The aim of the study was to investigate the shape of the foramen magnum and condylus occipitalis of mammalian species belonging to different feeding groups. For this, two-dimensional geometric morphometric method analyses were applied. The data from the skulls of the 12 species were used. In principal component analysis, the first three principal components accounted for 70.353%of the total shape variation. According to the first principal component, the dorsal edge of the condylus occipitalis and foramen magnum contributed the most to shape variation. Most of the individuals were correctly separated according to the feeding groups. The most accurate grouping features were herbivorous and omnivorous. The mean shape of the foramen magnum and condylus occipitalis differed according to the feeding groups. As a result, our hypothesis was strengthened that the general shape of the analyzed region is influenced by the feeding factor.