Hyoid apparatus and pharynx in the lion ( Panthera leo ), jaguar ( Panthera onca ), tiger ( Panthera tigris ), cheetah ( Acinonyx jubatus ) and domestic cat ( Felis silvestris f. catus ) G AbstractStructures of the hyoid apparatus, the pharynx and their topographical positions in the lion, tiger, jaguar, cheetah and domestic cat were described in order to determine morphological differences between species or subfamilies of the Felidae. In the lion, tiger and jaguar (species of the subfamily Pantherinae) the Epihyoideum is an elastic ligament lying between the lateral pharyngeal muscles and the Musculus ( M .) thyroglossus rather than a bony element like in the cheetah or the domestic cat. The M. thyroglossus was only present in the species of the Pantherinae studied. In the lion and the jaguar the Thyrohyoideum and the thyroid cartilage are connected by an elastic ligament, whereas in the tiger there is a synovial articulation. In adult individuals of the lion, tiger and jaguar the ventral end of the tympanohyal cartilage is rotated and therefore the ventral end of the attached Stylohyoideum lies caudal to the Tympanohyoideum and the cranial base. In newborn jaguars the Apparatus hyoideus shows a similar topographical position as in adult cheetahs or domestic cats. In adult Pantherinae, the Basihyoideum and the attached larynx occupy a descended position: they are situated near the cranial thoracic aperture, the pharyngeal wall and the soft palate are caudally elongated accordingly. In the Pantherinae examined the caudal end of the soft palate lies dorsal to the glottis. Differences in these morphological features between the subfamilies of the Felidae have an influence on specific structural characters of their vocalizations.Key words descensus of larynx; Felidae; pharyngeal muscles; topography; upper vocal tract. IntroductionThe tetrapod hyoid apparatus provides the skeletal scaffolding supporting the tongue, upper vocal tract and larynx, and thus forms the core of the vocal production system. Hyoid anatomy in mammals is very consistent in broad overview, with the number and general shape of segments, and the muscles connecting them, being highly conserved in mammalian evolution. Conceptually these segments can be broken into two divisions (see Fig. 1): the base portion (ceratohyoid, basihyoid and thyrohyoid) which provides a bony support for the tongue rostrally and larynx caudally, and a linkage portion which links the base to the skull (tympanohyoid, stylohyoid and epihyoid). The hyoid apparatus of mammals can vary in the extent to which its constituent parts are ossified, cartilagineous or ligamentous. This variation can occur among different species of the same order (e.g. Rodents, Primates) or family (e.g. Felidae [Carnivora]) and even within the same species such as humans (Fürbringer, 1922;Lykaki & Papadopoulos, 1988;Nakano et al. 1988). The first hint on the peculiarities of the hyoidean apparatus in the carnivoran family Felidae was published by Owen (1835). The main finding in a later survey by Po...

As many veterinarians are equipped with ultrasound machines with 5-8 MHz linear rectal probes, the authors recommend using these probes for further investigation of clinical cases with swelling of the TMJ region and/or masticatory problems of unclear origin to exclude or diagnose TMJ disorders.