The recessus amphibiorum is oriented horizontally in the inner ear. The otic sac is multilobate, vascularized and filled with calcium. Fibrous connective tissue is present around the amphibian periotic canal. The periotic cistern is small. The periotic cistern may or may not protrude into the fenestra.
Lungs are present but greatly reduced in some species.
An ypsiloid cartilage is present. Larvae have four pairs of gill slits and large external gills. The scapula and coracoid bones of the pectoral girdle are fused to form the scapulocoracoid. Vertebral centra are opisthocoelous. Ribs are bicapitate.