Steller's sea cow
As with all sirenians, the sea cow's snout pointed downwards, which allowed it to better grasp kelp. The sea cow's nostrils were roughly long and wide. In addition to those within its mouth, the sea cow also had stiff bristles long protruding from its muzzle. Steller's sea cow had small eyes located halfway between its nostrils and ears with black irises, livid eyeballs, and canthi which were not externally visible. The animal had no eyelashes, but like other diving creatures such as sea otters, Steller's sea cow had a nictitating membrane, which covered its eyes to prevent injury while feeding. The tongue was small and remained in the back of the mouth, unable to reach the masticatory (chewing) pads.