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Species Morozovella caucasica Glaessner 1937 | ||||||
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| Diagnosis / Definition: | ||||||
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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). |
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| Discussion / Comments: | ||||||
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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). |
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| Systematics: | ||||||
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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): 1937 Globorotalia aragonensis var. caucasica Glaessner. - Glaessner : p.31 pl 1 fig 6 (type reference)
1985 Morozovella caucasica Glaessner. - Toumarkine & Luterbacher : p.114 figs 16.2-3
Van Eijden & Smit (1991): 1991 Morozovella caucasica Glaessner. - Van Eijden & Smit : p.113
1991 Globorotalia aragonensis var. caucasica Glaessner. - Van Eijden & Smit : p.31 pl. 1, fig. 6
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]
1957 Truncorotalia caucasica Glaessner. - Reiss : p. 239-241 (comments on taxonomy)
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]
1962 Truncorotalia (Truncorotalia) cf. caucasica Glaessner. - Hillebrandt : p. 136-137 pl. 13; fig. 5 [Zone G,
Reichenhall-Salzburg Basin, Germany]
1964 Globorotalia caucasica Glaessner. - Luterbacher : p.684 fig. 97 [Zone of conical globorotaliids, Khieu River, North
Caucasus, Former Soviet Union]
1971 Globorotalia (Morozovella) crater caucasica Glaessner. - Jenkins : p.103 text-fig. 189-191 [G. (M.) crater Zone,
Mangaorapan sample N 14 1/92 1, Waipawa Standard
Section, North Island, New Zealand]
1974 Morozovella aragonensis caucasica Glaessner. - Fleisher : p.1029 pl. 14; fig. 2 [Zone PS, DSDP Site 220, Indian
Ocean]
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]
2006 Morozovella caucasica Glaessner. - Pearson et al. : p.352 pl. 11.4; fig. 1-16
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| References: | ||||||
Glaessner,M.F. (1937): Subbotina,N.N. (1953): Reiss,Z.. (1957): Bykova,N.K.; Vasilenko,V.P..; Voloshinova,N.A..; Myatiliuk,E.V.. and Subbotina,N.N. (1959): Hillebrandt,v.A.. (1962): Luterbacher,H.P. (1964): Jenkins,D.G. (1971): Fleisher,R.L. (1974): Luterbacher,H.P. (1975): Stainforth,R.M.; Lamb,J.L.; Luterbacher,H.P.; Beard,J.H. and Jeffords,R.M. (1975): Blow,W.H. (1979): Toumarkine,M. and Luterbacher,H.P. (1985): Van Eijden,A.J.M. and Smit,J. (1991): Pearson,P.N.; Olsson,R.K.; Hemleben,C.; Huber,B.T. and Berggren,W.A. (2006): |
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| Anonymous: Unedited TaxonConcept data | ||||||
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