Turborotalia cunialensis Toumarkine & Bolli 1970 from: Pearson, P.N.Chaisson, W.P. (1997): Late Paleocene to middle Miocene planktonic foraminifer biostratigraphy of the Ceara Rise. Vol. 154 Eds: Leckie, R.M.Sigurdsson, H.Acton, G.D.Draper, G. . |
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Species Turborotalia cunialensis Toumarkine & Bolli 1970 |
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Diagnosis / Definition: |
Pearson et al. (2006):
DISCRIPTION.-
Type of wall: Smooth, normal perforate; tendency to defoliate (e.g. Snyder and Waters, 1985).
Test morphology: Low trochospiral, dorsoventrally strongly compressed biconvex test with 4-5 chambers in the final whorl; most specimens show imperforate keel around periphery, which can be distinctly raised; chambers appressed and embacing, wedge-shaped in ventral aspect and increasing moderately in size; final chamber distinctly acute (<40°)at periphery in edge view; dorsal sutures strongly curved, flat or raised with imperforate band; aperture a broad arch, sometimes almost circular, in extraumbilical position; umbillicus very narrow; ventral sutures moderately curved, depressed. Strong tendency for sinistral coiling.
Size: Holotype lenght 0.45 mm. |
Discussion / Comments: |
Pearson & Chaisson (1997):
Turborotalia cunialensis is the final compressed, keeled morphospecies belonging to the Turborotalia cerroazulensis lineage.
Pearson et al. (2006):
DISTINGUISHING FEATURES.-
Turborotalia cunialensis is ditinguished from T. cocoaensis by its even more acute periphery to the final chamber as seen in edge view, and the biconvex morphology.
These characters, rather than the presence or absence of a keel, are most reliable in distinguishing the morphospecies.
DISCUSSION.-
Turborotalia cunialensis, as strictly defined, is very rare, although specimens of T. cocoaensis that show some transition towards it, either in having a moderately acute periphery or an impel for ate band (e.g., pl. 15.4, Fig. 17) are more common. Toumarkine and Luterbacher (1985) attributed its rarity to its tendency to dissolve more easily than other species of
Turborotalia, but this has yet to be demonstrated.
Possibly T. cunialensis was more restricted to tropical
latitudes than the other species.
PHYLOGENETIC RELATIONSHIPS .-
Evolved from
Turborotalia cocoaensis in the upper Eocene
(Toumarkine and Bolli, 1970).
STRATIGRAPHIC RANGE.-
Upper Eocene, Zone E16, disappearing just below the Eocene/Oligocene boundary (Toumarkine and Bolli, 1970; Coccioni and others, 1988). The apparent diachroneity of the first occurrence of this species is probably related to inconsistencies in recognizing it.
GEOGRAPHIC DISTRIBUTION.-
Cosmopolitan,
possibly more restricted to tropical latitudes than T.
cerroazulensis.
STABLE ISOTOPE PALEOBIOL0GY.-
No data
available. |
Systematics: |
1 Superregnum Eukaryota
Regnum Protoctista
Phylum Ciliophora
Subphylum Postciliodesmatophora
Ordo Globigerinida
Superfamilia Globorotaliaceae
Superfamilia Nonionacea
Familia Globorotaliidae
Genus Turborotalia
Species Turborotalia cunialensis
32 Ordo Foraminiferida
Familia Globorotaliidae
Genus Turborotalia
Species Turborotalia cunialensis
35 Ordo Foraminiferida
Superfamilia Globigerinaceae
Familia Hedbergellidae
Genus Turborotalia
Species Turborotalia cunialensis
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Synonym list: |
Pearson & Chaisson (1997):
Van Eijden & Smit (1991):
Pearson et al. (2006):
1978 Globorotalia cerroazulensis cunialensis Toumarkine & Bolli. - Toumarkine : p.712 pl. 7; fig. 1-12 [upper Eocene Globigerinatheka semiinvoluta
Zone, DSDP Site 363, Walvis Ridge, South
Atlantic Ocean]
1988 Turborotalia cunialensis Toumarkine & Bolli. - Coccioni et al. : pl. 1; fig. 7-9 [upper Eocene Zone P16, Massignano, Italy]
2006 Turborotalia cunialensis Toumarkine & Bolli. - Pearson et al. : p.444 pl. 15.4; fig. 13-17 (PI. 15.4, Fig. 13: holotype of Globorotalia
cerroazulensis cunialensis Toumarkine and Bolli,
reillustrated);
(PI. 15.4, Fig. 14: paratype of Globorotalia
cerroazulensis cunialensis Toumarkine and Bolli,
reillustrated)
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Stratigraphy - absolute ages: |
FAD: 35.2 ± 0 [Ma], Berggren et al. (1995)
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Specimen: |
Museum d'Histoire Naturelle de Bale, Inventory number: C26602
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References: |
Toumarkine,M. and Bolli,H.M. (1970): Evolution de Globorotalia cerroazulensis (Cole) dans l'Eocene moyen et superieur de Possagno (Italie) . Revue de Micropaleontologie Vol. 13 p. 131-145
Toumarkine,M. (1978): Planktonic Foraminiferal Biostratigraphy of the Paleogene of Sites 360 to 364 and the Neogene of Sites 362A, 363, and 364 Leg 40. In: Initial Results of the Deep Sea Drilling Project Vol. 40
Toumarkine,M. and Luterbacher,H.P. (1985): Paleocene and Eocene Planktic Foraminifera. In: Plankton Stratigraphy p. 87-154
Snyder,S.W. and Waters,V.J. (1985): Cenozoic planktonic foraminiferal biostratigraphy of the Goban Spur region. In: Deep Sea Drilling Project Vol. 80
Coccioni,R.; Monaco,P..; Monechi,S..; Nocchi,M. and Parisi,G.. (1988): Biostratigraphy of the Eocene-Oligocene boundary at Massignano, (Ancona, Italy). In: The Eocene-Oligocene boundary in the Umbria-Marche Basin (Italy): International Subcommission on Paleogene Stratigraphy, (Industrie Grafiche F.lli Anniballi, Ancona) Eds: Premoli Silva, I.Coccioni, R.Montanari, A.. p. 59-80
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
Berggren,W.A.; Kent,D.V.; Swisher,C.C. and Aubry,M.P. (1995): A revised Cenozoic Geochronology and Chronostratigraphy. In: Geochronology Time Scales and Global Stratigraphic Correlation, SEPM Special Publication Vol. 54
Pearson,P.N. and Chaisson,W.P. (1997): Late Paleocene to middle Miocene planktonic foraminifer biostratigraphy of the Ceara Rise. Vol. 154 Eds: Leckie, R.M.Sigurdsson, H.Acton, G.D.Draper, G.
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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