1. Deuterostomate Animals
Embryonic blastopore becomes the anus.
Three body layers.
True coelom.
Dorsal nerve cord.

3. Echinodermata Spiny exterior Calcified internal skeleton
Bilateral symmetry in larvae, but often radial symmetry in adults
Water vascular system for mobility, gas exchange, and feeding.
system of internal tubes and canals
tube feet that can exert strong suction

6. Phylum Chordata Pharyngeal slits (gill slits in neck)
Hollow dorsal nerve cord
Ventral heart
Post-anal tail
Dorsal supporting rod, the notochord
Many of these may become obscure or absent in later development of the organism.

7. Invertebrate Chordates
Tunicates – tadpole-like larva has chordate features; adults are sessile
Lancelets – notochord throughout life

8. Vertebrates Notochord replaced by vertebral column
two pairs of appendiages
anterior skull
well-developed circulatory system
closed system (blood leaves heart and returns to heart in closed vessels)