¹Istanbul University-Cerrahpasa, Faculty of Veterinary, Department of Anatomy, TR-34500 İstanbul - TÜRKİYE
²İstanbul University-Cerrahpasa, Faculty of Veterinary, Department of Surgery, TR-34500 İstanbul - TÜRKİYE
³Istanbul University-Cerrahpasa, Faculty of Veterinary, Department of Animal Husbandry, TR-34500 İstanbul - TÜRKİYE DOI : 10.9775/kvfd.2023.30549 The first cervical vertebra, the atlas, connects the skull to the body and plays a crucial role in supporting the skull and holds a distinct position within the atlanto-axial complex. In this study was aimed to examine the shape variation of the atlas in cats and to reveal shape changes related to variation in size via geometric morphometry. A total of 61 (31 mix-breed cats, 30 Tekir cats) cats were used. Shape differences were examined both for mix-breed cats and Tekir cats and between sexes. However, it was seen that the shape difference between species (P:0.1644) and between sexes (P:0.4801) was insignificant according to the discriminant function results. The average shape and shape variations of the atlas were obtained for all samples. A total of 52 principal components were obtained. PC1 explained 28.39% of the total variation. Tekir cats showed more shape variation than mix-breed cats for results of PC1 and PC2. Mix-breed cats had a larger ala atlantis than Tekir cats as shape. Incisura alaris were deeper in shape in mix-breed cats. Foramen vertebrale laterale of the male was more medial in shape than female. It was performed a multivariate regression of the procrustes coordinates as shape variables on the log-transformed centroid size values as a size variable to analyze the allometry of atlas for all samples. However, allometry results were statistically insignificant (P:0.3579). In this study, encompassing breed and sex comparisons in cats, will serve as a pioneering effort in future atlas research, offering substantial data concerning cat atlas bones. Keywords : Geometric morphometry, shape variation, taxonomy, veterinary anatomy