Editing Purr (section)

===Degree of hyoid ossification===
No cat can both purr and [[roar (vocalization)|roar]]. The subdivision of the Felidae into "purring cats" ([[Felinae]]) on one hand and "roaring cats" ([[Pantherinae]]) on the other goes back to Owen<ref>{{cite journal|doi=10.1111/j.1096-3642.1835.tb00611.x|title=On the Anatomy of the Cheetah, Felis jubata, Schreb|journal=The Transactions of the Zoological Society of London|volume=1|issue=2|pages=129–136|year=1834|last1=Owen|first1=Richard}}</ref> and was definitively introduced by Pocock,<ref>{{cite journal|doi=10.1080/00222931608693839|title=On the hyoidean apparatus of the lion (F. leo) and related species of Felidæ|journal=Annals and Magazine of Natural History|volume=18|issue=104|pages=222–229|year=1916|last1=Pocock|first1=R.I.|url=https://zenodo.org/record/2453999}}</ref> based on whether the [[hyoid bone]] of the [[larynx]] is incompletely ("roarers") or completely ("purrers") [[ossified]]. However, Weissengruber et al. argued that the ability of a cat species to purr is not affected by the anatomy of its hyoid.<ref>{{cite journal|doi=10.1046/j.1469-7580.2002.00088.x|pmid=12363272|pmc=1570911|title=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)|journal=Journal of Anatomy|volume=201|issue=3|pages=195–209|year=2002|last1=Weissengruber|first1=G. E.|last2=Forstenpointner|first2=G.|last3=Peters|first3=G.|last4=Kubber-Heiss|first4=A.|last5=Fitch|first5=W. T.}}</ref>

The "roaring cats" (lion, ''Panthera leo''; tiger, ''P. tigris''; jaguar, ''P. onca''; leopard, ''P. pardus'') have an incompletely ossified hyoid, which, according to this hypothesis, enables them to roar but not to purr. However, the [[snow leopard]] (''Uncia uncia'', or ''P. uncia''), as the fifth felid species with an incompletely ossified hyoid, purrs.<ref>{{cite journal|doi=10.2307/3503882|jstor=3503882|title=Uncia uncia|journal=Mammalian Species|issue=20|pages=1–5|year=1972|last1=Hemmer|first1=Helmut|doi-access=free}}</ref>

All remaining species of the family Felidae ("purring cats") have a completely ossified hyoid, which enables them to purr but not to roar. Based on a technical acoustic definition of roaring, the presence of this vocalization type depends on specific characteristics of the vocal folds and an elongated vocal tract, which  is rendered possible by an incompletely ossified hyoid.