Major Phyla of Animals - Focus on Invertebrates

1. Porifera
2. Cnidaria - Jellies
3. Platyhelminthes - flatworms
4. Mollusca - clams, snails, etc
5. Annelida - Segmented worms
6. Nematoda - Roundworms
7. Arthropada - Insects, crustaceans, etc
8. Echinodermata - Seastars, etc
9. Chordata - Vertebrates, etc

Evolution of the Animal Body Plan

• All animals have a body plan (architectural pattern), overall organization of organism
• 5 Key transactions can be noted in animal evolution
  1. Tissues
  2. Symmetry
  3. Body Cavity
  4. Embryonic Development
  5. Segmentation

Evolution of the Animal Body Plan - Symmetry

Asymmetry

• Sponge and Amoeba

Radial Symmetry

• Tiger
• Body parts arranged around central axis
• Central Point and get 2 equal halves