pforams@mikrotax - Morozovella caucasica

Citation: Morozovella caucasica (Glaessner 1937)

Basionym: Globorotalia aragonensis caucasica

Synonyms:

Globorotalia aragonensis Nuttall var. caucasica Glaessner, 1937:31 (English):48 (Russian), pl. 1, figs. 6a-c [lower Eocene upper beds of the lower part of the Lower Foraminiferal (Koun) Fm., Il’skaya, north west Caucasus, Former Soviet Union].
Truncorotalia caucasica (Glaessner).—Reiss, 1957:239-241 (comments on taxonomy). —Bykova, Vasilenko, Voloshinova, Myatliuk and Subbotina, 1959:302-303, text-figs. 691A-C (reillustration of Subbotina, 1953, pl. 19, figs. 2a-c) [Zone of conical globorotaliids, Kuban River section, Foraminiferal Beds, Green Fm., North Caucasus, Former Soviet Union].
Truncorotalia (Truncorotalia) cf. caucasica Glaessner.—von Hillebrandt, 1962:136-137, pl. 13: fig. 5 [Zone G, Reichenhall-Salzburg Basin, Germany].
Globorotalia caucasica Glaessner—Luterbacher, 1964:684, fig. 97 [Zone of conical globorotaliids, Khieu River, North Caucasus, Former Soviet Union].—Stainforth and others, 1975:175-176, text-fig. 41: 1-2 (1: from Subbotina, 1953:19, figs. 1a-c; fig. 2 ascribed incorrectly to Subbotina, 1953), pl. 19, fig. 2 (it is actually fig. 3 and indicated as transitional to aragonensis); 41: 3-6 [lower Eocene G. pentacamerata Zone, northern Caucasus, former Soviet Union].—Luterbacher, 1975b:66, pl. 4, figs. 28-30 [Globorotalia pentacamerata Zone, Possagno section, Italy].
Globorotalia (Morozovella) crater caucasica Glaessner.— Jenkins, 1971:103, text-figs. 189-191 [G. (M.) crater Zone, Mangaorapan sample N141/921, Waipawa Standard Section, North Island, New Zealand].
Morozovella aragonensis caucasica (Glaessner).—Fleisher, 1974:1029, pl. 14: fig. 2 [Zone P8, DSDP Site 220, Indian Ocean].
Globorotalia (Morozovella) caucasica Glaessner.—Blow, 1979:993, pl. 146: figs. 3 and 4 [Zone P9, DSDP Hole 47.2, Shatsky Rise, northwest Pacific Ocean]; pl. 147: figs. 9, 10; pl. 226: fig. 1; pl. 152: figs. 6-9; pl. 226: fig. 2; pl. 226: figs. 3,4 [Zone P9, Kane 9-C piston core, North Atlantic Ocean].
Morozovella caucasica (Glaessner).—Toumarkine and Luterbacher, 1985:114, figs. 16.2-3 [2: from Subbotina, 1953, pl. 19: fig. 1; 3: holotype reillustrated].
Globorotalia velascoensis (Cushman). —Subbotina, 1953:216-219, pl. 19, figs. 1-2 [Zone of conical globorotaliids, Foraminiferal beds, Green Fm., Kuban River section, North Caucasus, Former Soviet Union]; fig. 3 [Zone of conical globorotaliids, Kutais Horizon [F3], Foraminiferal Beds, Gubs River section, Barakaev region, North Caucasus, Former Soviet Union]. [Not Cushman, 1925.]

