Fishes evolution

• Gnathostomes

  • Sharks
  • Rays
  • Ray-finned fishes
  • Lobe-finned fishes
  • Amphibians
  • Reptiles
  • Mammals
• Gnathostomes


  Jaws and a lateral line system
• Early gnathostomes in the fossil record

  • Placoderms
  • Acanthodians
• Chondrichthyes


  • Sharks
  • Rays
  • Relatives with skeletons composed mainly of cartilage
• Reproduction modes in Chondrichthyes

  • Oviparous
  • Ovoviviparous
  • Viviparous
• Osteichthyes


  • Actinopterygii
  • Sarcopterygii
• Actinopterygii

  • Ray-finned fishes
• Sarcopterygii


  • Lobe-finned fishes
• Lobe-finned fishes

  • Coelacanths (Actinistia)
  • Living lungfishes (Dipnoi)
• Key evolutionary adaptations

  • Jaws
  • Fins
  • Reproduction modes
  • Dermal structures like scales and mucus