A. Prototherian mammals
B. Metatherian mammals
C. Eutherian mammals
D. Reptilia

A. Prototheria
B. Metathena
C. Eutheria
D. Reptilia

A. Amphibians and fishes
B. Amphibians and reptiles
C. Amphibians and birds
D. Reptiles and birds

A. Amphibia
B. Osteichthyes
C. Agnatha
D. Reptilia

A. Reptilia
B. Amphibia
C. Chondrichthyes
D. Osteichthyes

A. Amphibians
B. Reptiles
C. Fishes
D. Molluses

A. Fishes
B. Reptiles
C. Cephalochordates
D. Amphibians

A. Reptiles
B. Agnatha
C. Amphibians
D. Urochordates

A. Agnatha
B. Chondrichthyes
C. Osteichthyes
D. Reptiles

A. Agnatha
B. Chondrichthyes
C. Osteichthyes
D. Reptiles