1. Invertebrate Chordates
Hemichordata
Urochordata
Cephalochordata

2. Hemichordates
Deuterostomes
Gill slits
Dorsal nerve cord

3. Classes of Hemichordates
Enteropneusta
Acorn worms
Shallow marine animals
Pterobranchia
Rhabdopleura
Colonial, send out feeding zooids

4. Acorn Worm

5. Phylum Chordata All chordates are deuterostomes
At some time in their life, all chordates have:
Notochord
Pharyngeal gill slits
Dorsal, hollow nerve cord
Postanal tail

6. Subphylum Urochordata
Sea squirts or tunicates
Larvae show the characteristics of chordates
Adults lose notochord, nerve cord, and tail
Only animals to have cellulose in their bodies!

7. Tunicates: Are filter feeders Do not have complex nervous systems
Often form large colonies
Are monoecious

8. Tunicate Larva

9. Adult tunicates

10. Subphylum Cephalochordata
Lancelets (Amphioxus)
Notochord runs from head through tail
Muscles can contract the notochord
Live partially buried in marine sediment
Filter feeders
Dioecious