pforams@mikrotax - Morozovella aequa

Citation: Morozovella aequa (Cushman and Renz 1942)

Basionym: Globorotalia crassata aequa

Synonyms:

Globorotalia crassata (Cushman) var. aequa Cushman and Renz, 1942:12, pl. 3: fig. 3a-c [near base Globorotalia subbotinae Zone, Soldado Fm., Trinidad].
Globorotalia lacerti Cushman and Renz, 1946:47, pl. 8: figs. 11, 12 [lower zone of Lizard Springs Fm., Ravine Ampelu, Lizard Springs area, southeastern Trinidad],
Globorotalia (Truncorotalia) crassata (Cushman) var. aequa Cushman and Renz.—Cushman and Bermudez, 1949:37, pl. 7: figs. 7-9 [near San Ramon, about 900 m SW of Carretera San Ramon, Pinar del Rio Province, Cuba; Bermudez Sta. 536].
Globorotalia praenartanensis Shutskaya, 1956:98, pl. 3: fig. 5a-c [Acarinina acarinata Zone, Nal'chik Horizon, lower part of Abazin Formation, Kuban River Basin, central pre-Caucasus].—Luterbacher, 1964:671, text-fig. 73a-c [topotypes from Acarainina acarinata Zone, Kuban River section, northern Caucasus].
Globorotalia aequa Cushman and Renz.—Bolli, 1957a:74,pl. 17: figs. 1-3,pl. 18: figs. 13-15 [Globorotalia velascoensis Zone = Zone P5 this paper; upper Lizard Springs Fm., Trinidad],—Loeblich and Tappan, 1957a: 186, pl. 59: fig. 6a-c [Zone P4, Aquia Fm., Virginia], pl. 64:fig.4a-c [Zone P4, Velasco Fm., Tamaulipas, Mexico] [in part, not pl. 46: figs. 7a-8c (? = M. angulata), pl. 50: fig. 6a-c, pl. 55: fig. 8a-c].—Bolli and Cita, 1960:377, 378, pl. 33: fig. 5a-c [Zone P4, Paderno d'Adda section, northern Italy],—Luterbacher, 1975b:64, pl. 2: figs. 22-24 [Globorotalia subbotinae Zone], pl. 2: figs. 28-30 [Globorotalia pseudomenardii Zone, Possagno section, Treviso Province, northern Italy].
Globorotalia angulata (White).—Loeblich and Tappan, 1957a: 187, pl. 48: fig. 2a-c [Zone P4, Salt Mountain Limestone, Alabama], pl. 58: fig. 2a-c [Aquia Formation, Virginia] [in part, not pl. 45: fig. 7a-c, pl. 50:fig.4a-c, pl. 55: figs. 2a-c, 6a-7c, pl. 64: fig. 5a-c]. [Not White, 1928.]
Globorotalia (Truncorotalia) aequa aequa (Cushman and Renz).— Hillebrandt, 1962:133, 134, pl. 13:fig.la-c [Zone F = Zone P5 this paper, Bad Reichenhall-Salzburg Basin, Austro-German border].
Globorotalia aequa bullata Jenkins, 1966:1110, fig. 10, no. 87-91 [Globigerina triloculinoides Zone, lower Waipawan Stage, Middle Waipara River section, New Zealand]; 1971:100, pl. 7: figs. 172-176 [reillustration of holotype and paratype specimens].
Globorotalia loeblichi El-Naggar, 1966:218-220, pl. 23: fig. la-c [Globigerina wilcoxensis Zone = Zone P6 this paper, sample S 68, Thebes Calcareous Shale, Thebes Fm., Gebel Owaina section].
Truncorotaloides (Morozovella) aequus (Cushman and Renz).—McGowran, 1968:190, pl. 1: figs. 3-7 [Planorotalites simplex Zonule, Boongerooda Greensand, Cape Range, Australia], figs. 8-12 [Truncorotaloides (A.) mckannai Zonule, Boongerooda Greensand, Cape Range, Australia].
Globorotalia (Morozovella) aequa aequa Cushman and Renz.—Jenkins, 1971:100, pl. 7: figs. 167-169 [Globigerina triloculinoides Zone, Middle Waipara River section, New Zealand], figs. 170, 171 [Globigerina triloculinoides Zone, lower part of type Waipawan Stage, Te Uri Stream section, New Zealand],—Blow, 1979:975-977, pl. 96: figs. 4-9, pl. 218: figs. 1-6 [Zone P5 of Blow, 1979; Sample FCRM 1670, Lindi area, Tanzania], pl. 99: fig. 5 [Zone P5 of Blow, 1979; DSDP Hole 47,2/9/1: 64-66 cm; Shatsky Rise, northwestern Pacific Ocean], pl. 102: figs. 6, 9, 10, pl. 103: fig. 1, pl. 211: figs. 3-5 [Zone P6 of Blow, 1979; DSDP Hole 20C/6/3: 76-78 cm; Brazil Basin, South Atlantic Ocean], pl. 118:figs.8-10, pl. 211: figs. 1, 2 [Zone P7 of Blow, 1979; DSDP Hole 47.2/8/3: 83-85 cm; Shatsky Rise, northwestern Pacific Ocean].
Morozovella aequa (Cushman and Renz).—Berggren, 1971 b:76, pl. 5: fig. 6 [Morozovella velascoensis Zone = Zone P5 this paper, DSDP Hole 20C/6/4: 5-7 cm; Brazil Basin, South Atlantic Ocean],—Snyder and Waters, 1985:446, pl. 7: figs. 5-7 [Zone P4/5, DSDP Site 549/16/5: 57-60 cm; Pendragon Escarpment, Goban Spur, northeastern Atlantic Ocean],—[not Lu and Keller, 1995:102, pl. 1: fig. 15 (Zone P3, DSDP Site 577/11/3: 19-21 cm; Shatsky Rise, northwestern Pacific Ocean)].—[not Stott and Kennett, 1990:560, pl. 6: figs. 13-15 (Zone AP 6, ODP Hole 690B/16H/7: 36-40 cm; Maud Rise, Weddell Sea, Southern Ocean (? = Acarinina wilcoxensis))].
Acarinina aequa (Cushman and Renz). —Tjalsma, 1977:508, pl. 3: fig. 13 [Morozovella velascoensis Zone, DSDP Site 329/32/4: 107-109 cm; Maurice Ewing Bank, South Atlantic Ocean].
Globorotalia (Morozovella) aequa lacerti (Cushman and Renz).—Blow, 1979:977-979, pl. 138: figs. 1-3 [Zone P8b of Blow, 1979 = Zone P7 this paper; DSDP Hole 20C/5/5: 72-74 cm; Brazil Basin, South Atlantic Ocean], pl. 115:fig.6 [Zone P7 of Blow, 1979 = Zone P6b this paper; Sample RS 80, Kilwa area, Tanzania, as ex interc G. (A/.) aequa lacerti-G (M.) subbotinae].
Globorotalia (Morozovella) aequa tholiformis Blow, 1979:979-981, pl. 102: figs. 7, 8 [Zone P6 of Blow, 1979; DSDP Hole 20C/6/3: 76-78 cm; Brazil Basin, South Atlantic Ocean], pl. 119: figs. I, 2 [holotype], fig. 3 [Zone P7 of Blow, 1979; DSDP Hole 47.2/8/3: 82-85 cm], pl. 125: figs. 1, 2, pl. 127 figs. 8, 9, pl. 129: fig. 6 [Zone P8a of Blow, 1979; DSDP Hole 47.2/8/2 71-73 cm], pl. 133: fig. 9 [Zone P8b of Blow, 1979; DSDP Hole 47.2/8/1 77-79 cm; Shatsky Rise, northwestern Pacific Ocean], [Olsson et al. 1999]

