4. The Chordates –Dorsal nerve (Spinal) cord –Notochord or backbone/vertebrae –Tail (at some stage of the life cycle) –Muscle Blocks –Gill Slits (at some stage of the life cycle

5. General Chordate Body Plan

6. Characteristics of the Chordates Notochord, dorsal hollow nerve cord, pharyngeal gill slits, blocks of muscle, postanal tail

7. Notochord (flexible rod - mesoderm) Dorsal hollow nerve cord (endoderm) Pharyngeal gill slits (all 3 germ layers) Blocks of muscle Postanal tail

12. Kingdom: Animalia Phylum: Chordata Order: Vertebrata Class: ?

13. Major Classes of Vertebrates Above: Class Amphibia: Includes all amphibians (frogs, toads, salamanders) Below: Class Aves: Includes all birds Above: Class Reptilia: Includes the reptiles Below: Class Mammalia: Includes all mammals

14. Class Chondrichthyes: Includes all cartilaginous fish ex. shark Class Osteichthyes: Includes all bony fish

15. Characteristics of All Vertebrates Coelomate and bilaterally symmetrical which allows for complex body systems Have backbones with a protected spinal column and endoskeleton Advanced central nervous system with large brain with skull Cephalization Complex heart and circulatory systems Muscular system consists of mostly paired masses Possess a special outer covering Have 1 or 2 pairs of appendages Are found on land and water

16. Bony Fishes Skeleton is made up of bone Have a swim bladder to regulate buoyancy Perform external fertilization and lay eggs Have been very successful because they can reproduce in large quantities Cartilaginous Fishes Skeleton is made up of cartilage Do not have a swim bladders Perform internal fertilization and bear live young What’s the Difference?

17. Placoderms

18. Adaptations of Vertebrates Class Amphibia Have gills and very primitive lungs to exchange gasses as they live half of their life in water and half on land Can also take in gasses through their moist skin Lay eggs in the water after sexual reproduction which develop into tadpoles

19. Crocodiles & Snakes Reptiles Turtles & Lizards

20. And Don’t Forget… Dinosaurs were reptiles too!!

21. In addition to the amphibian characteristics, reptiles also had the following characteristics that allowed them to be away from water for longer, move better and grow larger: Dry scaly skin (prevented drying out of skin, but also prevented breathing thru skin) Expandable rib cage (allowed them to inflate their lungs to a large volume)

22. Leather shelled amniote eggs (allowed them to lay their eggs away from water) Copulatory organs (i.e. a penis - for internal fertilization – the only way for sperms to get to eggs when animals are living on land !!) Legs extending beneath the body (for better locomotion & supporting more weight) 3 and 1/2 chamber heart (for better separation of oxygenated and deoxygenated blood – richer blood – more energy)

23. Adaptations of Vertebrates Class Aves : The Birds Adaptations for Flight Feathers 4 chambered heart Hollow bones for strength without weight Large sternum for wings to attach and put pressure Lungs and air sacs are used to improve gas exchange at thin altitudes

24. Birds Improvements over reptiles include: Feathers (for insulation and flight) Hollow bones (lighter weight for flight)

25. Warm blooded (allowing for greater energy production) Air sacs (for greater surface area and gas exchange) 4 chamber heart (for complete separation of oxygenated and deoxyg. blood = richer blood = more energy) Hard shelled amniote egg (more protection from drying out and from predators)

26. Endotherms Warm blooded Body temperature remains constant regardless of external temperature changes Endotherms can regulate their metabolic rate and are more independent of their environments Ectotherms Cold blooded Body temperature varies with the surrounding environment Cannot regulate their metabolic rate very well What’s the Difference?

27. Characteristics of Mammals Warm blooded Air breathing 4 legged vertebrates Possess skin with hair and sweat glands Have teeth with a jawbone Fleshy lips Diaphragm 4 chambered heart Have a brain and middle ear Bear live young Have mammary glands

28. Mammals The Cenozoic Era is known as the “Age of Mammals” In addition to warm blood and a 4 chambered heart, mammals also possess: Milk and Mammary glands (to nourish young) Body hair (for insulation) 3 groups: placentals, monotremes, and marsupials

29. Placentals Possess a placenta which supports the growth of the embryo until birth – better chance of survival

30. Monotremes Lay leathery eggs (like reptiles) Echidna (spiny ant-eater) platypus

31. Marsupials Give birth to an immature live young - no larger than a kidney bean Wombats, opossums, kangaroos, koalas

32. Ecological Roles of Vertebrates All are part of the food chain Amphibians contribute to wetland ecology, prey on insects and devour algae and dead plants Reptiles are predators of pests Birds control insect and vermin populations as well as act as pollinators Mammals aerate soil and are sensitive to environmental changes