Morozovella caucasica Glaessner 1937 from: Pearson, P.N.Olsson, R.K.Hemleben, C.Huber, B.T.Berggren, W.A. (2006): Atlas of Eocene Planktonic Foraminifera. p. 1-513 . |
Notice: This catalogue page may contain unedited data.
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Species Morozovella caucasica Glaessner 1937 |
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Diagnosis / Definition: |
Pearson et al. (2006):
DESCRIPTION.
Type of wall: Muricate, nonspinose, normal
perforate.
Test morphology: 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; 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 15-1 8 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 muricatel
beaded keel.
Size: Holotype dimension(s): not given; range
given: 0.4-0.6 mm (diameter). |
Discussion / Comments: |
Toumarkine & Luterbacher (1985):
The conicotruncate test is strongly ornamented with a heavy 'keel' and bundles of spines on the umbilical shoulders and is an Early Eocene homeomorph of the Late Paleocene Morozovella velascoensis.
The last whorl is composed of 5 to 8 chambers which increase regularly in size. The umbilicus is wide and deep.
Single specimens of Morozovella velascoensis and M. caucasica are often virtually identical but can be distinguished by the co-occurrence of transitional forms to M. acuta and M. aragonensis respectively.
Van Eijden & Smit (1991):
Remarks. The encountered specimens show only a weak ornamentation and are thus intermediate with M. aragonensis (Nuttall, 1930). This species is a good indicator of the upper part of the lower Eocene and the
lowermost middle Eocene.
Pearson et al. (2006):
DISTINGUISHING FEATURES.-
This taxon is
characterized by having a strongly planoconical test with
6-8 (less commonly 5 at one extreme and 9-10 at the
other) chambers in the final whorl, a large open and deep
umbilicus whose everted circumumbilical chamber
margins are strongly ornainented by fused muricae. It is
strongly homeomorphic with M. velascoensis from the
late Paleocene-early Eocene (Zone P3b-E2), but M.
velascoensis s.s. may be distinguished by its (generally)
somewhat larger size, higher conical angle and more
pronounced circumumbilical ornament of everted
chamber shoulders (tips).
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 hequently confused in the literature (see Subbotina, 1953 and El Naggar,1966, for example) as
well as aragonensis and caucusica (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 (1 962) 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 probablelpossible taxonomic affinities
of the late Paleocene taxon sirnulatilis).
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 (1 971) 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 P1 1 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, 1 985).
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.
PHYLOGENETIC RELATIONSHIPS.-
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.
STRATIGRAPHIC RANGE.-
Zone E6 to Zone E8.
GEOGRAPHIC DISTRlBUTI0N.-
Widely distributed
in (sub)tropical-Tethyan regions; particularly common
in the Aquitaine Basin (France), the Indo-Pacific region,
among others.
STABLE ISOTOPE PALEOBIOLOGY.-
No data
available.
REPOSITORY.-
Holotype may have been deposited
in the collections of the Paleontology Department,
University of Moscow; not seen during visits in 1962,
1973 and 1988 (WAB). |
Systematics: |
15 Classis Foraminifera
Genus Morozovella
Species Morozovella caucasica
32 Ordo Foraminiferida
Familia Globorotaliidae
Genus Morozovella
Species Morozovella caucasica
35 Ordo Foraminiferida
Superfamilia Globigerinaceae
Familia Truncorotaloididae
Genus Morozovella
Species Morozovella caucasica
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Synonym list: |
Toumarkine & Luterbacher (1985):
Van Eijden & Smit (1991):
Pearson et al. (2006):
1937 Globorotalia aragonensis var. caucasica Glaessner. - Glaessner : p. 31 (English), 48 pl. 1; fig. 6a-c [lower
Eocene upper beds of the lower part of the Lower
Foraminiferal (Koun) Fm., Il'skaya, north west Caucasus,
Former Soviet Union]
