Cryptobranchoidea

Cryptobranchoidea Temporal range: Middle Jurassic - PresentBathonian–Present PreꞒ Ꞓ O S D C P T J K Pg N
Cryptobranchus alleganiensis
Hynobius fossigenus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Urodela
Suborder:	Cryptobranchoidea Dunn, 1922
Subgroups
†Chunerpeton? †Jeholotriton †Pangerpeton †Nesovtriton? †Iridotriton? †Kiyatriton? †Laccotriton †Sinerpeton Cryptobranchidae Panhynobia Ji, Anderson & Gao, 2021 †Liaoxitriton †Linglongtriton †Neimengtriton †Regalerpeton †Nuominerpeton Hynobiidae

The Cryptobranchoidea are a suborder of salamanders found in Asia, European Russia, and the United States. They are known as primitive salamanders, in contrast to Salamandroidea, the advanced salamanders.^[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.^[4]