1. PHYLUM
CHORDATA

4. PHYLUM CHORDATA Characteristcs of Chordates:
all chordates have 4 characteristics in common at some point in their life cycle:
dorsal, hollow nerve tube: in most adult chordates, the posterior part develops into a spinal cord and the anterior part develops into a brain
notochord: firm flexible tube just below the nerve tube(backbone in vertebrates), where muscles can attach
gill slits: paired openings along the pharynx which functions in filter feeding
post-anal tail: at some point during development, a tail reaches beyond the anus
There are actually 3 subphylums of chordates, 2 of which are invertebrates)

5. The Phylum Chordata Includes:
Subphylum Cephalochordata (=lancelets)
Subphylum Urochordata (= tunicates)
Subphylum vertebrata:
Class Agnatha - jawless fish
Class Amphibia
Class Aves – birds
Class Chondrichthyes - cartilaginous fish
Class Osteichthyes - bony fish
Class Reptilia
Class Mammalia

7. * Efficient respiratory systems
* Only phylum to have bones