Igorina broedermanni Cushman & Bermudez 1949 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.
|
Species Igorina broedermanni Cushman & Bermudez 1949 |
|
|
|
| Diagnosis / Definition: |
Pearson et al. (2006):
DESCRIPTION.
Type of wall: Muricate, normal perforate,
nonspinose.
Test morphology: Test low trochospiral,
subcircular, weakly lobulate outline, planoconvex to
weakly biconvex, blunt-tipped muricae covering both sides of test; in umbilical view involute, 6-7 essentially
equidimensional, broadly triangular-shaped chambers,
sutures depressed, radial, umbilicus narrow, deep,
bordered by coalescing circumumbilical muricate,
triangular chamber tips, aperture a low slit extending
towards peripheral margin; in spiral view about 1 1 - 12
chambers in 2 1/2 whorls gradually increasing in size in
an evolute coil, broadly subquadrate to subrectangular
in shape, intercameral sutures curved and retorse at
junction with peripheral margin; in edge view,
planoconvex to weakly biconvex, rounded tu subangular,
noncarinate.
Size: dimensions of holotype: length: 0.33 mm;
breadth: 0.28 mm; thickness: 0.18 mm (Cushman and
Bermudez, 1040, p. 40). |
| Discussion / Comments: |
Pearson et al. (2006):
DISTINGUISHING FEATURES. -
Characterized by
bluntly muricatc, weakly biconvcx to planoconvex test,
rounded (noncarinate) periphery and narrow umbilicus;
distinctly curved to retorse sutures on spiral side.
Distinguished from I. lodoensis by its less lobulate
periphery and flatter spiral side, and from I. anapetes
by having fewer chambers in the final whorl and a
narrower umbilicus.
PHYLOGENETIC RELATIONSHAPES. - Descended
from Igorina lodoensis and evolved into I anapetes by
increase in number of chambers.
DISCUSSI0N -
This(predominantly) Eocene taxon
figures prominently in early and early middle Eocene (sub)tropical assemblages. It may be considered the
central form of the "Morozovella broederrmanni group"
(Premoli Silva and Boersma, 1088, p 344) which is closely related to, and descended from, the group of
"biconvcu morozovelloids"( Premoli Silva and Boersma, 1988, 344), characterized by Igorina convexa/tadjikistanensis and related forms (see also Premoli Silva and Boersma, 1989; Blow, 1979, p. 934). Pearson (1093, p. 20; text-fig. 14) included broedermanni in the group of "biconvex morozovelloids" ("Acarinina pusilla group") recognizing that it (and related forms) was probably not referable to either Morozovella or Acarinina. Berggren and Norris (1997) included these forms in Igorina (see also Olsson and others, 1999 for further discussions).
Blow (1970) distinguished Globorotalia broedermanni lodoensis Mallory (from the lower Eocene part of the Lodo Fm. of California) as a lower Eocene (Zone P5-P8b) ancestor of broedermanni s. str., which was said to range from Zone P8a to P11 (~ Zone E5-9 of this paper). Distinction between the two was based upon subtle (but distinct) differences such as: ussually lower number of chambers in last whorl, relatively more tightly coiled test resulting in narrower umbilicus, more smoothly recurved dorsal intercameral sutures and more lobulate periphery (lodoensis) vs. proximally more radial but marginally/distally sharply retorse sutures, more evolute coiling resulting in somewhat larger umbilicus particularly in younger forms, slightly more inflated chambers ventrally and dorsally in some instances, somewhat more equally biconvex and greater appression of chambers in the last convolution of the test, and slightly more tightly coiled test (broedermanni; see futher discussion under lodoensis below).
We have observed that Igorina broedermanni evolved from I. lodoensis the middle part of (former)
Zone P5, just below the Paleocene Eocene Thermal
Maximum (PETM) in the Dababiya, Qreiya and Qwaina
sections of Egypt and in the Bass River borchole of the
New Jersey Coastal Plain. It occurs relatively commonly
in the middle to upper part of the Esna Shale Fm. (Zones
P6 and P7 - Zones E3-5) at Dababiya and other sections
in Egypt. In the PETM interval, the chambers on the
umbilical side of individuals of broedermanni are
relatively weakly inflated; it is only above the Carbon Isotope Excursion PETM (i.e. above Zone E1) that the
chambers exhibit an inflational tendency, the test
becomes distinctly umbilico-convex and the taxon broedermanni assumes its typical appearance.
Includcd by us in broedermanni are the taxa Globorotalia mattseensis and Globorotalia warsteinensis of Gohrbandt (1967) and Acarinina planodorsalis of Fleisher (1974). Together these taxa illustrate a gradual morphologic trend in middle Eocene Igorina broedermanni towards increasing number of chambers in the final whorl and flattening of the dorsal side that culminates in the evolution of Igorina anapetes.
STRATIGRAPHIC RANGE.-
Just below E1 to top of Zone E9.
