XI, figs. 2a-c [upper Oligocene Zone P22, DSDP Hole 538A, Catoche Knoll, Gulf of Mexico].—Spezzaferri, 1994:55, pl. 21, figs. 1a-c [reproduced from Premoli Silva and Spezzaferri, 1991, pl. 11, figs. 2a-c], figs. 2a-c [upper Oligocene Zone P22, DSDP Hole 667A, Sierra Leone Rise, equatorial Atlantic Ocean].—Fox and Wade, 2013:401, fig. 15.1-5, fig. 21 [middle Miocene Zone M6, IODP Hole U1338C, eastern equatorial Pacific Ocean].—Sanchez and others, 2014:116-117, pl. 11, figs. 1-8 [lower Miocene Catapsydrax dissimilis Zone, Cipero Fm., Trinidad], pl. 11, figs. 9-16 [lower Miocene Globorotalia fohsi peripheroronda Zone, Carapita Fm., eastern Venezuela Basin].
Globorotalia cf. mayeri Cushman and Ellisor.—Keller, 1981:125-127, pl. 2, 7 figures [upper Oligocene Zone P22, DSDP Site 292, Benham Rise, western North Pacific Ocean].
Globorotalia mayeri Cushman and Ellisor.—Bolli and Saunders, 1982a, pl. 1, figs. 25, 26, 30, 36, 38; pl. 2, figs. 1-6, 8, 9, 14-17, 21-31, 36, 38, 43-45; pl. 3, 1-6, 13-18, 22-29, 32-43 [upper Oligocene to middle Miocene, Globigerina ciperoensis ciperoensis Zone to Globorotalia mayeri Zone, Cipero Fm., Trinidad].
Paragloborotalia semivera (Hornibrook)/Paragloborotalia mayeri (Cushman and Ellisor) group.—Leckie and others, 1993:125, pl. 7, figs. 5-8, 10-14 [upper Oligocene Zone P22, ODP Hole 803D, Ontong Java Plateau, western equatorial Pacific Ocean; upper Oligocene Zone P22, ODP Hole 628A, Little Bahama Bank, western North Atlantic Ocean].
Not Globorotalia siakensis LeRoy.—Jenkins, 1960:366, 368, pl. 5, figs. 7a-c [lower Miocene Globigerinoides trilobus trilobus Zone, Lakes Entrance Oil Shaft, Victoria, Australia] (= Globorotalia bella).—Postuma, 1971:358, pl. on p. 359 [Trinidad] (= P. mayeri).

Taxonomic discussion:

Bolli and Saunders (1982a) argued that siakensis is synonymous with P. mayeri, but many workers differentiate the two forms based on the radial spiral sutures and lower arched aperture in siakensis, and the slightly curved spiral sutures and higher-arched aperture in mayeri (e.g., Kennett and Srinivasan, 1983; Spezzaferri and Premoli Silva, 1991; Spezzaferri, 1994; Pearson and Wade, 2009). Other than these subtle differences, the two taxa are very similar and share a highest occurrence in the early late Miocene (top of Zone M11/N14; Wade and others, 2011). Paragloborotalia siakensis is the ‘primitive’ form, initially very small with 5 chambers in the final whorl and radial spiral sutures in the early to mid-Oligocene, increasing in size and giving rise to P. mayeri s.s. with 5 chambers in the final whorl and slightly curved spiral sutures in the latest Oligocene; both taxa then increase to 6-7 chambers in the early to middle Miocene. According to Spezzaferri and Premoli Silva (1991), small specimens of P. siakensis (150 μm) appear in Subzone P21a of the Gulf of Mexico, while even larger specimens (>250 μm) appear within Zone P22 in the Indian Ocean. [Leckie et al. 2018]

In the near topotype material discussed and illustrated by Zachariasse and Sudijono (2012), specimens of P. siakensis generally have 5 chambers in the final whorl with a range of 4½-6½ chambers. They note that kummerform chambers are common, including one of the two specimens illustrated by LeRoy (1944). The aperture is variable from low to moderately high arch, with well-developed lip; some specimens lack a well-developed lip and instead have an imperforate rim around the aperture (e.g., Pearson and Wade, 2009). [Leckie et al. 2018]

Distinguishing features:
Parent taxon (Paragloborotalia): Very low trochospiral test with low-arched umbilical-extraumbilical aperture with a thick lip; 4-5 chambers in the ultimate whorl, and a coarsely cancellate, sacculifer-type wall.
This taxon: Like P. nana but with more chambers (5-7) in the final whorl, less embracing chambers, more rapid rate of chamber expansion, and a higher arched aperture.

