Climacoceratidae

Climacoceratide is a family of artiodactyls which lived in Miocene in Africa. They're closely related to giraffes, with some genera, like "Prolibytherium" previously classified as giraffes.
The climacoceratids, named after one of their members, "Climacoceras", were previously placed in the family Palaeomerycidae, then in Giraffidae. In 1978, W.D. Hamilton made a new family, placing it near Giraffidae in the superfamily Giraffoidea.
They differ from giraffes as their ossicones are from different bones.