Taxonomic discussion: There exists a variety of opinions on the phylogenetic affinities of this taxon which may be summarized as follows:
1. Although Glaessner (1937) clearly distinguished between his new taxon caucasica (early Eocene) and velascoensis Cushman (late Paleocene), the two forms were frequently confused in the literature (see
Subbotina, 1953 and El Naggar,1966, for example) as well as aragonensis and caucasica (identified as velascoensis; Subbotina, 1947; see Subbotina, 1953, p. 216). It was Reiss (1957; see also Blow, 1979) who provided clear differentiation of the two morphotypes on the basis of morphology and stratigraphic distribution. Indeed, one of us (WAB) pointed out this differentiation to Subbotina during a visit to VNIGRI (St. Petersburg) in 1958 and by the late 1950s Subbotina had incorporated the distinction between the two as shown by the correct identification of caucasica in the Soviet Treatise on Paleontology (Bykova and others, 1959).
2. Hillebrandt (1962) included crater Finlay and formosa Bolli in the synonomy of caucasica and considered it to have evolved from G. (T.) aequa simulatilis (see Berggren and Norris, 1997, p. 78 for a discussion of the probable/possible taxonomic affinities of the late Paleocene taxon simulatilis).
3. The holotype of Globorotalia crater Finlay is a 5-chambered morphotype similar in several respects to caucasica. Hornibrook (1958) drew attention to the “wide umbilicus surrounded by strongly muricate (not true spines) distal ends of chambers” as characteristic of crater. Jenkins (1971) considered M. caucasica a subspecies of crater and to differ only in the number of chambers ( 6-8 vs. 5) from the latter. Like Hillebrandt (1962), Jenkins (1971) considered formosa a junior synonym of crater.
4. Stainforth and others (1975) considered that crater is possibly a “highly ornamented member of the Globorotalia formosa formosa plexus and G. caucasica is a homeomorph originating from Globorotalia aragonensis with which it is linked by transitional forms”. In support of this view Stainforth and others (1975) observed that in New Zealand G. crater is used to delineate a zone which extends over/correlates with the G. formosa formosa, G. aragonensis and G. pentacamerata Zones, that is, a zone which extends below the base of the typical 6-8 chambered caucasica. 5. Blow (1979) extended these views in separating crater (5-chambered) and caucasica (6-8 chambered; see also Fleisher, 1974, pl. 14, fig. 2 who illustrated a morphotype with apparently 9 or 10 chambers from Zone P11 of the Indian Ocean) on the basis of chamber number and the narrower umbilicus of crater. He asserted that crater lies much closer to the caucasica end of the lensiformis-crater -caucasica lineage than it does to the ancestral lensiformis morphotype, a view with which we can readily agree. Thus, Blow (1979) considered crater as a form transitional between lensiformis and caucasica with typical 5-chambered morphotypes extending into horizons as high as Zone P10 (middle Eocene). Morozovella twisselmanni (Mallory) was considered a junior synonym of crater as well. However, Blow (1979) also illustrated several morphotypes which he attributed to crater but which also bear a close resemblance to formosa Bolli: 5-6 chambers, narrow umbilicus, absence of circumumbilical muricate ornament ( see for instance forms which he considered typical of crater by comparison with paratypes of crater; Blow, 1979, pl. 138, figs. 4-8).
6. Several authors have considered a phylogenetic relationship between aragonensis and caucasica more likely (Fleisher, 1974; Berggren 1977; Toumarkine and Luterbacher, 1985). Our own studies suggest that caucasica is, indeed, more closely related to crater and that it represents the end member of the subbotinae -lensiformis-crater -caucasica lineage, whereas aragonensis is the end member of a divergent M. subbotinae -lensiformis -aragonensis lineage. [Berggren & Pearson 2006]

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. crater but more strongly planoconical test with more chambers (usually 6-8) in the final whorl; umbilicus wider, and circumumbilical chamber margins strongly ornamented by fused muricae.
It is strongly homeomorphic with M. velascoensis from the late Paleocene-early Eocene (Zone P3b-E2).

Description

Test subcircular, moderately lobulate peripheral outline, planoconvex; chambers triangular on umbilical side, trapezoidal to subquadrate on spiral side as a function of degree of curvature of intercameral sutures; wall surface normal perforate, nonspinose; muricae strongly developed on circumumbilical collar; primary aperture a low umbilical-extraumbilical slit extending to peripheral margin; sutures depressed, straight, radial; umbilicus large, deep surrounded by steeply plunging circumumbilical chamber walls and surmounted by thickly ornamented circumumbilical collar of fused muricae which rim the everted margins of the chambers; in spiral view 15-18 chambers arranged in approximately 3 whorls; early chambers slightly raised above test surface; gradual increase in chamber size throughout; muricate sutures strongly curved, flush with/slightly elevated above test surface; in edge view umbilicoconvex; spiral side flat or nearly so; strongly muricate/beaded keel. [Berggren & Pearson 2006]

