A different asexual reproduction in Simplorbites papyraceus (BOUBEE) samples of Karaçam Highland (Niksar-Türkiye): A1x Individuals

Abstract

A different asexual reproduction phase within Simplorbites papyraceus (BOUBEE), individuals observed in the Uppermost Maastrichtian "Sirakayalar Detritic Limestone Member" (SEYMEN, 1975), which is exposed around the Karaçam Highland east of Niksar (Tokat-Türkiye) were determined and these individuals were named as "A1x individuals." In normal individuals of Simplorbites papyraceus (BOUBEE), the embryo have numerous chamber and are rounded and present a thick wall. On the other hand, in A1x individuals, embryo contain lateral chamber and stolons and are surrounded by thicker embryonic walls (50 to 250 ?m). Lateral chamber in embryonic walls are well developed and are lined up in 2-5 rows. A1x individuals are larger than normal individuals. In this study, 65 % of Simplorbites papyraceus (BOUBEE), specimens sampled in the uppermost part of the Maastrichtian, represents A1x individuals. However, only 8 % represents normal individuals. Abnormal ecological conditions of transition during Cretaceous / Tertiary are thought to be the result of A1x individuals development. This conditions may be supported by an observed intensity of phase reproduction in first whorls of reshaped and budded teratological individuals of Orbitoides, Hellenocyclina and Siderolites. Changed ecological conditions caused the embryonic wall thickening of Simplorbites papyraceus (BOUBEE). Thus, the partitioning of the species embryo was delayed. This delay may have caused the formation of lateral chamber by the lateral development of the embryo within the wall.