Phylum Chordata

1. Phylum Chordata Charactertistics of Chordates All chordates possess a notochord. Long felxable rod between gut & nerve cord Runs most of length of animal Possess a dorsal, hollow, nerve cord Possess pharangeal slits Muscular post-anal tail

2. Urochordates • Subphylum Urochordata • Commonly called turnicates • Sessile marine animals as adults - Motile as larva • Larva possess a clear notochord which is less evident in adults • Filter feed through use of siphon

3. Subphylum Cephalochordata • Commonly known as lancets • Have all features of the ideal chordate • Bury selves in sand, and filter-feed through mouth

4. Phylum Chordata: The Vertebrates • Subphylum Vertebrata • Seven extant classes • First 3 commonly called fishes • Remaining 4 called tetrapods (4 feet) • All possess some form of segmented vertebra

5. Class Agnatha • Commonly known as Jawless Fish • Include hagfish & Lampreys • Lack paired appendages • Lack bony skeleton • Lack jaws • Usually have circular sucking mouthparts • Lampreys parasitize other fish

6. Lampreys

7. Hagfish

8. Class Chondrichthyes • Include sharks & skates, & rays • Very successful class • Called cartilagenous fishes because skeleton is cartilage not bone • Approx. 750 species • Have paired appendages • Many have acute senses • Sharks have a lateral-line system • Allows shark to detect water pressure changes

9. Sharks

10. Noteworthy Shark Species Great White Shark Tiger Shark Whale Shark Bull Shark

11. Rays & Skates Southern Stingray Manta Ray Skates

12. Class Osteichthes • Called Bony fish • Most diverse of all fish • Have skeleton made of bone • Have Cycloid Scales • Have paired fins • Allowed evolution of 4 limbed amphibians (tetrapods) • Possess scales for protection • Have bony flap called operculum • Allows water to be drawn over gills by fins • Have Swim bladder • Gas content can be manipulated allowing for changes in bouyancy

13. Bluefish

14. Class Amphibia • First vertebrates to inhabit land • Most are 4 limbed (tetrapods) • Include frogs, salamanders & caecilians • Have 3 chambered heart • Have more complicated gas exchange organs (often a combination of lungs, gills and skin)

15. Order Urodela(Salamanders & Newts) • Urodela ("tailed ones" - Salamanders) • More dependent on water • Many species possess gills as adults

16. Class Apoda ("tail-less ones" - Frogs & toads) • Have more developed lungs than salamanders • Lack a diaphragm & must “swallow” air • Most diverse and common of amphibians. • Toads are the first amphibians to evolve keratinized skin. • This waterproofs the skin preventing water loss • Toads must still return to water to lay eggs.

17. Common North American Frogs North American Toad Green Frog Bullfrog Poison Arrow Frog Leopard Frog Peepers

18. Caecilia ("legless ones")

19. Reproduction • Lack internal fertilization & amniotic eggs • Reproduction must occur in H2O • Most species undergo metamorphosis • Larval stage (tadpole) is usually an aquatic herbavore • Lacks legs, respiration is through gills • Develops into tetrapod adult (usually carnivorous)

20. Class Reptilia • Includes lizards, snakes, turtles, and crocodilians • Over 7000 species • Possess several advanced features over amphibians • Most adaptations towards independence from H2O • Possess scales containing keratin • Keratin is a waterproofing protein which prevents water loss in an organism • Possess an amniotic egg. • Prevents water loss of embryo. Allows for eggs to be laid on dry land • Combined with internal fertilization, allows reptiles to reproduce independently of water • Reptiles are "cold blooded" or ectotherms • Cannot internally regulate body temperatures • Reptiles can regulate body temperatures behaviorally (eg. Basking or swimming) • Nutritional requirements are lower than warm blooded animals

21. The Amniotic Egg

22. Modern Reptiles • Order Chelonia (Turtles & Tortoises) • Inhabit aquatic and terrestrial environment. • Are herbavores, carnivores, and omnivores • Characterized by possessing a hard dorsal shell • Made from bone, extensions of backbone and rib cage

23. Common North American Turtles

24. Order Squamata • Order Squamata (Lizards & Snakes) • Most numerous & diverse of the reptiles • Most relatively small Although monitors and their relatives can grow to 6' in length • Herbivores, carnivores & omnivores • Most able to exhibit some form of hibernation

25. Noteworthy Lizards Komodo Dragon Eastern Fence Lizard Anole Leopard Gecko

26. North American Snakes

27. Order Crocodilia(Crocodiles, Alligators, & Caimans) • Largest extant reptiles can grow to over 15’ and weigh over a ton • Primarily aquatic they are true reptiles • Inhabit warm, tropical climates • Order most closely related to the dinosaurs

28. Crocodilians Crocodile Alligator Gavail Caiman

29. Class Aves(The Birds) • Evolved from dinosaurs during Mezozoic era. • Aminotic eggs and scales on legs reminants of reptilian origins • Almost all adaptations of these animals are made for flight. • Presence of feathers • Made of keratin • Can be used for insulation and flight • Forelimbs developed into wings • Honeycombed, light bone structure

30. Feathers

31. Beak Types • Absence of some organs • Females usually have 1 ovary • Absence of teeth lighten head • Replaced by gizzard in abdomen & beak • Beak made of keratin • Proven very adaptable structure, having a variety of shapes for differing diets

32. Reproduction • Reproduction is through hardened amniotic eggs • Since birds are endothermic, these must be kept warm by parents • This behavior called brooding

33. Birds Feet

34. Modern Birds • Over 8600 species & 20 orders of birds • Classified into 2 general groups • Flightless species including ostrich, emus, & kiwis are known as ratites • Lack sternal keel on breastbone • Lack strong breast muscles needed for flight Ostrich: A ratite

35. Modern birds contd. • Other species capable of supporting flight called carinates • 60% are "perching birds" called passeriforms • Possess a sternal keel on breastbone • Support strong breast muscles required for flight The sparrow: A passeriform carinate

36. Class mammalia • Approx. 4500 species of mammals • Evolved from mammal-like reptiles called therapsids in the triassic period • Diversified greatly following the extinction of dinosaurs • Mammilian Characteristics • Have Hair • Made of keratin • Aids in maintaining body temperature • Endothermic • Maintain body temperature internally • Have efficient respiratory system including a diaphragm • Efficient circulatory system with a 4-chambered heart • Most possess placentas and give birth to live young • Have mammary glands to produce milk for offspring • All show parental care of offspring • Have largest brains of all vertebrates • Have differentiated teeth • Unlike earlier vertebrates, several different teeth can exist in mammal jaws • Eg. The molars & incisors in the human jaw

37. General Types of Mammals • Monotremes • Early branch from reptilian line • Include platypuses & echidnas (spiny anteaters) • Only group to lay eggs (reptilian in structure) • Have mammary glands to feed young Duck Billed Platypus Echidna

38. Marsupials • Include opossums, kangaroos & koalas • Mostly found in Australia & New Zealand • Were isolated in these landmasses when the continents separated and did not evolve li the same way placental mammals did • Do not develop placentas • Give birth to young very early • Fetuses complete development in pouch called marsupium • Mammary glands found in pouch nourish young until development is complete

39. Examples of marsupials Koala Opossum Kangaroo

40. Placental Mammals • Complete embryonic development in uterus • Joined to parent by organ called placenta • Only "disposable" mammal organ • Discarded following birth • Exchanges gasses, nutrients & waste between mother and fetus

41. Common North American Mammals 1

42. Common North American Mammals 2