Holoaden Holoaden Holoaden (common name: highland frogs) is a small genus of craugastorid frogs endemic to southeastern Brazil. "Holoaden" is the type genus of subfamily Holoadeninae that was erected in 2008 and placed in family Strabomantidae, erected at the same time. Before that, it was in Brachycephalidae. However, later research has led the whole Strabomantidae, Holoadeninae included, to become included in Craugastoridae. This arrangement is not followed by all, and the AmphibiaWeb still keeps Holoadeninae, and consequently "Holoaden", in Strabomantidae. "Holoaden" grow to snout–vent length at most. Head is narrower than the body. Differentiated tympanic membrane and tympanic annulus are absent.
Tympanic nerve Tympanic nerve The tympanic nerve (nerve of Jacobson) is a branch of the glossopharyngeal nerve found near the ear. It arises from the petrous ganglion, and ascends to the tympanic cavity through a small canal, the inferior tympanic canaliculus, on the under surface of the petrous portion of the temporal bone on the ridge which separates the carotid canal from the jugular fossa. In the tympanic cavity it divides into branches which form the tympanic plexus and are contained in grooves upon the surface of the promontory. Jacobson's nerve contains both sensory and secretory fibers. The postganglionic parasympathetic fibers are