Some  other thoughts on mollusk origins

Annelids or  flatworms
Trochophore larvae

Arthropods

  1. segmented--tagmata
  2. jointed appendages
  3. exoskeleton
  4. complete digestive tract
  5. open circulatory system
  • Kinds of arthropods
  • spiders
  • ticks
  • mites
  • centipedes
  • millipedes
  • crustaceans
  • hexapods
  • horseshoe crabs
  • trilobites

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