vertebrates

• Vertebrates


  Animals with a backbone
• Derived characters of chordates


  • Notochord
  • Dorsal, hollow nerve cord
  • Pharyngeal slits
  • Post-anal tail
• Characteristics of different chordate groups


  • Head
  • Vertebrae
  • Jaws
  • Bony skeleton
  • Lobed fins
  • Limbs with digits
  • Amniotic egg
• Chondrichthyes


  Jawed cartilaginous fish

  
• Actinopterygii


  Ray-finned fishes
• Craniates


  • Chordates with a head
  • Derived characters: skull, brain, eyes, sense organs, higher metabolism
• Vertebrates


  Craniates with a backbone
• Gnathostomes


  Vertebrates with jaws
• Osteichthyans


  Gnathostomes with bony endoskeleton
• Sarcopterygians


  Lobe-finned fishes (Actinistia - Coelacanth, Dipnoi - Lungfish)

  
• Tetrapods


  • Sarcopterygians with limbs
  • Derived characters: four limbs with digits, neck, fused pelvic girdle, ears for airborne sounds
• Amphibians


  Tetrapods with simple eggs and jelly coat
• Amniotes


  • Tetrapods with amniotic eggs
• Reptiles


  • Amniotes with scales, shelled eggs laid on land
  • Include lizards, snakes, turtles, crocodilians, birds, extinct dinosaurs
• Two main clades of reptiles


  • Lepidosaurs (tuataras, lizards, snakes)
  • Archosaurs (crocodilians, extinct dinosaurs, birds)
• Extinct reptiles


  • Archosauria
  • Pterosaurs
  • Dinosaurs (Ornithischians, Saurischians)
• Dinosaurs - Aves (birds)


  Saurischian dinosaurs with derived characters: forelimbs develop into wings, keratinized feathers, hollow skeletons, loss of teeth
• Birds


  • Emu (ratite)
  • Hummingbird
  • Flamingo
  • Penguin
  • Passeriformes
• Mammals


  • Amniotes with hair
  • Derived characters: mammary glands, hair, high metabolic rate, large brain, differentiated teeth
  • Three main groups: Monotremes, Marsupials, Eutherians
• Monotremes


  • Platypus
  • Echidna
• Marsupials


  • Kangaroo
  • Koala
  • Tasmanian devil
• Convergent evolution in mammals (analogy)