The Cryptobranchoidea are a suborder of salamanders found in Asia, European Russia, and the United States.

[1] It has two living subdivisions, Cryptobranchidae (Asian giant salamanders and hellbenders), and Hynobiidae, commonly known as Asian salamanders.

Giant salamanders are obligate paedomorphs with partial metamorphosis,[2] but Asiatic salamander goes through a full metamorphosis.

The only known exceptions are the Longdong stream salamander, which has been documented as facultatively neotenic, and the Ezo salamander, where a now assumed extinct population from Lake Kuttarush in Hokkaido had neotenic traits like gills in adults.

[3] The oldest members of the group are known from the Middle Jurassic (Bathonian) aged Yanliao Biota of China.