 The saddleback carapace probably evolved independently several times in dry habitats, since genetic similarity between populations does not correspond to carapace shape.Saddleback tortoises are, therefore, not necessarily more closely related to each other than to their domed counterparts, as shape is not determined by a similar genetic background, but by a similar ecological one.Sexual dimorphism is most pronounced in saddleback populations in which males have more angled and higher front openings, giving a more extreme saddled appearance.