1953 Globorotalia velascoensis Cushman. - Subbotina : p. 216-219 pl. 19, fig. 1-2 [Zone of conical globorotaliids, Foraminiferal beds, Green Fm., Kuban River section, North Caucasus, Forrncr 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]
1959 Truncorotalia caucasica Glaessner. - Bykova et al. : p. 302-303 text-fig. 691A-C (reillustration of Subbotina, 1953, pl. 19, fig. 2a-c) [Zone of conical globorotaliids, Kuban River
section, Foraminiferal Beds, Green Fm., North Caucasus,
Former Soviet Union]
1964 Globorotalia caucasica Glaessner. - Luterbacher : p.684 fig. 97 [Zone of conical globorotaliids, Khieu River, North
Caucasus, Former Soviet Union]
1975 Globorotalia caucasica Glaessner. - Stainforth et al. : p. 175-176 text-fig. 41.1-2 (1: from Subbotina,
1953, pl. 19, fig. la-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]
1975 Globorotalia caucasica Glaessner. - Luterbacher : p.66 pl. 4; fig. 28-30 [Globorotalia pentacamerata Zone, Possagno
section, Italy]
1979 Globorotalia (Morozovella) caucasica Glaessner. - Blow : p.993 pl. 146, fig. 3 and 4 [Zone P9, DSDP Hole
47.2, Shatsky Rise, northwest Pacific Ocean];
pl. 147, fig. 9, 10;
pl. 226, fig. 1;
pl. 152, fig. 6-9;
pl. 226, fig. 2;
pl. 226, fig. 3,4 [Zone P9, Kane 9-C piston core, North Atlantic Ocean]
1985 Morozovella caucasica Glaessner. - Toumarkine & Luterbacher : p.114 fig. 16.2-3 [2: from Subbotina, 1953, pl. 19,
fig. 1, 3; holotype reillustrated]
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References: |
Glaessner,M.F. (1937): Planktonische Foraminiferen aus der Kreide und dem Eozän und ihre stratigraphische Bedeutung. In: Studies in Micropaleontology Vol. 1(1) p. 27-46
Subbotina,N.N. (1953): Iskopaemye foraminifery SSSR (Globigerinidy, Khantkenininidy i Globorotaliidy) . Trudy Vsesoyznogo Nauchno-Issledovatel'skogo Geologo-razvedochnogo Instituta (VNIGRI) Vol. 76 p. 296
Reiss,Z.. (1957): Notes on Foraminifera from Israel: 1. Remarks on Truncorotalia aragonensis caucasica (Glaessner) . Bulletin Research Council of Israel (Reprinted in Israel Geological Survey Bulletin, No. 9, p. iiii).6B p. 239-241
Bykova,N.K.; Vasilenko,V.P..; Voloshinova,N.A..; Myatiliuk,E.V.. and Subbotina,N.N. (1959): Rotaliidac. In: Osnovyie Paleontologii: Obsschaya chast, Prosteishie Eds: Rauser-Chernoussova, D.M..Fursenko, A.V.. p. 265-307
Hillebrandt,v.A.. (1962): Das Paleozän und seine Foraminiferenfauna im Becken von Reichenhall und Salzburg . Bayerische Akademie Wissenschaft, Mathematischen-Naturwissenschaften Klasse Vol. 108 p. 188 p.
Luterbacher,H.P. (1964): Studies in some Globorotalia from the Paleocene and Lower Eocene of the Central Apennines . Ecoglae geologicae Helvetiae Vol. 57 p. 631-730
Jenkins,D.G. (1971): New Zealand Cenozoic Planktonic Foraminifera . New Zealand Geological Survey Paleontological Bulletin Vol. 42
Fleisher,R.L. (1974): Cenozoic planktonic foraminifera and biostratigraphy, Arabian Sea, Deep Sea Drilling Project, Leg 23A. In: Initial Reports of the Deep Sea Drilling Project Vol. 23 Eds: Whitmarsh, R.B.Weser, O.E.Ross, D.A. p. 1001-1072
Luterbacher,H.P. (1975): Planktonic Foraminifera of the Paleocene and Early Eocene, Possagno Section. . Schweizerische Palantologische Abhandlungen Vol. 97 p. 57-67
Stainforth,R.M.; Lamb,J.L.; Luterbacher,H.P.; Beard,J.H. and Jeffords,R.M. (1975): Cenozoic planktonic foraminiferal zonation and characteristics of index forms . Paleontological ContributionsArticle 62 p. 425
Blow,W.H. (1979): The Cainozoic Globigerinida. 3 Vols p. 1413 pp
Toumarkine,M. and Luterbacher,H.P. (1985): Paleocene and Eocene Planktic Foraminifera. In: Plankton Stratigraphy p. 87-154
Van Eijden,A.J.M. and Smit,J. (1991): Eastern Indian Ocean Cretaceous and Paleogene quantitative biostratigraphy. In: Proceedings of the Ocean Drilling Program, Scientific Results Vol. 121 Eds: Weissel, J.Peirce, J.Taylor, E.Alt, J. p. 77-123
Pearson,P.N.; Olsson,R.K.; Hemleben,C.; Huber,B.T. and Berggren,W.A. (2006): Atlas of Eocene Planktonic Foraminifera. p. 1-513
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