1. A Phylogeny of the Animal Phyla
Porifera
No true tissues
Cnidaria
radial symmetry
diploblastic
Ctenophora
Platyhelminthes
Acoelomates
Rotifera
Pseudocoelomates
Nematoda
Nemertea
Mollusca
Protostomes
true tissues
Annelida
Arthropoda
Bilateral symmetry
triploblastic
Bryozoa
Lophophorate phyla
Body cavity
Phoronida
Coelomates
Brachiopoda
Echinodermata
Chordata
Deuterostomes

2. Echinodermata - the starfish, urchins, sea cucumbers, sand dollars

3. Echinodermata - the starfish, urchins, sea cucumbers
Description
Echinoderms are
• deuterostomes
• have a water vascular system
• have hardened plates (ossicles) in their epidermis
• pentaradial symmetry

4. General anatomy of a starfish

5. General anatomy of a starfish
Ring canal
Anus
Cardiac stomach
Madreporite
Ossicles
Stone canal
Pyloric stomach
Ring canal
Radial canal
Tube foot
Mouth
Ampulla

6. Echinodermata - the starfish, urchins, sea cucumbers
Water vascular system
- a closed system of canals that echinoderms use for locomotion

7. Echinodermata - the starfish, urchins, sea cucumbers
Water vascular system
- a closed system of canals that echinoderms use for locomotion

8. Echinodermata - the starfish, urchins, sea cucumbers
Water vascular system
- by using water pressure echinoderms can crawl along by moving individual “tube feet” along their bodies

9. Echinodermata - the starfish, urchins, sea cucumbers
Water vascular system
- by using water pressure echinoderms can crawl along by moving individual “tube feet” along their bodies
Ampullar muscles
To extend foot
Longitudinal muscles
1) Flex ampullar muscle
2) Relax longitudinal muscle
3) Flex circular muscles
Circular muscles

10. Echinodermata - the starfish, urchins, sea cucumbers
Ossicles

11. Echinodermata - Who are they?
Asteroidea - Sea stars (starfish)
- active predators, with small ossicles in their epidermis

12. Echinodermata - Who are they?
Echinoidea - Sea urchins
- grazers, with ossicles fused to form a test

13. Echinodermata - Who are they?
Echinoidea - Sand dollars
- grazers, with ossicles fused to form a test

14. Echinodermata - Who are they?
Holothuroidea - Sea cucumbers
- bottom feeders, with very reduced (or absent) ossicles

15. Taxa we have looked at so far
Phylum
Class
Order
Porifera
Calcarea
Demospongia
Hexactinellida
Platyhelminthes
Turbellaria (free-living)
Trematoda (flukes)
Cestoda (tapeworms)
Mollusca
Polyplacophora (chitons)
Gastropoda (snails,slugs)
Bivalvia (clams, oysters)
Cephalopoda (octopus, squid)
Annelida
Oligochaeta (earthworms)
Hirudinea (leeches)
Polychaeta (marine worms)
Arthropoda
Chelicerata (spiders, mites, scorpions)
Myriapoda (centipedes, millipedes)
Uniramia (insects)
Crustacea (crayfish, lobsters, crabs, barnacles)

16. Taxa we have looked at so far
Phylum
Class
Order
Echinodermata
Asteroidea (Sea stars [=starfish])
Echinoidea (sea urchins, sand dollars)
Holothuroidea (sea cucumbers

17. Diversity of Life - Chordata-

18. Chordata - lancets, sea squirts, vertebrates
Description
Chordates are deuterostomes, with a dorsal hollow nerve cord, gill slits, a post-anal tail and a notochord

19. Chordata - Chordate evolution - Ancestral forms - Lancet
Chordata - Chordate evolution - Ancestral forms - Lancet Worms (Amphioxus)
Nerve cord
Notochord
Myomeres

20. Chordata - Chordate evolution - Ancestral forms - Lancet
Chordata - Chordate evolution - Ancestral forms - Lancet Worms (Amphioxus)

21. Sea Squirts - Urochordates (Tunicates)

22. Sea Squirts - Urochordates (Tunicates)

23. Sea Squirts - Urochordates (Tunicates)

24. Chordate Phylogeny (so far)
Cephalochordata
(Amphioxus)
Craniata
Urochordata
(tunicates)

25. Chordata - Chordate Evolution
Chordates acquire over time:
A distinct head - Craniates (most are extinct)
A backbone
Jaws

26. Chordata - Chordate Evolution
Today

27. Chordata - Chordate evolution - Craniates
One surviving group - hagfish - head but no backbone

28. Chordata - Chordate evolution - Craniates
One surviving group - hagfish - Scavengers

29. Chordata - Chordate evolution - Vertebrates - craniates with a backbone
Jawless vertebrates - Agnatha - Lamprey

30. Chordata - Chordate evolution - Vertebrates - craniates with a backbone
Jawless vertebrates - Agnatha – Lamprey - fish parasites

31. From Craniate to Vertebrate
Fibrous sheath
Notochord
Hagfish
Cartilage
Lamprey
Bone
Gnathostomes

32. Next time: Fish and more….