1. Deuterostomes

2. Phylum Echinodermata

6. Water vascular system Starfish moving view from aboral surface Starfish moving view from oral surface

8. Note bilateral larvae!

9. Phylum Chordata

10. Pharyngeal gill slits Dorsal hollow nerve cord Notochord Muscular, post-anal tail Adult Larva (b) Urochordates (a) Cephalochordates (c) Vertebrates Water flow Cross section of embryo Embryo Pharyngeal pouches become gill slits in aquatic vertebrates Phylum Chordata

11. Subphylum Urochordates – sea squirts

12. Subphylum Cephalochordate – lancelets; amphioxus

13. cartilagebone

14. Urochordate larva cephalochordate Drepanaspis – bony skull Jawless fish Cartilaginous fish Lung fish Bony fish

15. Lobe-like fin Limb that can support walking on land Eusthenopteron (~385 mya) Panderichthys (~380 mya) Tiktaalik (~375 mya) Acanthostega (~365 mya) Tulerpeton (~362 mya) Fin to limb evolution