The southern cassowary (Casuarius casuarius), also known as double-wattled cassowary, Australian cassowary or two-wattled cassowary, is a large flightless black bird. It is one of the three living species of cassowary, alongside the dwarf cassowary and the northern cassowary. It is a ratite and therefore related to the emu, ostriches, rheas and kiwis. Taxonomy Presently, most authorities consider the southern cassowary monotypic, but several subspecies have been described. It has proven very difficult to confirm the validity of these due to individual variations, age-related variations, the relatively few available specimens (and the bright skin of the head and neck – the basis upon which several subspecies have been described – fades in specimens), and that locals are known to have traded live cassowaries for hundreds, if not thousands of years, some of which are likely to have escaped/been deliberately introduced to regions away from their origin. Cassowaries are closely related to the kiwis, both families diverging from a common ancestor approximately 40 million years ago. The binomial name Casuarius casuarius is derived from its Malay name kesuari. The southern cassowary was first described by Carl Linnaeus, in his 18th-century work Systema Naturae, as Struthio casuarius, from a specimen from Seram, in 1758. It is now the type species of the genus Casuarius. The southern cassowary has been described under a large number of scientific names, all of which are now considered taxonomic synonyms for the species. Description The southern cassowary has stiff, bristly black plumage, a blue face and a long neck, red on the cape and two red wattles measuring around in length hanging down around its throat. A horn-like brown casque, measuring high, sits atop the head. The bill can range from . The three-toed feet are thick and powerful, equipped with a lethal dagger-like claw up to on the inner toe. The plumage is sexually monomorphic, but the female is dominant and larger with a longer casque, larger bill and brighter-coloured bare parts. The juveniles have brown longitudinal striped plumage. It is perhaps the largest member of the cassowary family and is tied as the third heaviest bird on earth (after the Somali ostrich and the common ostrich), at a maximum size estimated at and tall. Normally, this species ranges from in length. The height is normally ; females average , while males average . The northern cassowary is about the same size on average and is