Emuarius was an early member of the Casuariidae; closely related to both Cassowaries and Emus. The generic name refers to this, and Emuarius shows characteristics of both genera; bearing a crested head like a Cassowary and having a hind-limb structure resembling that of an Emu. The morphology of the legs suggest these birds were adapting to the more open woodland/savannah-like habitat that followed with the Miocene. Like both, it would have been primarily herbivorous but supplemented its diet with small vertebrates. Emuarius remains are known from the Late Oligocene and Early Miocene of Australia.