1. Chordates (Phylum Chordata) 1. Tunicates/Sea squirts 2. Lancelets
II. Vertebrates
Chordates (Phylum Chordata)
1. Tunicates/Sea squirts
2. Lancelets
these 2 do not have vertebrae but have a type of nervous cord along back
3. Vertebrates (Subphylum Craniata)

2. Vertebrate Characteristics
Bony vertebral column
Nerve cord
Cranium - surrounds anterior brain
- bone or cartilage

3. 1. Jawless Fishes (Superclass Agnatha)
a. Hagfish
b. Lampreys

4. 2. Jawed Chordates (Superclass Gnathostoma) paired fins/lungs
Jaws
paired fins/lungs
better fossil record (bones preserve better than soft
tissue
several classes
Modern Fishes
Jawless Ancestors

5. Classes of Gnathostoma Cartilaginous fishes (Class Chondrichtyes)
Sharks and Rays

6. 2. Bony Fishes (Class Osteichthyes)

7. Transition to Land

8. Tiktaalik roseae 375 mya fossil
discovered in 2004 on Ellesmere Island in Cdn Arctic
spent time on land and in water

9. 3. Amphibians (Class Amphibia)
- Salamanders, toads, frogs
- Moist skin
- Oviparous (lay eggs)

10. 4. Reptiles (Class Reptilia)
- Have amniotic egg
- Can lay eggs in dry environments

11. 5. Birds (Class Aves)
beak
feathers
oviparous

12. 6. Class Mammalia - Mammals

13. Mammal Characteristics
1. Skull

14. 2. Hair - keratinized filaments

15. 3. Mammary glands
produce milk to nourish young
derived from sweat glands

16. 4. Teeth

17. 5. Limb position
ventral - positioned under body
- differs from lateral position in ancestors

19. 3 Groups of Mammals
1. Monotremes – oviparous (lay eggs)

20. 2. Marsupials i. primitive placenta
ii. altricial young (carried outside of body)

21. Placentals i. derived/advanced placenta ii. precocial young
(carried inside)
iii. most familiar mammals