Globorotalia kugleri Bolli 1957 from: Bolli, H.M. (1957): Planktonic foraminifera from the Oligocene-Miocene Cipero and Lengua formations of Trinidad, B.W.I.. In: Studies in Foraminifery, Bulletin of the U.S. National Museum Vol. 215 Eds: Loeblich, A.R.Tappan, H.Beckmann, J.P.Bolli, H.M.Gallitelli, E.M.Troelsen, J.C. p. 97-123 . |
Notice: This catalogue page may contain unedited data.
|
Species Globorotalia kugleri Bolli 1957 |
|
|
Alternative name: |
|
Diagnosis / Definition: |
Bolli (1957):
Shape of test very low trochospiral; equatorial periphery slightly lobate; axial periphery rounded or with a tendency to become subangular. Wall calcareous, perforate, surface finely pitted. Chambers ovate; 18-20, arranged in 2 1/2 -3 whorls; the 6-8 chambers of the last whorl increase slowly in size. Sutures on spiral side: curved, depressed; on umbilical side radial, depressed. Umbilicus fairly narrow. Aperture a distinct arch, a lip may be present; interiomarginal, umbilical extraumbilical. Coiling random. Largest diameter of holotype 0.3 mm. |
Discussion / Comments: |
Bolli & Saunders (1985):
Globorotalia (Turborotalia) mendacis Blow, 1969, p. 390, pl. 30, figs. 5-6. Typical G. kugleri specimens are comparatively small in size (around 0.3 ram) with 7-8 chambers forming the last whorl, equatorial periphery almost circular, spiral intercameral sutures variable, distinctly curved to straight but swept back as in Figs. 26.1 a, 2, 4, or near radial as in Fig. 26.3a. Depending on the degree of curvature of the intercameral sutures, individual chambers may he of subglobular to distinctly elongate curved shape. For specimens with more radial sutures and more globular chambers Blow (1969) proposed the separate species G. pseudokugleri, citing G. cf. kugleri of Bolli (1957, pl. 28, figs. 7a c, here shown on Fig. 26.3) as holotype. As an intermediate between kugleri forms with distinctly curved sutures and G. pseudokugleri the same author erected a G. mendacis. Apart from extreme forms these three taxa, which virtually have the same range, are difficult to distinguish. As the subdivision appears to have no stratigraphic significance, we agree with Stainforth et al. (1975) that a subdivision of the G. kugleri plexus into these three taxa is not necessary. G. kugleri has found wide application as an index form in the uppermost Oligocene and lowermost Miocene (range: Globorotalia kugleri to Globigerinoides primordius Zone). Certain affinities to Globorotalia fohsi peripheroronda and G. mayeri may readily lead to misidentification of G. kugleri, resulting in incorrect stratigraphic interpretations. It is essential therefore that the taxon is used in a very restricted sense. Here, the number of chambers in the last whorl (7 8) is of prime importance in separating the species from G. fohsi peripheroronda and G. mayeri which both display 5-6 chambers. Other distinguishing characters of G. kugleri are its small size and its more circular equatorial circumference.
Bolli (1957):
Globorotalia kugleri, new species, is distinguished from G. fohsi barisanensis Le Roy by having more chambers in the last whorl. G. kugleri became extinct shortly after the first occurrence of G. fohsi barisanensis. |
Systematics: |
1 Superregnum Eukaryota
Regnum Protoctista
Phylum Ciliophora
Subphylum Postciliodesmatophora
Ordo Globigerinida
Superfamilia Globorotaliaceae
Superfamilia Nonionacea
Familia Globorotaliidae
Genus Globorotalia
Species Globorotalia kugleri
32 Ordo Foraminiferida
Familia Globorotaliidae
Genus Globorotalia
Species Globorotalia kugleri
|
Synonym list: |
Bolli & Saunders (1985):
Bolli (1957):
Vincent & Toumarkine (1990):
|
Was used in synonym list of: |
|
Stratigraphy - absolute ages: |
FAD: 23.8 ± 0 [Ma], Berggren et al. (1995)
LAD: 21.5 ± 0 [Ma], Berggren et al. (1995)
|
References: |
Bolli,H.M. (1957): Planktonic foraminifera from the Oligocene-Miocene Cipero and Lengua formations of Trinidad, B.W.I.. In: Studies in Foraminifery, Bulletin of the U.S. National Museum Vol. 215 Eds: Loeblich, A.R.Tappan, H.Beckmann, J.P.Bolli, H.M.Gallitelli, E.M.Troelsen, J.C. p. 97-123
Blow,W.H. (1969): Late middle Eocene to Recent planktonic foraminiferal biostratigraphy. In: Proceedings of the First International Conference on Planktonic Microfossils, Geneva 1967 Vol. 1 Eds: Bronnimann, P.Renz, H.H. p. 199-422
Bolli,H.M. and Saunders,J.B. (1985): Oligocene to Holocene low latitude planktic foraminifers. In: Plankton Stratigraphy Eds: Bolli, H.M.Saunders, J.B. p. 155-262
Vincent,E. and Toumarkine,M. (1990): Neogene planktonic foraminifers from the Western Tropical Indian Ocean, Leg 115. In: Proceedings of the Ocean Drilling Program, Scientific Results Vol. 115 Eds: Duncan, R.A..Backman, J.Peterson, L.C. p. 795-836
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
|
This work is licensed under a Creative Commons Attribution 2.5 License.
|
|