the bones of the sternum become completely ossified in 23 to 25 years.
when do the bones of the sternum become completely ossified?
23 to 25 years
na
na
it was once believed that only the cats of the genus "felis" could purr. however, felids of the genus "panthera" (tigers, lions, jaguars and leopards) also produce sounds similar to purring, but only when exhaling. the subdivision of the felidae into 'purring cats' on the one hand and 'roaring cats' (i.e. non-purring) on the other, originally goes back to owen (1834/1835) and was definitely introduced by pocock (1916), based on a difference in hyoid anatomy. the 'roaring cats' (lion, "panthera leo"; tiger, "p. tigris"; jaguar, "p. onca"; leopard, "p. pardus") have an incompletely ossified hyoid, which according to this theory, enables them to roar but not to purr. on the other hand, the snow leopard ("uncia uncia"), as the fifth felid species with an incompletely ossified hyoid, purrs (hemmer, 1972). all remaining species of the family felidae ('purring cats') have a completely ossified hyoid which enables them to purr but not to roar. however, weissengruber et al. (2002) argued that the ability of a cat species to purr is not affected by the anatomy of its hyoid, i.e. whether it is fully ossified or has a ligamentous epihyoid, and that, 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, the latter rendered possible by an incompletely ossified hyoid. cats may purr for a variety of reasons, including when they're hungry, happy, or anxious.
cat communication