Chordates

1
Chordates
2
Fish

• Most numerous and widespread
• 3 classes jawless, cartilaginous and bony
• Gills, 2 chambered heart
• Jawless - Agnatha
• Eel-like bodies, cartilage skeletons
• Lampreys and hagfish
• Damage to commercial fisheries
• Cartilaginous Chondrichthyes
• Sharks, skates, rays
• Biting jaws and paired fins
• Bony Osteichthyes
• Most numerous
• Trout, cod,
• Swim bladder

3
Class Amphibia

• Legless, tailless, tailed
• 2 lives eggs/tadpoles aquatic, adult
  terrestrial
• 3 chambered heart, skin and simple lungs for
  breathing
• Sensitive to contaminants (indicators of aquatic
  and terrestrial health)
• http//news.nationalgeographic.com/news/2006/01/01
  12_060112_frog_climate.html

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Class Reptilia

• First fully terrestrial vertebrates
• Found in most warm habitats
• Sub-classes Anapsida (turtles), Lepidosaura
  (lizards/snakes), Archosaura (crocodiles,
  alligators, dinosaurs)
• Dry waterproof skin, efficient lungs and
  circulation, 3 chamber heart with some ventrical
  separation, amniotic egg, stronger bones and
  muscles, limb repositioning, forward knees

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Birds - Aves

• Feathers for insulation and protection
• Lungs and air sacs efficient gas exchange for
  high alts and energy requirements of flight
• Hollow bones, 4 chambered heart, no urinary
  bladders, good vision, rapid digestion

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Class mammalia

• Reptile ancestor
• Took advantage of dinosaur extinction
• Diversity size
• Bony skeleton, bilateral symmetry
• Monotremes, marsupials, placental mammals (95)
• Complex brain, endothermic (adapted to almost
  every climate, opposable thumb
• 4 legged, warm-blooded, air-breathing, hairy
  skin, sweat glands, 4 types of teeth, fleshy
  lips, diaphragm, four-chambered heart, middle
  ear, viviparous, mammary glands, pentadactyl