| Noun | 1. | animal order - the order of animals amphibia, class Amphibia - the class of vertebrates that live on land but breed in water; frogs; toads; newts; salamanders; caecilians family Salamandridae, Salamandridae - salamanders Ambystomatidae, family Ambystomatidae - New World salamanders Cryptobranchidae, family Cryptobranchidae - large aquatic salamanders: hellbenders; giant salamanders family Proteidae, Proteidae - mud puppies Dicamptodontidae, family Dicamptodontidae - large and small highly aquatic salamanders family Plethodontidae, Plethodontidae - small mostly terrestrial New World salamanders having neither lungs nor gills as adults Amphiumidae, family Amphiumidae - congo snakes family Sirenidae, Sirenidae - sirens |