1. (coelomates = second mouth)
Deuterostomes
(coelomates = second mouth)

2. Phylum Echinodermata Sea cucmbers Sea stars Sea urchins brittle stars
Feather stars
Sea stars
brittle stars
Sand dollars

3. Echinoderm Ancestral Traits
Coelom
Bilaterally symmetrical larvae
But all adults have radial symmetry
Complete digestive system
(alimentary canal)

4. Retro traits : bringing back the past
Regeneration ability
Radial symmetry: works great for sessile
Seems to work for slow moving creatures too
Only larvae still bilateral (evidence of a bilateral ancestor)
No head or brain
Sensory receptors and nerves spread out in a network around the body
No respiratory, circulatory or excretory system
Diffusion through tube feet

5. Echinoderm Derived Traits
Endoskeleton of hard spiny plates
Covered by thin layer of epidermis
Tube feet (100s of suction cup feet)

6. Sea Star Feeding Sea star pulls a bivalve open using its tube feet
Sea star everts its stomach into the bivalve shell and digests the meat inside
Stomach returns to interior of sea star

7. Phylum Chordata All are deuterostome coelomates
All have bilateral symmetry at some stage of their life

8. 4 key Chordate Characteristics
Dorsal hollow nerve cord
A notochord (skeletal rod) supports the nerve cord at some point in development
Pharyngeal pouches at some point
Post anal tail at some point

10. Tunicates- Subphylum Urochordata
Only larvae have chordate characteristics
Adults sessile filterfeeders

11. Tunicates = sea squirts

12. Subphylum Cephalochordata
Lancelets
Segmented muscles
Tiny filter feeders

13. Subphylum Vertebrata All have cartilagenous/bone endoskeleton
Covers at least the brain (Craniata)
Most have vertebrae to protect the dorsal nerve cord

14. Primitive Chordates = Agnatha (jawless fish)
Hagfish
Lampreys
Ostracoderms
(extinct silurian fish)

15. Superclass Gnathostomata
Jaw mouth = all have jaws
All other fish
All tetrapods

16. Class Chondriththyes Cartilagenous Fish Sharks Skates Rays Triats
No swim bladder
No operculum (must swim to breath)

17. Class Osteichthyes – bony fish
Have bone skeleton
Most have swim bladder
Have operculum over gills

18. Class Amphibia = first Vert. on land
Eggs & larvae in water
Larval respiration gills/skin
Larval circulatory system like
a fish
2 chambered heart
single loop circulatory system

19. Adults move onto land Stronger skeletal system
Respiration by lungs/skin
New type of circulatory system
3 chamber heart
2 loop circulatory system
Evolutionary Advantage to land
No predators
Insects for food

20. Class Reptilia Amniote egg = freedom from water
Scales = prevent dehydration
no O2 from diffusion any longer
Lungs developed folds and pouches
Increased surface area
Heart begins to divide into 4 chambers in crocodillians

21. Class Aves = Birds Amniote eggs Feathers & scales Flight
Endothermic: high metabolism=high energy
Lungs with air pockets – always fresh air
4 chambered heart – no mixing of oxygenated and un-oxygenated blood

24. Class Mammalia Fur/hair & subcutaneous fat Endothermic
Produce milk for offspring
All have amniotic sac but not all are contained in an egg

25. Mammal Amniotes Amniotes of 3 types Monotremes lay eggs
Marsupials babies are born as immature embryos and finish development in pouch
Placental mammals embryos obtain nutrients from their mother through a placenta. Offspring are much more mature when born

26. Amnion membranes