Taxonomic discussion: This taxon has a complicated and intricate taxonomic history due, in no small part, to the (minor) morphologic variability (and resulting complex nomenclature) ascribed to this species (see discussion by Blow, 1979:975- 982). Cushman and Renz (1942) described a subquadrate, planoconvex, carinate morozovellid from the terminal Paleocene of Trinidad, which has come to serve as the central type of a plexus of late Paleocene to early Eocene forms generally linked by the features listed in the diagnosis above; however, we see little justification, or utility, in using these minor morphologic differences in distinguishing the forms listed in the synonymic list above. [Olsson et al. 1999]

Distinguishing features:
Parent taxon (Morozovella): Test typically plano-convex, chambers strongly anguloconical.
Wall strongly pustulose (muricate) on parts of spire and umbilicus. Most species with muricocarina.
This taxon: Like M. apanthesma but with less chambers (usually 4), more involute coiling (and so a more closed umbilicus) and a peripheral muricocarina.

Description

Biogeography and Palaeobiology

Morozovella aequa is a geographically widespread species, having been recorded from areas circumscribed by latitudes 50°N (Goban Spur, northeastern Atlantic Ocean; Snyder and Waters, 1985) and 50°S (Falkland Plateau; Tjalsma, 1977); it occurs as far south as nearly 60° (Kerguelen Plateau; Berggren, 1992) during the brief early Eocene (Zone P6) temporal excursion of (sub)tropical morozovellids. [Olsson et al. 1999]
Aze et al. 2011 summary: Cosmopolitan; based on Olsson et al. (1999)

