Bolli & Saunders (1985):
This is the end form of the fohsi lineage. It differs from lobata in having a more compact, circular outline in equatorial view, instead of being more elongate like the earlier fohsi subspecies. The last chambers are generally less elongate compared with lobata with the periphery not lobate or, if it is, only very slightly so and only in the last few chambers. A distinct peripheral keel is present throughout the last whorl which tends to have more chambers (7-8) than does lobata. The spiral side of the test is usually lower, the umbilical side higher.
Srinivasan (1975):
Globorotalia fohsi robusta, which is the end
member of the G. fohsi lineage (Bolli, 1957), is very rare
in the examined area, but intermediate forms linking G.
fohsirobusta to its ancestor, G. fohsilobata, are frequent. |
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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
Srinivasan,M.S. (1975): Middle Miocene Planktonic Foraminifera from the Hut Bay Formation, Little Andaman Island, Bay of Bengal . Micropaleontology Vol. 21(2) p. 133-150
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
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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
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