Caudata
Most generalized body form _ short body, with four functional limbs.
- Deviations _ elongated body, with reduced limbs
- Amphiuma, Siren, Pseudobranchus
Body size: 30 mm (Thorius) to 1.5-1.8 m (Andrias)
Most species are terrestrial, but are aquatic breeders.
- Some completely aquatic or completely terrestrial
- Some arboreal species in New World tropics.