KINGDOM ANIMAL PHYLUM: CHORDATA SUBPHYLUM: VERTEBRATA VERTEBRATES ANIMALS WITH: Dorsal nerve cord Hollow backbone Ventral heart 5 major classes Classified by: Skin covering Heart chambers Reproduction Type of limbs How they maintain body temperature HOMOLOGOUS STRUCTURES show relationships Chondrichthyes Sharks, rays Skin covering: teeth Two chambered heart External or internal fertilization Limbs fins Cold blooded, aquatic Skate egg capsule For a bowl of soup, we alter the ecosystem Ostheicthyes Bony fish ectothermic (cold blooded), aquatic vertebrates. skin is covered with scales. limbs - fins for swimming. breathe with gills. External fertilization - lay eggs that must be in water. AMPHIBIANS FROGS, TOADS, NEWTS, SALAMANDERS ectothermic vertebrates. skin is either smooth (like a frog) or rough (like a toad). dependent upon moisture and subject to desiccation; their skin must remain moist to aid in breathing lay eggs in water, which hatch into an intermediate life form (tadpole or larva) that usually breathes with gills, and change into the adult form that breathes air and can live outside water. three-chambered hearts. lack claws on their toes. frog Cane toad NEWT RED SPOTTED NEWT SALAMANDER REPTILES Snakes, lizards, turtles, gators ectothermic vertebrates. skin has scales, but no hair or feathers. three-chambered hearts (except for alligators and crocodiles, which have four- chambered hearts). claws on their toes first animals, in evolution, to develop the amniotic egg. This allows reptiles to lay eggs on land. Amnionic Egg (shelled egg) copperhead rattlesnakes Pygmy rattlesnake BIRDS endothermic vertebrates. skin is covered with feathers. four-chambered hearts. bones are lightweight and usually hollow. forelimbs are modified as wings. lay eggs. MAMMALS endothermic vertebrates. Body covered with hair, which varies greatly among species. Most have sudoriferus (sweat) glands. have mammary (milk-secreting) glands. sebaceous (fat-secreting) glands. have heterodont dentition (different types of teeth). Egg laying mammals Pouched Mammals