Metamorphosis is incomplete in the Cryptobranchidae, leading to a number of paedomorphic characteristics in adults. Morphology of the skull Premaxilla consists of separated, paired bones. Maxillary bones are present and well developed. Septomaxillary bones are absent. Lacrimal bone is absent.
Quadratojugal bone is absent.
Pterygoid bones are present. Internal carotid foramina are absent from parasphenoid bones. The angular bone is separated from the mandible. Ear bones include a detached columella but no operculum. Replacement of vomerine teeth proceeds laterally in parallel to the maxillary teeth.