The genus Lepidorbitoides: Evolution and stratigraphic significance in some Anatolian basins (Turkey)

• Published in: Revue de Micropaléontologie
• Main Authors: Özcan E., Özkan-Altiner S.
• Other Authors: 0-Belirlenecek
• Format: Article in Journal/Newspaper
• Language: English
• Published: Maison de Geologie 1999
• Subjects: Campanian-Maastrichtian; Evolution; Lepidorbitoides; Nepionic arrangement; Turkey; Planktonic foraminifera
• Online Access: https://hdl.handle.net/11480/1422; https://doi.org/10.1016/S0035-1598(99)90109-5

Evolution of Lepidorbitoides in some flysch basins of Anatolia has been investigated considering the early ontogenesis in horizontal sections. Different developmental states of L. permbergeri, L. campaniensis, L. bisambergensis, L. minor and L. socialis have been described and illustrated with their morphometric features based on the earliest chamber arrangement. A correlation scheme of phylogenetic developmental states of Lepidorbitoides to the planktonic foraminiferal zones is also proposed. Populations with highly asymmetric quadriserial nepionts identified stratigraphically below the symmetric ones in Early Maastrichtian are thought to deserve a new status and attributed to L. bisambergensis asymmetrica n. spp. Orbitoides in common association with Lepidorbitoides has also been studied for the evolution of embryo-related parameters such as embryo size (Li + Ii), number of epi-embryonic chambers (E) and other embryonal features to correlate the phylogenetic developmental state of both genera. The authors would like to acknowledge the Scientific and Technical Council of Turkey for funding the project (T1JBiTAK, YDAB~AG-69) "Microfacies variations around Cretaceous-Tertiary boundary: An integrated zonation of calcareous nannofossil, planktonic foraminifera and benthic foraminifera" related to the subject of this paper.