The Chordates
Deuterostome embryo development
Endoskeleton - the major evolutionary step towards large terrestrial animals
- flexible rod along back (dorsal) side of animals
- segmented endoskeleton (vertebral column)
- muscles attached to endoskeleton ? allows to “swing” body side-to-side ? increased mobility
- muscles arranged in segmentation pattern
Two major groups: nonvertebrate chordates and vertebrates