An opening of the otic duct within the inner ear. The recessus basilaris can open to the saccule (in frogs) or the lagena (in salamanders and caecilians). The sensory epithelium of the recessus basilaris is the basilar papilla (or papilla basilaris). Reference: Lewis, E.R. and R.E. Lombard. 1988. The amphibian inner ear. Pp. 93-123 in Fritszch, B., et al. (eds.), The Evolution of the Amphibian Auditory System. Wiley & Sons. [curated by D. Blackburn] [ ]