Biometric analysis and evolution of Nummulites in lutetian-priabonian (middle-upper eocene) depositsaround Yazihan southwest (nw Malatya)

This study aims to conduct an approach to their evolution of biometric analysis on the basis of the Nummulites forms from the Lutetian-Priabonian (Middle-Upper Eocene) sediments that were exposed in the southwest of Yazıhan (northwest Malatya). Lutetian - Priabonian (Middle - Upper Eocene) aged Tohma formation, showing a wide spread in the study area, is represented by Lutetian (Middle Eocene) aged conglomerate-sandstone, sandy limestone, limestone-marl, gravelly sandstone-siltstone-clayey limestone, limestone-marl, limestone and Priabonian (Upper Eocene) aged limestone-marl, limestone lithologies from the bottom to the top. Macrospheric and microspheric Nummulites individuals were yielded from marl and clayey limestone levels of the carbonate sediments. Nummulites incrassatus de la Harpe and Nummulites chavannesi de la Harpe (Priabonian), Nummulites perforatus (de Montfort) (Barthonian), Nummulites aturicus Joly & Leymerie and Nummulites praefabianii Varentsof & Menner (Upper Lutetian), Nummulites beaumonti d'Archiac&Haime (Upper Lutetian),Nummulites migiurtinus Azzaroli (Middle Lutetian) species were described from 61 washing samples taken from the marl and clayey limestone levels from the bottom to the top of the measured cross-sections number I (near Çivril village) and II (near the village of Epreme) from the thesis area. 267 forms of these species were examined and 8 biometric features (shell diameter (A), shell thickness (B), first chamber diameter (C), diameter of the first two tours (inner diameter) (D), the number of total lodges in the first two tours (E), number of tour (T), the relative thickne s (2B / A) and internal diameter / first chamber (D / C)) were measured. From these biometric measurements, a table with the iv breakdown of data for both regions was created. In this table, Average Value Scales were determined based on the upper limit of the calculated mean values for each species. 8 biometric measurement relations of the thesis area Nummulites; diagrams A-B, 2B / A-A, C-D, E-D, C-E, D / C-E, C-2B / A, 2B / A-D, 2B / A-D / C, E-2B / A and A / 2-T were prepared. As a result of overlapping spread of 7 species observed in the diagrams, the thesis Nummulites were collected under two groups as, large-diameter, granular species (Nummulites aturicus Joly & Leymerie, Nummulites perforatus (de Montfort) and granular (Nummulites praefabianii Varentsof & Menner) with white buttons (Nummulites migiurtinus Azzaroli, Nummulites beaumonti d'Archiac & Haime, Nummulites incrassatus de la Harpe, and Nummulites chavannesi de la Harpe In particular, the properties of macrospheric and microspheric forms and their phylogenetic developments reveals four evolutionary line (Nummulites aturicus - perforatus, Nummulites migiurtinus - beaumonti, ?Nummulites variolarius - incrassatus and chavannesi with Nummulites praefabianii - aff. fabianii - fabianii). Key words: Biometric analysis, Evolution, Lutetian-Priabonian, Nummulites, Yazıhan-Malatya.