Section 1 Introduction to Vertebrates Chapter 39 Fishes Section 1 Introduction to Vertebrates
Characteristics Phylum Chordata Subphylum Vertebrata Notochord, pharyngeal pouches, dorsal nerve cord, postanal tail Vertebrae- spine Cranium- skull that protects brain Endoskeleton (bone or cartilage)
Vertebrate Classes Class Myxini- hagfish (jawless) Class Cephalaspidomorphi- lamprey (jawless)
Vertebrate Classes Class Chondrichthyes- sharks, rays, skates, & ratfishes
Vertebrate Classes Class Actinopterygii (ray-finned fish)
Vertebrate Classes Class Sarcopterygii (lobe-finned fishes) Lung Fish Coelacanth
Vertebrate Classes Class Amphibia (amphibians- frogs, toads, salamanders)
Vertebrate Classes Class Reptilia (reptiles- turtles, crocodiles, alligators, lizards, & snakes)
Vertebrate Classes Class Aves (birds)
Vertebrate Classes Class Mammalia (mammals)
Vertebrate Evolution 450 million years ago, the first fishes with jaws and paired fins appeared Jaws are thought to have evolved from the first pair of gill arches- the skeletal elements that support the pharynx
Gill Arches
REVIEW!!! What class are the sharks found in? What are gill arches? What do you think the importance of gill arches are?