Complex sentence: In reptiles, Chelonians, crocodiles and snakes are unable to regenerate lost parts, but many (not all) kinds of lizards, geckos and Iguanas possess regeneration capacity in a high degree.
Split into simpler sentences: In reptiles, Chelonians, crocodiles and snakes are unable to regenerate lost parts. But many (not all) kinds of lizards, geckos and Iguanas possess regeneration capacity in a high degree.