Anatomy of the hyoid musculature in the snow leopard ( Panthera uncia )

Abstract

The snow leopard (Panthera uncia) is currently considered vulnerable by the IUCN, with approximately 5,000 individuals left in the wild with a 20% decline in their population in the last two decades. The hyoid apparatus of this felid has been documented, but the musculature of this region has not. The hyoid region of snow leopards is of interest because they have an incompletely ossified hyoid apparatus and they produce distinctive vocalizations among the Felidae. Similar to other pantherines, the snow leopard can elongate the vocal tract by moving the larynx away from the oral cavity to produce lower‐pitched sounds. In this study, we dissected, documented in detail, and imaged the hyoid apparatus and musculature in two adult P. uncia specimens (1M/1F). Our results indicate that the occipitohyoideus, found in numerous carnivorans and felids, is not present in the snow leopard, instead it may be fused with the stylohyoideus. In lions, the sternohyoideus and sternothyroideus both take origin from the second sternebra, however in P. uncia, these muscles take origin from the second sternebra and the first and second rib. The omohyoideus is absent in the snow leopard, not unlike the condition seen in other feliformes. The geniohyoideus is not fused in the midline, which is similar to the condition seen in the tiger. The stylohyoideus inserts on the stylohyoideum via a fascial band, similar to the tiger and the serval. Our initial results suggest that the hyoid musculature of the snow leopard displays unique features, which may shed light on its unique vocalizations.

The roar of Rancho La Brea? Comparative anatomy of modern and fossil felid hyoid bones

“…Weissengruber et al (2002) have suggested that this elastic ligament may allow for a lower laryngeal position, which is correlated with lower frequency vocalizations in other species (Tecumseh Fitch & Reby, 2001). Despite having a similarly unossified epihyoid, the fifth member of the monophyletic genus, Panthera uncia , is unable to either purr or roar; this has been attributed to differences in other soft‐tissue anatomy (Assar et al, 2021; Hast, 1989; Peters & Hast, 1994). All cats within the subfamily Felinae, are able to purr and have fully ossified epihyoid bones (Peters & Hast, 1994; Peters, 2002).…”