25.1 Vertebrate Origins KEY CONCEPT All vertebrates share common characteristics.
FISHIES Classes: Agnatha, Chondrichthyes, and Osteichthyes.
Introduction to Fish. Phylum Chordata Subphylum Vertebrata – Class Agnatha – Class Chondrichthyes – Class Osteichthyes – Class Amphibia – Class Reptilia.
Biology Kingdoms
