pforams@mikrotax - Morozovella gracilis

Citation: Morozovella gracilis (Bolli 1957)

Basionym: Globorotalia formosa gracilis

Synonyms:

Globorotalia formosa gracilis Bolli, 1957a:75, pl. 18: figs. 4-6 [Globorotalia rex Zone, Trinidad Leasholds, Ltd., well Guayaguayare 159, core 3,707-13', upper Lizard Springs Fm., Trinidad].—Luterbacher, 1964:692, text-fig. 115a-c [topotypes, Globorotalia rex Zone, Trinidad], text-fig. 117a-c [Globorotalia formosa formosalGloborotalia subbotinae Zone, sample level G-58, Gubbio section, central Apennines, Italy], text-fig. 105a-c [Globorotalia velascoensis Zone, Ebano, eastern Mexico, as G. sp. aff. formosa gracilis], text-figs. 106a-107c [Globorotalia velascoensis Zone, sample level G-74, Gubbio section, central Apennines, Italy]. —Shutskaya, 1970b: 118-120, pl. 14: fig. 8a-c [Globorotalia subbotinae Zone, ChurukSu, Kacha River section, Bakhchissaray region, Bakhchissarayan Stage, southwestern Crimea].—Luterbacher, 1975a:727, pl. 2: fig. 7a-c [DSDP Site 313/13/4: 71-73 cm; Mid-Pacific Mountains, North Pacific Ocean]; 1975b:65, pl. 4: figs. 10-12 [Globorotalia subbotinae Zone, Possagno section, Trevisiano Province, Italy],
Globorotalia bollii El-Naggar, 1966:202-203, pl. 22: fig. 6a-d [Globigerina wilcoxensis Zone, Thebes Calcareous Shale, Gebel Aweina, Egypt] [in part, not pl. 22: fig. 5a-d (holotype = M. subbotinae ( Morozova))].
Globorotalia (Morozovella) gracilis Bolli.—Jenkins, 1971:105, pl. 9: figs. 202-204 [Globigerina wilcoxensis Zone, Middle Waipara River section, Waipawan Stage, New Zealand].
Morozovella gracilis (Bolli).—Berggren, 1971b:76, pl. 5: figs. 7, 8 [Morozovella subbotinae Zone, DSDP Hole 20C/5/6: 100-102 cm; South Atlantic Ocean].—Huber, 1991b:440, pl. 4: fig. 8 [Zone AP6A. ODP Hole 738C/10R, 277.78 mbsf; Kerguelen Plateau, southern Indian Ocean].—Lu and Keller, 1995:102. pl. 1: fig. 9 [Zone P6bx of Lu and Keller = Zone P6a this paper; DSDP Site 577/9/6: 53-55 cm; Shatsky Rise, northwestern Pacific Ocean].
Globorotalia (Morozovella) subbotinae gracilis Bolli.—Blow, 1979:1021- 1024, pl. 111: figs. 9, 10, pl. 112: fig. 1 [Zone P7 of Blow, 1979; sample KRE 83F, Moogli Mudstone, Kagua Inlier, Kagua, Papua, New Guinea], pl. 115: figs. 7-10, pl. 223: figs. 3, 4 [Zone P7 of Blow, 1979; sample RS 80, Kilwa area, Tanzania], pl. 120: figs. 1-9, pl. 121: figs. 1-8 [Zone P7 of Blow, 1979; DSDP Hole 47.2/8/3: 83-85 cm; Shatsky Rise, northwestern Pacific Ocean], ? pl. 249: figs. 8, 9 [Globorotalia pseudomenardii Zone, sample/ specimens collected by L .W. LeRoy as topotypic Discorbina simulatilis Schwager, 1883, and presented to R. Wright Barker; Maqfi section, Farafrah Oasis, Egypt].
Morozovella formosa gracilis (Bolli).—Snyder and Waters, 1985:446-447, pl. 8: figs. 7-9 [Zone P7, DSDP Site 549/12/4: 47-50 cm; Pendragon Escarpment, Goban Spur, northeastern Atlantic Ocean],—Toumarkine and Luterbacher, 1985:12, text-fig. 15: 12a-c [reillustration of holotype of Bolli, 1957a]. [Olsson et al. 1999]

Taxonomic discussion: Morozovella gracilis occupies a morphologic/phylogenetic position intermediate between M. subbotinae and M .formosa(see also Pearson,1993).It differs from the former in the increased number of chambers (5-6) in the final whorl, which is associated with a looser (more evolute) coiling mode, and in the elevated spiral intercameral sutures. Morozovella formosa is characterized by a further increase in size and number of chambers (6-8) in the last whorl and concomitant increase in the width of the umbilicus. Like most other morozovellids, particularly those morphotypes closely associated with the aequa -subbotinae -gracilis -marginodentata -formosa plexus, it has a complicated taxonomic history, which is discussed in Berggren (1977) and Blow (1979). Globorotalia bolli El-Naggar (1966), it appears, includes morphotypes of this plexas. We regard his pl. 22: fig. 6a-d as a morphotype of M. gracilis, in contrast to the holotype (pl. 22: fig. 5a-d), which is a morphotype of M. subbotinae. [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. subbotinae but with lower spire and more chambers (5-6).

