context: All three of these species have keratin shells covered in keratin on their heads which grow with age. The shape and size of the casque, up to 18 cm (7.1 inches), depends on the species. Casuarius casuarius has the largest form and the smallest Casuarius bennetti (tricorn form), with Casuarius unappendiculatus having variations in between. Contrary to previous findings, the inside of the casque is stretched with fine fibers that are believed to have acoustic functions. [16] Several functions for casque have been proposed. One of them is that they are secondary sexual characteristics. Other suggested functions include being used for dough through shrubs, as a weapon in dominance disputes, or to get rid of side waste while foraging. The last three are debated by biologist Andrew Mack, y
question: what is the name of the largest cassowary species?
answers.text: Casuarius casuarius