As well as male okapi and the extinct relatives of both. Ossicones are not antlers or horns, in that they are not made of bone or horn but rather ossified ("bonelike") cartilage, and they remain covered in skin and fur.
Coined from Latin roots os, bone (or rather its combining form ossi-) + cōnus, cone (originally, apex of a helmet). Also, though I'm sure you don't need me to point this out, it's a lovely word to say. Ossicones!