Cryptoprocta ferox belongs to the Mammalian order Carnivora, meaning ‘flesh-eating’.Cryptoprocta means ‘hidden in the hinder parts’. This refers to an anal pouch containing a gland that secretes foul-smelling fluid (Gotch, 1979). This pouch also conceals the anus (Kohncke, 1986).The name ferox refers to its exaggerated reputation of being fierce (Gotch, 1979).The vernacular name ‘fossa’ or ‘foussa’ is a Malagasy name and is often confused with the generic name of Fossa fossana, the Malagasy civet. The 2 are not closely related (Nowak, 2005). The vernacular name may also be spelt as ‘fosa’ (Kohncke, 1986).The taxonomy of the Malagasy carnivores is problematic and the classification for Cryptoprocta ferox is still in debate (Wilson, 2005).

Morphology
Cryptoprocta ferox has several features similar to the Felidae. The dentition is characteristic of advanced carnivores - the carnassials are enlarged and there is one reduced upper molar. The skull has a shortened braincase and enlarged orbits (Ewer 1973).

Scent glands
The anal scent glands produce a pungent odour when the animal is aggravated (Nowak, 2005).Cryptoprocta ferox also has chest glands that fully develop upon sexual maturity. They are larger in males and secretions are more active during the breeding season (Ewer, 1973).See video footage of the fossa scent marking on the Arkive website.

Claws
Cryptoprocta ferox is plantigrade and the retractile claws are short, sharp and curved (Nowak, 2005).See video footage of the fossa grooming on the Arkive website.

Pelage
The fur is short, dense, soft and usually red-brown but occasionally black.Malagasy people originally thought this variation represented different species but it is more widely accepted that the colouration is melanistic.The vibrissae (whiskers) are especially pronounced and are as long as the head (Kohncke, 1986), (Nowak, 2005).