Jawless, cartilagenous skeleton, notocord present, lacks paires appendages, 2 chambered heart

Lamprey and Hagfish

Cartilagenous skeleton, jaws,paired appendages, gills, no operculum, no swim bladder, internal fertilization, placoid scales, 2 chambered heart.

Sharks, skates, rays, chimearas

Bony skeleton, jaws, external fertilization, swim bladder, operculum, ctenoid scales, 2 chambered heart.

Bass, trout, perch, tuna

Appendages adapted for land use,tadpole stage, respiration through lung/skin, smooth moist skin, 3 chambered heart.

Salamanders, newts, frogs, toads

Scaly skin, respiration via lungs, lay amniotic egg Partially divided septum.

Snakes, lizards, turtles, crocodiles

Feathers, forelimbs modified as wings, respiration though lungs, endothermic, 4 chambered heart, amniotic egg.

Owls, sparrow, penguins, eagles

young nourished by mammary glands, diaphragm, 4 chambered heart, hair, endothermic, viviparous

Monotremes, marsupials, and Placentals.