How many known living species of hyenas are there?

There are four known living species of hyenas: the spotted hyena (Crocuta crocuta), the brown hyena (Hyaena brunnea), the striped hyena (Hyaena hyaena), and the aardwolf (Proteles cristata). These species are distinct in terms of their appearance, habitat, behavior, and geographic distribution. While all four species belong to the Hyaenidae family and share certain characteristics, such as being carnivorous mammals, the anatomical and physiological differences between them justify their classification into separate species.