Description

Test large in size; low trochospiral, strongly lobulate in equatorial outline, chambers globular, inflated, slightly embracing; some specimens may develop a kummerform final chamber; 4½-5½ chambers in the ultimate whorl of mid- to late Oligocene forms, up to 6-7 chambers in latest Oligocene to middle Miocene forms, increasing rapidly in size in initial whorl and slowly in the final whorl; in spiral view chambers subspherical, arranged in 2½-3 whorls, sutures depressed, radial; in umbilical view chambers spherical to subspherical, sutures depressed, radial, umbilicus narrow moderately deep; aperture umbilical-extraumbilical, low to moderately high arch, bordered by a prominent lip; in edge view chambers spherical, spiral side flat to slightly convex, umbilical side slightly convex, periphery broadly rounded. [Leckie et al. 2018]

Normal perforate, coarsely cancellate, sparsely spinose in life (Hilgen and others, 2000; Zachariasse and Sudijono, 2012; Sanchez and others, 2014), heavy gametogenetic calcification is often present.

Maximum diameter of holotype 0.40 mm, maximum thickness 0.28 mm (original measurements); maximum diameter 0.41 mm, thickness 0.25 mm (remeasured this study). [Leckie et al. 2018]

Biogeography and Palaeobiology

According to Kennett and Srinivasan (1983), siakensis is more common in equatorial and warm subtropical locations, while mayeri is more common in temperate locations. Spezzaferri (1994) reports a cosmopolitan distribution for siakensis. [Leckie et al. 2018]

Late Oligocene P. siakensis from Trinidad suggest an upper thermocline depth of calcification with no photosymbionts (Pearson and Wade, 2009). Matsui and others (2016) interpreted a lower mixed-layer habitat for the late Oligocene siakensis group (including mayeri and semivera) from the equatorial Pacific Ocean. Gasperi and Kennett (1993) reported consistently low δ18O values through the lower and middle Miocene of DSDP Site 289 in the western equatorial Pacific suggesting a mixed-layer habitat. [Leckie et al. 2018]

Paragloborotalia siakensis was probably derived from nana by the addition of another chamber in the final whorl, less embracing chambers, more rapid rate of chamber expansion, and a higher arched aperture. Alternatively, siakensis may have been derived from opima based on many of the same morphological changes, but the earliest forms of siakensis were small suggesting that nana was the more likely ancestor. Paragloborotalia mayeri is most likely descended from siakensis in the latest Oligocene (Kennett and Srinivasan, 1983; Premoli Silva and Spezzaferri, 1991; Spezzaferri, 1994). [Leckie et al. 2018]

Biostratigraphic distribution

Geological Range:
Notes: Lower Oligocene Zone O3 to upper Miocene Zone M11 (Spezzaferri and Premoli Silva, 1991; Spezzaferri, 1994; Wade and others, 2011). [Leckie et al. 2018]
Last occurrence (top): within M11 zone (10.46-11.63Ma, top in Tortonian stage). Data source: Leckie et al. 2018
First occurrence (base): within O3 zone (29.18-30.28Ma, base in Rupelian stage). Data source: Leckie et al. 2018

References:

Berggren, W. A. & Amdurer, A. (1973). Late Paleogene (Oligocene) and Neogene planktonic foraminiferal biostratigraphy of the Atlantic Ocean (Lat. 30N to Lat. 30S). Rivista Italiana di Paleontologia e Stratigrafia. 79: 337-392. gs

Berggren, W. A., Aubry, M. -P. & Hamilton, N. (1983). Neogene magnetobiostratigraphy of DSDP Site 516, Rio Grande Rise (South Atlantic). Initial Reports of the Deep Sea Drilling Project. 72: 675-713. gs

