Hynobiidae Cope, 1859

The Hynobiidae is a monophyletic family, sister to the Cryptobranchidae. Hynobiids are small to moderatesized salamanders, ranging from about 10 to 20 cm total length. Metamorphosis is complete. Adults have eyelids and no gill slits. Larvae have four pairs of gill slits and caudal fins. The palatal dentition pattern is transverse, not paralleling the maxillary and premaxillary teeth. Hynobiids have an angular bone in the lower jaw, and large numbers of microchromosomes. Fertilisation is external. Eggs are laid in two arc-shaped, gelatinous egg sacs. The present distribution of the hynobiids is entirely Asian, ranging from Siberia westward to the Ural Mountains, southwestward to Turkestan, Afghanistan, and Iran, and southward to China, Korea and Japan, where most members of the family occur. The family Hynobiidae contains approximately 60 species assigned to nine genera: Batrachuperus, Hynobius, Liua, Onychodactylus, Pachyhynobius, Paradactylodon, Pseudohynobius, Ranodon and Salamandrella.Keywords: Batrachuperus; Hynobiids; Hynobius; Liua; Onychodactylus; Pachyhynobius; Paradactylodon; Pseudohynobius; Ranodon; Salamandrella