Turkish Journal of Earth SciencesTimidonella? primitiva n. sp. (Foraminiferida) from the Middle Jurassic of the Eastern Taurides (Southern Turkey): Remarks on Evolutionary Steps of Hauraniids
1 General Directorate Mineral Research and Exploration,
Geological Research Department,
Palaeontology Unit, TR-06520 Ankara, Turkey
2 Marine Micropaleontology Research Laboratory, Middle East Technical University,
Department of Geological Engineering, TR-06531 Ankara, Turkey
Abstract: A new species of complex benthic foraminifera, Timidonella? primitiva n.sp., has been identified from the Aalenian?-Bajocian of the eastern Taurides, Turkey. The new species, belonging to the family Hauraniidae SEPTFONTAINE, occurs in the lowermost beds of the Köroğlutepesi Formation and its test is composed of a planispirally coiled early stage followed by an uncoiled rectilinear portion. The internal structure is characterized by four different zones consisting of a subepidermal reticulate layer, a zone of subepidermal plates, a more internal empty zone in the chambers and a primitive interseptal pillar system in the most internal part of the chambers perforated by multiple apertures. Contrary to previous opinions, which considered that Timidonella had evolved from the deserta group, this study suggests instead that derivation of the Timidonella was from the amiji group of hauraniids. Timidonella? primitiva n.sp. was probably an early step derived from the amiji group and led to the evolution of the more advanced species, Timidonella sarda.
Key Words: Foraminifera, new species, evolution, taxonomy, Bajocian, Taurides, Turkey
Turkish J. Earth Sci., 17, (2008), 73-84.
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