Bolli, H. M. & Saunders, J. B. (1982a). Globorotalia mayeri and its relationship to Globorotalia siakensis and Globorotalia continuosa,. Journal of Foraminiferal Research. 12(1): 39-50. gs

Bolli, H. M. & Saunders, J. B. (1982b). Annotation Globorotalia mayeri and Globorotalia siakensis: Priorities. Journal of Foraminiferal Research. 12(4): 369-. 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

Gasperi, J. T. & Kennett, J. P. (1993). Vertical thermal structure evolution of Miocene surface waters; western Equatorial Pacific DSDP Site 289. Marine Micropaleontology. 22: 235-254. gs

Hilgen, F. J., Krijgsman, W., Raffi, I., Turco, E. & Zachariasse, W. J. (2000). Integrated stratigraphy and astronomical calibration of the Serravallian/Tortonian boundary section at Monte Gibliscemi (Sicily, Italy). Marine Micropaleontology. 38: 181-211. gs

Iaccarino, S. & Salvatorini, G. (1979). Planktonic foraminiferal biostratigraphy of Neogene and Quaternary of Site 398 of DSDP Leg 47B. Initial Reports of the Deep Sea Drilling Project. 47(2): 255-285. gs

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

Keller, G. (1981a). Origin and evolution of the genus Globigerinoides in the Early Miocene of the northwestern Pacific, DSDP Site 292. Micropaleontology. 27(3): 293-304. gs

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

Kennett, J. P. (1973). Middle and Late Cenozoic planktonic foraminiferal biostratigraphy of the southwest Pacific-DSDP Leg 21. Initial Reports of the Deep Sea Drilling Project. 21: 575-639. gs

King, D. J., Wade, B. S. & Giles Miller, C. G. (2023). Biostratigraphic utility of coiling direction in Miocene planktonic foraminiferal genus Paragloborotalia. Newsletters on Stratigraphy. 56(3): 331-355. 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

Leckie, R. M. et al. (2018). Taxonomy, biostratigraphy, and phylogeny of Oligocene and Lower Miocene Paragloborotalia and Parasubbotina. 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 5): 125-178. gs

LeRoy, L. W. (1939). Some small foraminifera ostracoda and otoliths from the Neogene (Miocene) of the Rokan-Tapanoeli area, central Sumatra,. Natuurkunde Tijdschrift voor Nederlandsch-Indië. 99(6): 215-296. gs

LeRoy, L. W. (1944b). Miocene foraminifera from Sumatra and Java, Netherlands East Indies, part 1. Miocene foraminifera of central Sumatra, Netherlands East Indies. Colorado School of Mines Quarterly. 39(3): 1-69. gs

Matsui, H. et al. (2016). Changes in the depth habitat of the Oligocene planktic foraminifera (Dentoglobigerina venezuelana) induced by thermocline deepening in the eastern equatorial Pacific. Paleoceanography. 31: 715-731. gs

Molina, E. (1979). Oligoceno-Mioceno inferior por media de foraminiferos planctonicos en el sector central de las Cordilleraa Beticas Espana (Tesis doctoral). . 1-342. gs

Olsson, R. K., Hemleben, C., Huber, B. T. & Berggren, W. A. (2006a). Taxonomy, biostratigraphy, and phylogeny of Eocene Globigerina, Globoturborotalita, Subbotina, and Turborotalita. 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 6): 111-168. 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

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

Quilty, P. G. (1976). Planktonic foraminifera DSDP Leg 34, Nazca Plate. Initial Reports of the Deep Sea Drilling Project. 34: 629-703. gs O

Sanchez, D., Berggren, W. A. & Liska, R. D. (2014). Lower to middle Miocene planktonic and benthic foraminifera from the Carapita Formation, eastern Venezuela Basin and Cipero Formation, southwestern Trinidad. Micropaleontology. 60: 109-174. 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

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

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

Zachariasse, W. J. & Sudijono, (2012). New data of the morphology and classification of the Oligocene-Miocene planktonic foraminifer Paragloborotalia siakensis (LeRoy, 1939). Journal of Foraminiferal Research. 42: 156-168. 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:	4.5-7	N.B. These characters are used for advanced search. N/A - not applicable

Paragloborotalia siakensis

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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