Cranial Appendages of Giraffoidea

Abstract

Giraffes and okapi belong to the superfamily Giraffoidea. For the purpose of this essay the Giraffoidea includes ruminant artiodactyls from Eurasia and Africa, dating from Miocene to Recent times. They are characterized by skin-covered indeciduous bony horns or ossicones, at least one pair being borne over the frontoparietal suture, with other paired or unpaired frontonasal ossicones or unpaired nuchal or lateral subsidiary bony outgrowths (Fig. 1). The ossicones condense separately within dermal tissue external to the skull roof and lengthen by intercalarygrowth at the base and superficial to the skull roof. Both males and females may bear ossicones, or females may lack them, or both sexes may be without ossicones. An additional character is the bifid and sometimes trifid crowns of the lower incisive canines.