Structural Differences of Pharynx and Larynx Among Members of the Family Felidae (Mammalia)
Evidences in literature dealing with pharyngeal or laryngeal anatomy of lynxes, big cats, and the cheetah are only scarce. Whereas morphologic features of the upper neck region are well described in the domestic cat, very few investigations examine the larynx1 or the hyoid2 of other members of the felids more closely. Providing anatomic data for diagnostic examination and surgical treatment we investigated upper neck regions or skulls of four jaguars (Panthera onca), two tigers (Panthera tigris), two lions (Panthera leo), two cheetahs (Acinonyx jubatus), and two Eurasian lynxes (Lynx lynx) by means of gross anatomic dissection, histologic staining techniques, and radiographic examination. The most important difference between domestic cats, lynxes, or cheetahs and jaguars, lions, or tigers on the other hand is, that the roaring-species reveal an elastic and collagenous ligament instead of a bony epihyoid. In the examined tigers and jaguars the epihyal ligament bridges the long distance between the delicate and curved stylohyoid and the short ceratohyoid, which, in adult individuals, is situated together with the basihyoid, the thyrohyoid, and the entire larynx far caudal from the position usual in domestic cats. The stylohyoid is connected with the cartilaginous tympanohyoid, which is situated close by the lateral wall of the bulla tympanica. In comparison with the domestic cat, the lynx, and the cheetah, the highly elastic pharyngeal wall and the soft palate of the Panthera species appear elongated in caudal direction. This elongation of the pharynx and the mid-cervical position of the basihyoid and the larynx is only apparent in adults, whereas in newborn individuals of Panthera onca we found the basihyoid near the border between the upper neck and the intermandibular region. Together with special morphologic features of the vocal folds1 the elongation of the pharynx seems to play an important role in sound production of roaring cats.
1. Hast MH. The larynx of roaring and non-roaring cats. J Anat. 1989;163:117–121.
2. Owen R. On the anatomy of the cheetah. Trans Roy Soc Lond. 1835;1:129–136.