Ossicone:
Ossicones are horn-like (or antler-like) protuberances on the heads of giraffes, male okapis, and their extinct relatives, such as Sivatherium, and the climacoceratids, such as Climacoceras.[1] The base that a deer’s antlers grow from is very similar to an ossicone.
Ossicones are similar to the horns of antelopes and cattle, save that they are derived from ossified cartilage rather than living bone,[2] and that the ossicones remain covered in skin and fur, rather than horny keratin. Antlers (such as on deer) are derived from bone tissue: when mature, the skin and fur covering of the antlers, termed “velvet,” is sloughed and scraped off to expose the bone of the antlers. [Wikipedia]
Noted in “Giraffe ancestor didn’t have a long neck, but two sets of horns,” Science:
Ten years of excavation at a dig site an hour south of Madrid revealed the nearly complete fossil of a newly identified giraffe ancestor species, scientists reported Wednesday in PLOS ONE. Looking more like a moose, the 9-million-year old ancestor lacks the familiar long neck of modern giraffes, The New York Times reported. Instead, the most distinguishing feature of the new species is the presence of two sets of bony protrusions, or ossicones, on the top of the head on both males and females. That means ossicones may not have evolved as a courtship strategy—helping males vie for female attention—as scientists thought.
