| A | B |
| phylum including vertebrates, tunicates, and lancelets | Phylum Chordata |
| subphylum including tunicates | Subphylum Urochordata |
| subphylum including lancelets | Subphylum Cephalochordata |
| subphylum including fish, amphibians, reptiles, birds, and mammals | Subphylum Vertebrata |
| class including jawless fish | Class Agnatha |
| class including cartilage fish | Class Chondrichthyes |
| class including bony fish | Class Osteichthyes |
| class including amphibians | Class Amphibia |
| class including reptiles | Class Reptilia |
| class including birds | Class Aves |
| class including mammals | Class Mammalia |
| order including frogs and toads | Order Anura |
| order including salamanders | Order Urodela |
| order including turtles and tortoises | Order Chelonia |
| order including snakes and lizards | Order Squamata |
| order including alligators and crocodiles | Order Crocodilia |
| mammals that lay shelled eggs | monotremes |
| mammals develop in an external pouch | marsupials |
| mammals develop in a placenta | plancental mammals |
| order including bats | Order Chiroptera |