The Ampullinid Gastropod Globularia (Swainson 1840) from the Late Thanetian-Early Ilerdian Kırkkavak Formation (Polatlı-Ankara) of the Tethyan Realm

Authors: YAVUZ OKAN, İZZET HOŞGÖR

Abstract: Ampullinid gastropods are useful in correlating the Palaeogene marine strata of Central Anatolia. Ampullinid gastropods are found in the Late Paleocene-Early Eocene Kırkkavak Formation in the Macunköy area (Polatlı, west of Ankara). In the Haymana-Polatlı Basin, a variety of Globularia (Swainson 1840) species is described from the upper part of the Kırkkavak Formation, including G. sireli n.sp. The other taxa are G. vapincana (d´Orbigny 1850), G. grossa (Deshayes 1864) and G. crassatina (Lamarck 1804). The Kırkkavak fauna is known in western and central Europe, and central Asia. Some of the ampullinid gastropods and associated cerithid and neritid gastropods as well as bivalves are conspecific with forms from the Palaeogene of Europe and central Asia. The palaeobiogeographical affinity of the ampullinid Globularia fauna is typically Tethyan, with many taxa that are known particularly from western-central Tethys. The inferred palaeo-environment, as implied by the ampullinids, is a shallow shelf. There is a marked stratigraphic lag between the first appearance of Globularia species in central Anatolia in the Late Paleocene-Early Eocene, and the later documented appearance of the genus in the Early Eocene-Early Oligocene in Europe. This suggests that central Anatolia was located on the westward migration route of the Early Eocene ampullinid faunas.

Keywords: Globularia, Late Paleocene-Early Eocene, Kırkkavak Formation, Turkey

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