The axolotl is one example of a paedomorphic animal. The gills of the salamander area juvenile trait, which the axolotl retains into adulthood. Photo from:Dalton, S. (n.d.). Mexican Axolotl. National Geographic. Retrieved December 1, 2013, from http://animals.nationalgeographic.com/ani
The life cycle of two populations of the northwestern salamander (Ambystoma gracile). From Vertebrates: Comparative Anatomy, Function, Evolution (3rd ed.) by Kenneth Kardong (pg 195)
Paedomorphism is the retention of juvenile traits once an individual individual obtains sexual maturity.
Amphibians[]
Paedomorphism can be found in many salamander populations and species, which have lost their terrestial forms in favor of their aquatic ones.