Description

Planoconvex to moderately biconvex test, with lobulate peripheral margin ornamented with a well developed muricocarina; 5-6 essentially equidimensional chambers in last whorl; umbilical intercameral sutures radial, straight, depressed; on spiral side strongly curved, distinctly muricate except for penultimate/ultimate chamber suture which is straight giving cuneiform shape to final chamber (not unlike the shape in Acarinina triplex); umbilical surface covered with muricae, spiral side weakly muricate except for concentration of muricae along intercameral sutures and peripheral margin of ultimate whorl; small sutural openings along margin/junction of ultimate/penultimate whorl resulting from chamber addition along topographically separated/elevated muricate edges; umbilicus narrow, deep; aperture a low interiomarginal, umbilical-extraumbilical arch extending towards, but not to, the peripheral margin. [Olsson et al. 1999]

Biogeography and Palaeobiology

This is a geographically widespread morphospecies recorded from (predominantly) (sub)tropical biogeographies. It occurs as far south as nearly 60° at ODP Sites 738 (Huber, 1991b) and 747 (Berggren, 1992) on the Kerguelen Plateau, southern Indian Ocean, as part of the earliest Eocene extra-tropical excursion of morozovellids. [Olsson et al. 1999]
Aze et al. 2011 summary: Cosmopolitan; based on Olsson et al. (1999)

No data available. [Olsson et al. 1999]
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts; based on comparison with other species of the genus.

This species evolved from M. subbotinae through a reduction in spire height and an increase in the number of chambers. [Olsson et al. 1999]

Biostratigraphic distribution

Geological Range:
Notes: Zone P5 to Zone P6b. [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): in upper part of E2 zone (60% up, 55.4Ma, in Ypresian stage). Data source: Olsson et al. (1999) f5a

Primary source for this page: Olsson et al. 1999 - Atlas of Paleocene Planktonic Foraminifera, p. 61

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

Berggren, W. A. (1977a). Atlas of Palaeogene Planktonic Foraminifera: some Species of the Genera Subbotina, Planorotalites, Morozovella, Acarinina and Truncorotaloides. In, Ramsay, A. T. S. (ed.) Oceanic Micropaleontology. Academic Press, London 205-300. 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. (1957a). Planktonic foraminifera from the Eocene Navet and San Fernando formations of Trinidad. 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: 155-172. gs

Bolli, H. M. (1957d). The genera Globigerina and Globorotalia in the Paleocene-Lower Eocene Lizard Springs Formation of Trinidad. 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: 61-82. 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. (1971). New Zealand Cenozoic Planktonic Foraminifera. New Zealand Geological Survey, Paleontological Bulletin. 42: 1-278. 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. (1975a). Paleocene and Early Eocene planktonic foraminifera Leg 32, Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 32: 725-728. gs

Olsson, R. K., Hemleben, C., Berggren, W. A. & Huber, B. T. (1999). Atlas of Paleocene Planktonic Foraminifera. Smithsonian Institution Press, Washington, DC. (85): 1-252. gs

Pearson, P. N. (1993). A lineage phylogeny for the Paleogene planktonic foraminifera. Micropaleontology. 39: 193-232. gs

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

Shutskaya, E. K. (1970b). Stratigrafiya, foraminifery i paleogeografiya nizhnego paleogena Kryma, predkavkaz'ya i zapadnoi chadsti srednei azii [Stratigraphy, Foraminifera and Paleogeography of the Lower Paleogene in the Crimea, Precaucasus and the Western Part of Central Asia]. Trudy Vsesoyuznego Neftyanogo Nauchno-Issledovatel'skogo Geologo-Razvedochnogo Instituta (VNIGRI). 70(1): 256-. gs

Snyder, S. W. & Waters, V. J. (1985). Cenozoic planktonic foraminiferal biostratigraphy of the Goban Spur Region, Deep Sea Drilling Project Leg 80. Initial Reports of the Deep Sea Drilling Project. 80: 439-472. gs

Toumarkine, M. & Luterbacher, H. (1985). Paleocene and Eocene planktic foraminifera. In, Bolli, H. M., Saunders, J. B. & Perch-Neilsen, K. (eds) Plankton Stratigraphy. Cambridge Univ. Press, Cambridge 87-154. gs

test outline:	Lobate	chamber arrangement:	Trochospiral	edge view:	Planoconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Petaloid	coiling axis:	Very low	periphery:	Single keel	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 pustulose	shell porosity:	Finely Perforate: 1-2.5µm
umbilical or test sutures:	Strongly depressed	final-whorl chambers:	5-6	N.B. These characters are used for advanced search. N/A - not applicable

Morozovella gracilis

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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