1. Chordates Part 2

2. Transition from Jawless fishes to Jaws:

5. Class- Chondrichthyes (cartilaginous fishes):

6. Have skeleton made of cartilage
Lighter and more flexible than bone
Moveable jaws
Well developed teeth
Mouth is ventral
Tail provides propulsion
Pectoral and pelvic fins produce lift
Buoyancy- oil in large liver
Sink if not swimming
Dermal denticles, scales like teeth, sandpaper skin
Examples: Sharks, rays, skates
100 million years old (living fossils)

16. Class- Osteichthyes (Bony fish):
27,000 species, 98% of all fishes
Skeleton made of bone

17. Thin flexible scales

18. Gill cover or operculum