Muricate, nonspinose, normal perforate. [Berggren & Pearson 2006]

Holotype dimension(s): not given; range given: 0.4-0.6 mm (diameter). [Berggren & Pearson 2006]

Biogeography and Palaeobiology

Widely distributed in (sub)tropical-Tethyan regions; particularly common in the Aquitaine Basin (France), the Indo-Pacific region, among others. [Berggren & Pearson 2006]
Aze et al. 2011 summary: Low latitudes; based on Berggren & Pearson (2006)

No data available. [Berggren & Pearson 2006]
Aze et al. 2011 ecogroup 1 - Open ocean mixed-layer tropical/subtropical, with symbionts; based on comparison with other species of the genus.

This taxon is the end member of the M. subbotinae -lensiformis-crater -caucasica lineage and does not appear to have left any descendants. It is strongly homeomorphic with, but unrelated in terms of lineal descent to, M. velascoensis. [Berggren & Pearson 2006]

Most likely ancestor: Morozovella crater - at confidence level 4 (out of 5). Data source: Berggren & Pearson (2006) f11.1.

Biostratigraphic distribution

Geological Range:
Notes: Zone E6 to Zone E8. [Berggren & Pearson 2006]
Last occurrence (top): in mid part of E8 zone (50% up, 44.8Ma, in Lutetian stage). Data source: Berggren & Pearson (2006) f11.1
First occurrence (base): at base of E6 zone (0% up, 50.7Ma, in Ypresian stage). Data source: Berggren & Pearson (2006) f11.1

Primary source for this page: Berggren & Pearson 2006 - Eocene Atlas, chap. 11, p. 354

References:

Berggren, W. A. & Norris, R. D. (1997). Biostratigraphy, phylogeny and systematics of Paleocene trochospiral planktonic foraminifera. Micropaleontology. 43(supplement 1): 1-116. gs

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. (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

Cushman, J. A. (1925e). Some new foraminifera from the Velasco shale of Mexico. Contributions from the Cushman Laboratory for Foraminiferal Research. 1(1): 18-23. gs

Fleisher, R. L. (1974a). Cenozoic planktonic foraminifera and biostratigraphy, Arabian Sea, Deep Sea Drilling Project, Leg 23A. Initial Reports of the Deep Sea Drilling Project. 23: 1001-1072. gs O

Glaessner, M. F. (1937a). Planktonforaminiferen aus der Kreide und dem Eozän und ihre stratigraphische Bedeutung. Etyudy po Mikropaleontologiy, Paleontologicheskaya Laboratoriya Moskovskogo Gosudarstvennogo Universiteta. 1(1): 27-46. 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

Hornibrook, N. d. B. (1958). New Zealand Upper Cretaceous and Tertiary foraminiferal zones and some overseas correlations. Micropaleontology. 4: 25-38. 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. (1975b). Planktonic Foraminifera of the Paleocene and Early Eocene, Possagno Section. Schweizerische Paläontologische Abhandlungen. 97: 57-67. gs

Reiss, Z. (1957a). Notes on foraminifera from Israel. 1. Remarks on Truncorotalia aragonesis caucasica (Glaessner). 2. Loxostomoides, a new late Cretaceous and early Tertiary genus of foraminifera. 3. Sigalia, a new genus of foraminifera. Bulletin Research Council of Israel (Reprinted In Israel Geological Survey Bulletin). 6B: 239-244. 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:	Subcircular	chamber arrangement:	Trochospiral	edge view:	Planoconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Crescentic	coiling axis:	High	periphery:	Single keel	aperture border:	N/A
umb chbr shape:	Subtriangular	umbilicus:	Wide	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:	5-9	N.B. These characters are used for advanced search. N/A - not applicable

Morozovella caucasica

Taxonomy

Description

Biogeography and Palaeobiology

Biostratigraphic distribution

References:

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