Morozovella aequa has more positive ∂13C and more negative ∂18O than Subbotina and Globanomalina and a similar isotopic signature to coexisting morozovellids, such as M. velascoensis (Lu and Keller, 1996; Berggren and Norris, 1997). [Olsson et al. 1999]
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts. Based on very heavy _¹³C and relatively light _¹⁸O. Sources cited by Aze et al. 2011 (appendix S3): Lu & Keller (1996); Berggren & Norris (1997)

Morozovella aequa evolved from M. apanthesma through concomitant reduction in the number of chambers and the development of both more involute coiling (resulting in a more closed umbilicus) and a peripheral muricocarina. We have observed this transition both in our material and particularly at DSDP Site 384, where it occurs at the base of Zone P4c together with the appearance of various acarininid taxa of the soldadoensis and primitiva !coalingensis plexus in the younger part of Chron C25r. We have not found this form in lower parts of the stratigraphic record (cf. Blow, 1979; Lu and Keller, 1995). [Olsson et al. 1999]

Biostratigraphic distribution

Geological Range:
Notes: Zone P4c to Zone P7. [Olsson et al. 1999]
Last occurrence (top): at top of E5 zone (100% up, 50.7Ma, in Ypresian stage). Data source: Olsson et al. (1999) f5a
First occurrence (base): at base of P4c subzone (0% up, 57.8Ma, in Thanetian stage). Data source: Olsson et al. (1999) f5a

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 57

References:

Berggren, W. A. & Pearson, P. N. (2006a). Taxonomy, biostratigraphy, and phylogeny of Eocene Morozovella. 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 11): 343-376. gs O

Berggren, W. A. (1971c). Paleogene planktonic foraminiferal faunas on Legs I-IV (Atlantic Ocean) JOIDES Deep Sea Drilling Program: a synthesis. In, Farinacci, A. (ed.) Proceedings of the Second Planktonic Conference, Roma 1970. Edizioni Tecnoscienza, Rome 57-77. 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

Cushman, J. A. & Bermudez, P. J. (1949). Some Cuban species of Globorotalia. Contributions from the Cushman Laboratory for Foraminiferal Research. 25: 26-45. gs O

Cushman, J. A. & Renz, H. H. (1942). Eocene, Midway, foraminifera from Soldado Rock, Trinidad. Contributions from the Cushman Laboratory for Foraminiferal Research. 18(1): 1-14. gs

Cushman, J. A. & Renz, H. H. (1946). The foraminiferal fauna of the Lizard Springs formation of Trinidad, British West Indies. Cushman Laboratory for Foraminiferal Research, Special Publication. 18: 1-48. gs

El-Naggar, Z. R. (1966). Stratigraphy and planktonic foraminifera of the Upper Cretaceous-Lower Tertiary succession in the Esna-Idfu region, Nile Valley, Egypt, U. A. R. Bulletin of the British Museum (Natural History). supplement 2: 1-291. gs

Hillebrandt, A. , von (1962). Das Paleozän und seine Foraminiferenfauna im Becken von Reichenhall und Salzburg. Abhandlungen Bayerischen Akademie der Wissenschaften. 108: 1-182. 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

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

Luterbacher, H. P. (1964). Studies in some Globorotalia from the Paleocene and Lower Eocene of the Central Apennines. Eclogae Geologicae Helvetiae. 57: 631-730. gs O

Luterbacher, H. P. (1975b). Planktonic Foraminifera of the Paleocene and Early Eocene, Possagno Section. Schweizerische Paläontologische Abhandlungen. 97: 57-67. gs

McGowran, B. J. (1968). Reclassification of Early Tertiary Globorotalia. Micropaleontology. 14: 179-198. gs

Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. 1-252. gs

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

Shutskaya, E. K. (1956). Стратиграфия нижних горизонтов палеогена Центрального Предкавказья по фораминиферам - Stratigraphy of the lower horizons of the Paleogene of the central Precaucasus according to the foraminifera. Maden Tetkik ve Arcana Enstitusu Yayinharindam (Mining Research and Exploration, Institute of Turkey Publ.).. 71(164): 3-119. 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

Tjalsma, R. C. (1977). Cenozoic Foraminifera from the South Atlantic, DSDP Leg 36. Initial Reports of the Deep Sea Drilling Project. 36: 493-518. gs

test outline:	Lobate	chamber arrangement:	Trochospiral	edge view:	Planoconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Petaloid	coiling axis:	Moderate-high	periphery:	Muricocarinate	aperture border:	N/A
umb chbr shape:	Subtriangular	umbilicus:	Narrow	periph margin shape:	Subangular	accessory apertures:	None
spiral sutures:	Raised muricate	umb depth:	Deep	wall texture:	Moderately muricate	shell porosity:	Finely Perforate: 1-2.5µm
umbilical or test sutures:	Moderately depressed	final-whorl chambers:	4-5	N.B. These characters are used for advanced search. N/A - not applicable

Morozovella aequa

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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