GEOGRAPHIC DISTRIBUTION.-
Widespread in Caribbean (Cuba, Trinidad), Atlantic and Indo-Pacific realms as well as in Tethys (Syria, Egypt, Tunisia, Senegal, Yugoslavia, Italy), Caucasus regions. Krasheninnikov (1974, p. 121) noted that broedermanni occurs in the Atlantic (Sites 6, 19, 20, 21, 22), Pacific (Sites 47, 162, 200) and Indian (Sites 219, 223) Oceans. It has not been reliably reported from high southern (austral) latitudes according to our information.
STABLE ISOTOPE PALEOBIOLOGY.-
Recording by Pearson and others (1993)(as 'Morozovella broedermanni') and Pearson and others (2001) as a
surface mixed-layer species with very positive ò13C
indicating a mixed layer symbiotic habitat. |
| Systematics: |
35
Ordo Foraminiferida
Superfamilia Globigerinaceae
Familia Truncorotaloididae
Genus Igorina
Species Igorina broedermanni
|
| Synonym list: |
Pearson et al. (2006):
1957 Globorotalia broedermanni Cushman & Bermudez. - Bolli : p.80 pl. 19; fig. 13-15 [lower
Eocene Globorotalia formosa formosa Zone, upper Lizard
Springs Fm., Trinidad]
1957 Globorotalia broedermanni Cushman & Bermudez. - Bolli : p.167 pl. 37; fig. 13a-c [lower Eocene
Globorotalia palmerae Zone, Navet Fm.,
Trinidad]
1961 Pseudogloborotalia broedermanni Cushman & Bermudez. - Bermudez : p.1340 pl. 16; fig. 7 [stereoscopic pair; topotype from lower Eocene Capdevila
Fm., Havana Province, Cuba]
1964 Globorotalia broedermanni Cushman & Bermudez. - Said & Sabry : p.382 pl. 1; fig. 4a-c [lower Eocene, upper Esna Shale Fm., Gebel
Oweina, Egypt]
1967 Globorotalia mattseensis Gohrbandt. - Gohrbrandt : p.322 pl. l, fig.
25-27 (paratype), 28-30 (holotype) [middle Eocene Zone
P10, Helvetikum, Mattsee, Salzburg, Austria]
1967 Globorotalia warsteinensis Gohrbandt. - Gohrbrandt : p.324 pl. 1; fig. 18-24 [lower to middle Eocene, Helvetikum, Mattsee,
Salzburg, Austria]
1974 Acarinina broedermanni Cushman & Bermudez. - Krasheninnikov : p.121 pl. 7; fig. 5a-c [lower Eocene Globorotalia aragonensis Zone, Biral
village, southern Armenia]
1974 Acarinina planodorsalis Fleisher. - Fleisher : p.1013 pl. 2; fig. 6-8 (holotype), 9 (paratype) [Zone P1 1, DSDP Site
21 9, Chagos - Laccadive Ridge, eastern Arabian Sea]
p 1975 Globorotalia broedermanni Cushman & Bermudez. - Stainforth et al. : p. 173-174 text-fig. 39.4-
6 , (reillustration of Bolli, 1957b, pl. 37: figs. 13a-c) (not text-figs. 39.2a-3c); [lower
Eocene]
1979 Globorotalia (Acarinina) broedermanni broedermanni Cushman & Bermudez. - Blow : p.911 pl. 130, fig. 7-9;
pl. 135, fig. 4 [lower Eocene Zone PSb, , DSDP
Hole 47.2, Shatsky Rise, northwest Pacific Ocean];
pl. 142, fig. 1-3 [lower Eocene Zone P8b, DSDP Hole 20C, South Atlantic Ocean];
pl. 148, fig. 1-3;
pl. 153: figs. 7, 8 [lower Eocene Zone P9, Kane 9-C piston core, South Atlantic Ocean];
pl. 179, fig. 3-5 [lower Eocene Zone P 11, DSDP Hole 2 IA, South Atlantic Ocean]
1983 Globorotalia broedermanni Cushman & Bermudez. - Pujol : p.645 pl. 4, fig. 10, 11
[middle Eocene Zone P1 0, DSDP Hole 5 16F, Rio Grande Rise, South Atlantic Ocean];
pl. 5, fig. 5 [middle Eocene
Zone P 11 -1 3, DSDP Hole 5 16F, Rio Grande Rise, South Atlantic Ocean];
pl.6, fig. 5 [middle Eocene Zone P11-
13, DSDP Hole 516F, Rio Grande Rise, South Atlantic Ocean]
1985 Globorotalia broedermanni Cushman & Bermudez. - Toumarkine & Luterbacher : p.130 text-fig.
29. 14a-c (holotype refigured), 15-1 6 [middle Eocene, Bou Aradia, Tunisia];
fig. 20a-c [from Bolli, 1957b, pl.
