Morozovella formosa Bolli 1957 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 formosa Bolli 1957 |
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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, inflated and subangular on umbilical side;
trapezoidal with curved margins on spiral side; 15-1 8
chambers arranged in approximately 3 whorls on spiral
side and generally 6-6 1/2 chambers (rarely 7-8) in final
whorl on umbilical side with muricae scattered on early
chambers of last whorl; sutures moderately depressed,
weakly curved (early chambers) to straight, radial (later
chambers) on last whorl; umbilicus open, moderately
wide, deep; primary aperture a low umbilical- extraumbilical arch extending to peripheral margin;
gradual increase in chamber size throughout although
last 2-3 chambers exhibit varying size; muricate sutures
strongly curved, flush with/slightly elevated above test
surface; umbilico-convex in edge view; spiral side flat
or nearly so; strongly muricate keel.
Size: Dimensions of holotype: maximum
diameter: 0.65 mm. |
Discussion / Comments: |
Pearson et al. (2006):
DISTINGUISHING FEATURES.-
This taxon is
characterized by its relatively large, robust test, 6-7
(rarely 8) chambers and strongly muricate keel. It is
distinguished from its antecedent M. gracilis by its larger,
more robust test, larger number of chambers in the last
whorl and wider umbilicus, and from its partially
contemporaneous homeomorph, M. crater, by its more
lobulate periphery and larger number of chambers in the
final whorl and less ornamentgd test.
DISCUSSION.-
Blow (1979, p. 1000, 1001) drew
attention to the fact that formosa and the crater-
caucasica complex, while seemingly morphologically
distinct when treated as isolated individuals, in fact
require close scrutiny in order to retain the
biostratigraphic utility of both. He further pointed out
the gross homeomorphy between formosa and some
morphotypes of the older velascoensis. Finally he
observed that some of the phylogenetically advanced
morphotypes of the velascoensis and the lensiformis-
crater-caucasica "gens" exhibit features in common with
formosa; a sort of "threefold homeomorphy" as he
dubbed it. Distinction among the different morphotypes
was made on the following basis:
l. formosa is flat to slightly convex in dorsal
(spiral) aspect with chambers somewhat longer (anterio-
posteriorly) tangentially than broad radially.
2. formosa has dorsal /spiral intercameral sutures
nearly radial proximally but recurved (but not sharply
retorse) near periphery.
3. velascoensis has chambers in dorsal/spiral
aspect nearly equidimensional and spiral intercameral
sutures exhibit retorse distal part.
4. In axial-apertural view anguloconical angle
in formosa is markedly acute (- 45°), whereas in
velascoensis it is nearly a right-angle (- 80-85°); the
umbilico-peripheral part of chamber is often somewhat
concave in the area between the peripheral test muricocarina and the "horn-like", adumbilically pointed
umbilical shoulders.
5. Whereas the anguloconical angle in the
crater-caucasica group is comparable to that in formosa,
the earlier chambers have a more rounded appearance
in axialledge view.
6. The umbilicus in formosa is wide and the
angle made by the junction of the chamber walls interior
and exterior to the umbilicus is on the order of - 40-45°;
in crater this angle is - 60-60° in the case of the earlier
chambers and the umbilical shoulders are more gently
rounded, only the last 2-3 chambers exhibiting a strongly
reflexed angle between interior and exterior chamber
walls.
7. The main distinguishing feature separating
fomosa from the other forms above is the nature of the
early vorticifonn spiral intercameral sutures together
with the acute conical angle and the distinctly flat spiral
side.
PHYLOGENETIC RELATIONSHIPS.-
This taxon
evolved from M. gracilis and does not appear to have
left any descendants.
STRATIGRAPHIC RANGE.-
Base of Zone E4 (by
definition) to top of Zone E6 (by definition).
GEOGRAPHIC DISTRIBUTION.-
Widely distributed
in (sub)tropical regions (Caribbean Sea, Atlantic, Pacific,
Tethyan, Indian and Austral Oceans).
