pforams@mikrotax - Turborotalia cunialensis

Turborotalia cunialensis

Classification: pf_cenozoic -> Globanomalinidae -> Turborotalia -> Turborotalia cunialensis
Sister taxa: T. cunialensis, T. cocoaensis, T. cerroazulensis, T. pomeroli, T. frontosa, T. ampliapertura, T. increbescens, T. altispiroides, T. possagnoensis, T. sp.,

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Taxonomy

Citation: Turborotalia cunialensis (Toumarkine & Bolli 1970)

Rank: Species

Basionym: Globorotalia cerroazulensis subsp. cunialensis Toumarkine & Bolli, 1970

Synonyms:

Globorotalia cerroazulensis cunialensis Toumarkine and Bolli, 1970:144-145, pl. 1: fig. 37-39 [upper Eocene, Possagno area, Italy].—Toumarkine, 1978:712, pl. 7: figs. 1-12 [upper Eocene Globigerinatheka semiinvoluta Zone, DSDP Site 363, Walvis Ridge, South Atlantic Ocean].— Snyder and Waters, 1985:460, pl. 3: fig. 1-2 [upper Eocene Zone P17, DSDP Hole 549A, Goban Spur, North Atlantic Ocean].
Turborotalia cerroazulensis cunialensis (Toumarkine and Bolli).—Toumarkine and Luterbacher, 1985:138, figs. 34.1 (re-illustration of holotype), 36.1-6 (re-illustrations from the literature).
Turborotalia cunialensis (Toumarkine and Bolli). —Coccioni and others, 1988, pl. 1:figs. 7-9 [upper Eocene Zone P16, Massignano, Italy].

Taxonomic 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 imperforate 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. [Pearson et al. 2006]

Catalog entries: Globorotalia cerroazulensis cunialensis

Type images:

holotype: Globorotalia cerroazulensis cunialensis
x: Globorotalia cerroazulensis cunialensis
x: Globorotalia cerroazulensis cunialensis
x: Globorotalia cerroazulensis cunialensis
x: Globorotalia cerroazulensis cunialensis

Distinguishing features: Like T. cocoaensis but more acute periphery to final chamber, and biconvex morphology.

NB These concise distinguishing features statements are used in the tables of daughter-taxa to act as quick summaries of the differences between e.g. species of one genus.
They are being edited as the site is developed and comments on them are especially welcome.

Description

Diagnostic characters: Turborotalia cunialensis is distinguished 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. [Pearson et al. 2006]

Wall type: Smooth, normal perforate; tendency to defoliate (e.g., Snyder and Waters, 1985). [Pearson et al. 2006]

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 embracing, wedge-shaped in ventral aspect and increasing moderately in size; final chamber distinctly acute (<40o) 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; umbilicus very narrow; ventral sutures moderately curved, depressed. Strong tendency for sinistral coiling. [Pearson et al. 2006]

Size: Holotype length 0.45 mm. [Pearson et al. 2006]

Character matrix

test outline:	Subcircular	chamber arrangement:	Trochospiral	edge view:	Equally biconvex	aperture:	Umbilical-extraumbilical
sp chamber shape:	Crescentic	coiling axis:	Low	periphery:	Imperforate band	aperture border:	N/A
umb chbr shape:	Subtriangular	umbilicus:	Narrow	periph margin shape:	Subangular	accessory apertures:	None
spiral sutures:	Raised	umb depth:	Shallow	wall texture:	Smooth	shell porosity:	Finely Perforate: 1-2.5µm
umbilical or test sutures:	Moderately depressed	final-whorl chambers:	4.0-5.0	N.B. These characters are used for advanced search. N/A - not applicable

Biogeography and Palaeobiology

Geographic distribution: Cosmopolitan, possibly more restricted to tropical latitudes than T. cerroazulensis. [Pearson et al. 2006]
Aze et al. 2011 summary: Cosmopolitan; based on Pearson et al. (2006)

Isotope paleobiology: No data available [Pearson et al. 2006]
Aze et al. 2011 ecogroup 2 - Open ocean mixed-layer tropical/subtropical, without symbionts. Based on δ¹³C lighter than species with symbionts; also with relatively light δ¹⁸O. Sources cited by Aze et al. 2011 (appendix S3): this study

Phylogenetic relations: Evolved from Turborotalia cocoaensis in the upper Eocene (Toumarkine and Bolli, 1970). [Pearson et al. 2006]

Most likely ancestor: Turborotalia cocoaensis - at confidence level 4 (out of 5). Data source: Pearson et al. (2006), fig 15.1.

Biostratigraphic distribution

Geological Range:
Notes: 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. [Pearson et al. 2006]
Last occurrence (top): in upper part of E16 zone (80% up, 34.1Ma, in Priabonian stage). Data source: Pearson et al. (2006), fig. 15.1
First occurrence (base): in lower part of E16 zone (30% up, 34.4Ma, in Priabonian stage). Data source: Pearson et al. (2006), fig. 15.1

Plot of occurrence data:

Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
Note to users in China - the diagram may not plot unless you use a VPN since I use google services on the website. If this is a problem please contact me 谢谢.
Taxon plotted: Turborotalia cunialensis, synonyms included - Turborotalia cerroazulensis cunialensis; Turborotalia cunialensis;
space-time plot :: Samples map :: Parent: Turborotalia

Primary source for this page: Pearson et al. 2006 - Eocene Atlas, chap. 15, p. 450

References:

Bolli, H. M. (1970). The foraminifera of sites 23-31, leg 4. Initial Reports of the Deep Sea Drilling Project. 4: 577-643. gs

Coccioni, R., Monaco, P., Monechi, S., Nocchi, M. & Parisi, G. (1988). Biostratigraphy of the Eocene-Oligocene boundary at Massignano, (Ancona, Italy). In, Premoli Silva, I. , Coccioni, R. & Montanari, A. (eds) The Eocene-Oligocene Boundary in the Marche-Umbria Basin (Italy). International Subcommission on Paleogene Stratigraphy, Ancona 59-80. gs

Pearson, P. N. & Wade, B. S. (2015). Systematic taxonomy of exceptionally well-preserved planktonic foraminifera from the Eocene/Oligocene boundary of Tanzania. Cushman Foundation for Foraminiferal Research, Special Publication. 45: 1-85. gs

Pearson, P. N., Premec-Fucek, V. & Premoli Silva, I. (2006b). Taxonomy, biostratigraphy, and phylogeny of Eocene Turborotalia. 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 15): 433-460. gs

Snyder, S. W. & Waters, V. J. (1985). Cenozoic planktonic foraminiferal biostratigraphy of the Goban Spur Region, Deep Sea Drilling Project Leg 80. Initial Reports of the Deep Sea Drilling Project. 80: 439-472. gs

Toumarkine, M. & Bolli, H. M. (1970). Evolution de Globorotalia cerroazulensis (Cole) dans l'Eocene moyen et superieur de Possagno (Italie). Revue de Micropaléontologie. 13(3): 131-145. 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

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,. Initial Reports of the Deep Sea Drilling Project. 40: 679-721. gs