37: figs. 13a-c]
1985 Acarinina broedermanni Cushman & Bermudez. - Snyder & Waters : p.446 pl. 6; fig. 1-3 [middle Eocene Zone
P10/1 1, DSDP Site 549, Goban Spur, northeast Atlantic
Ocean]
1993 "Morozovella" broedermanni Cushman & Bermudez. - Pearson et al. : p.125 pl. 1; fig. 21 [middle Eocene
Zone P l l , DSDP Site 523, South Atlantic Ocean]
1995 Igorina broedermanni Cushman & Bermudez. - Lu & Keller : p.102 pl. 4; fig. 16 [lower Eocene Zone P9,
DSDP Site 577, Shatsky Rise, northwest Pacific
Ocean]
2000 Igorina broedermanni Cushman & Bermudez. - Warraich et al. : p.293 fig. 18.18-20 [lower Eocene Zone P7, Dungan Fm., Rakhi Nala section,
Sulaiman Range, Pakistan]
2001 Igorina broedermanni Cushman & Bermudez. - Warraich & Ogasawara : p.17 fig. 4.1-3 [lower Eocene Zone P7, Dungan Fm.,
Rakhi Nala section, Sulaiman Range, Pakistan]
2004 Igorina broedermanni Cushman & Bermudez. - Pearson et al. : p.37 pl. 2; fig. 2 [middle Eocene, Zone
P11, Tanzania Drilling Project Site 2, Kilwa Masoko,
Tanzania]
2006 Igorina broedermanni Cushman & Bermudez. - Pearson et al. : p.383 pl. 12.2; fig. 1-12 (Plate 12.2, Figs. 1-3: new SEMs of holotype of
Globorotalia (Truncorotalia) broedermanni Cushman and
Bermudez)
|
| Specimen: |
Smithsonian Museum of Natural History, Washington, D.C., Inventory number: CC 47407
|
| References: |
Cushman,J.A. and Bermudez,P.J. (1949):
Some Cuban species of Globorotalia . Contributions from the Cushman Foundation for Foraminiferal Research Vol. 25 p. 26-44
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
Bolli,H.M. (1957):
Planktonic Foraminifera from the Eocene Navet and San Fernando formations of Trinidad, B.W.I. . Bull. U.S. natl. Mus. Vol. 215 p. 155-172
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
Said,R. and Sabry,H. (1964):
Planktonic Foraminifera from the Type Locality of the Esna Shale in Egypt . Micropaleontology Vol. 10 p. 375-395
Gohrbrandt,K.H.A. (1967):
Some new foraminiferal species from the Austrian Eocene . Micropaleontolgy Vol. 13 p. 319-326
Postuma,J.A. (1971):
Manual of Planktonic Foraminifera. p. 422 pp
Krasheninnikov,V.A. (1974):
Nekotoryie vidy planktonnykh foraminifer iz eotsovykh oligotsenovykh otlozhenii yuzhnoi armenii . Voprosy Mikropaleontologii Vol. 17 p. 95-135
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
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
Cifelli,R. and Belford,D.J. (1977):
The Types of several Species of Tertiary Planktonic Foraminifera in the Collections of the U.S. National Museum of Natural History . Journal of Foraminiferal Research Vol. 7 p. 100-105
Blow,W.H. (1979):
The Cainozoic Globigerinida. 3 Vols p. 1413 pp
Pujol,C. (1983):
Cenozoic Planktonic Foraminiferal Biostratigraphy of the Southwestern Atlantic (Rio Grande Rise): Deep Sea Drilling Project Leg 72.
In: Initial Reports of the Deep Sea Drilling Project Vol. 72 Eds: Barker, P.F.Johnson, D.A. p. 623-673
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
Pearson,P.N.; Shackleton,N.J. and Hall,M.A. (1993):
The Stable Isotope Paleoecology of Middle Eocene Planktonic Foraminifera and Multi-species integrated Isotope Stratigraphy . Journal of Foraminiferal Research Vol. 23 p. 123-140
Lu,G. and Keller,G. (1995):
Planktic Foraminiferal Faunal Turnovers in the Subtropical Pacific during the Late Paleocene to Early Eocene . Journal of Foraminiferal Research Vol. 25 p. 97-116
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.; Nicholas,C.J..; Singano,J.M..; Bown,P.R..; Coxali,H.K..; van Dongen,B.E..; Huber,B.T.; Karega,A..; Lees,J.A..; Misaky,E..; Pancost,R.D..; Pearson,M.. and Roberts,A.P.. (2004):
Paleogene and Cretaceous sediment cores from the Kilwa and Lindi areas of coastal Tanzania: Tanzania Drilling Project Sites 1-5 . Journal of African Earth Sciences Vol. 39 p. 25-62
Pearson,P.N.; Olsson,R.K.; Hemleben,C.; Huber,B.T. and Berggren,W.A. (2006):
Atlas of Eocene Planktonic Foraminifera. p. 1-513
|
This work is licensed under a Creative Commons Attribution 2.5 License.
|
|
Taxon Concept provided by