STABLE ISOTOPE PALEOBIOL0GY.-
No data
available. |
Systematics: |
1 Superregnum Eukaryota
Regnum Protoctista
Phylum Ciliophora
Subphylum Postciliodesmatophora
Ordo Globigerinida
Superfamilia Globorotaliaceae
Superfamilia Nonionacea
Familia Truncorotaloididae
Genus Morozovella
Species Morozovella formosa
35 Ordo Foraminiferida
Superfamilia Globigerinaceae
Familia Truncorotaloididae
Genus Morozovella
Species Morozovella formosa
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Synonym list: |
Pearson et al. (2006):
? 1946 Globorotalia velascoensis Cushman. - Cushman & Renz : p.47 pl. 8; fig. 13-14 [upper Lizard Springs Fm.,
Trinidad; see Renz, 195 1 for corrected figure explanation];
[Not Cushman, 1925]
1957 Globorotalia formosa formosa Bolli. - Bolli : p.76 pl. 18; fig. 1-3 [lower Eocene G. formosa formosa Zone, upper Lizard
Springs Fm., Trinidad]
1964 Globorotalia formosa formosa Bolli. - Luterbacher : P: 694-696 text-fig. 118a-c [G. formosa formosa Zone, upper Lizard Springs Fm., Trinidad];
text-fig. 119a-c [C. formosa formosa/G. subbotinae Zone, Gubbio section, Central Apennines, Italy];
text-fig. 120a-122c [C. aragonensis Zone, Gubbio section, Italy]
1971 Morozovella formosa Bolli. - Berggren : pl. 5; fig. 15, 16 [Zone P6b, DSDP Hole 20C, South Atlantic Ocean]
1975 Globorotalia formosa formosa Bolli. - Stainforth et al. : p.184 text-fig. 48.1-5 [G. formosa formosa Zone, Lodo Fm., California];
text-fig. 48.6 [reillustration of holotype from Bolli, 1957b, pl. 18, figs. l-3]
1979 Globorotalia (Morozovella) formosa Bolli. - Blow : p.1000 pl. 127, fig. 3 and 4 [Zone P8a, DSDP Hole 47.2, Shatsky Rise, northwest Pacific Ocean];
pl. 134, fig. 7, 8;
pl. 224, fig. 4 [Zone P8b, DSDP Hole 47.2, Shatsky Rise, northwest Pacific Ocean];
pl. 138, fig. 9, 10;
pl. 224, fig. 3 [Zone P8b, DSDP Hole 20C, South
Atlantic Ocean]
2000 Morozovella formosa formosa Bolli. - Warraich et al. : p.293 fig. 17.21-23 [Zone P7, Dungan Fm., Rakhi
Nala section, Sulaiman Range, Pakistan]
2001 Morozovella formosa formosa Bolli. - Warraich & Ogasawara : p.39 fig. 9.13-15 [Zone P7, Dungan
Fm., Rakhi Nala section, Sulaiman Range, Pakistan]
2006 Morozovella formosa Bolli. - Pearson et al. : p.359 pl. 11.7; fig. 1-16 (Pl. 11.7, Figs. 1-3: new SEMs of holotype of
Globorotalia formosa formosa Bolli)
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Stratigraphy - absolute ages: |
FAD: 54 ± 0 [Ma], Corfield (1987)
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Specimen: |
Smithsonian Museum of Natural History, Washington, D.C., Inventory number: USNM P5056
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References: |
Cushman,J.A. and Renz,H.H. (1946): The Foraminiferal Fauna of the Lizard Springs Formation of Trinidad, British West Indies . Cushman Laboratory for Foraminiferal Research, Special Publication Vol. 18 p. 1-48
Bolli,H.M. (1957): The genera Globigerina and Globorotalia in the Paleocene-Lower Eocene Lizard Springs Formation of Trinidad, B.W.I . Bulletin of the U.S. National Museum Vol. 215 p. 61-82
Bermudez,P.J. (1961): Contribucion al estudio de las Globigerinidea de la region Caribe-Antillana (Paleocene-Reciente). In: Boletino Geologia (Venezuela), Special Publicacion Vol. 3
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
Samanta,B.K. (1970): Middle Eocene Planktonic Foraminifera from Lakhpat, Cutch, Western India . Micropaleontology Vol. 16
Berggren,W.A. (1971): Paleogene Planktonic Foraminiferal Faunas on Legs I-IV (Atlantic Ocean), JOIDES Deep Sea Drilling Program- a Synthesis. In: Proceedings of the II Planktonic Conference. Rome, Edizioni Tecnoscienza Vol. 1 Eds: Farinacci, A. p. 57-77
Postuma,J.A. (1971): Manual of Planktonic Foraminifera. p. 422 pp
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
Corfield,R.M. (1987): Patterns of evolution in Paleocene and Eocene planktonic Foraminifera. In: The Micropaleontology of Carbonate Environments
Warraich,M.Y..; Ogasawara,K.. and Nishi,H.. (2000): Late Paleocene to early Eocene planktonic foraminiferal biostratigraphy of the Dungan Formation, Sulaiman Range, Central Pakistan . Paleontological Research Vol. 4 p. 275-301
Warraich,M.Y.. and Ogasawara,K.. (2001): Tethyan Paleocene-Eocene planktic foraminifera from the Rakhi Nala and Zinda Pir land sections of the Sulaiman Range, Pakistan . Science Reports of the Institute of Geoscience University of Tsukuba, section B Vol. 22 p. 1-59
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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