Da Silva (1998) did not include vocal sac
architecture as one of his characters but this character must represent some sort of homoplasy, given his cladogram.
The next day seven males called from water; these males moved around the pond with all legs extended and the black lateral vocal sacs inflated.
Cei (1980) reported that vocal sacs resemble white balloons on either side of the head.
For the diagnoses, the following numbered elements do not exhibit variation: (1) skin of venter areolate or granular; no dorsolateral folds; (4) upper eyelid broader than IOD, no cranial crests; (6) males with large subgular vocal sac
, no nuptial pads; (7) first finger shorter than second; (9) no ulnar tubercles; (10) no tubercles or folds on heel or tarsus; (11) no supernumerary plantar tubercles; (12) fifth toe much longer than third.
Stanley Rand concluded in 1993, so they dismissed the idea of vocal sacs
as resonating cavities.
Dorsum, chest, and gula smooth; belly skin granular; vocal sac
prominent tending to be bilobed when inflated; an incomplete chest fold, folds of skin at wrist, knee and heel; axillary membrane small.
To beat their competitors in the fight for females, these tiny frogs have a built-in volume control: an inflatable vocal sac
(balloonlike pouch) beneath the mouth.