HYOID STRUCTURE, LARYNGEAL ANATOMY, AND VOCALIZATION IN FELIDS (MAMMALIA, CARNIVORA, FELIDAE)

Two types of hyoid structure are found in the Felidae. In five species it contains a cartilaginous ligament, in all other species it is completely ossified. Traditionally, it has been hypothesized that the presence or absence of roaring and purring in the acoustic repertoires of Felidae is correlated with these differences in the structure of the hyoid. This character complex has been used as a major criterion in the systematics of the Felidae. The present study brings together all currently available data to test this hypothesis, and discusses new findings on laryngeal anatomy with respect to vocalization and the hyoidean apparatus in the family Felidae. In the Felidae an incompletely ossified hyoid does not automatically cause a species' ability to roar as this vocalization is restricted to only three of the five species with this hyoid type. All felid species which have been proven to purr have a completely ossified hyoid, but definitive evidence of this vocalization is still lacking in many species with this type of hyoid. Therefore, it is not possible at present to decide whether a fully ossified hyoid automatically causes a species' ability to purr. A further type of vocalization is restricted to those four felid species with a vocal fold morphology differing from that of all other species of the family.