1. I. Kingdom Animalia
A. Most land animals in 3 phyla:
1. Arthropoda
2. Mollusca
3. Chordata

2. B. Features (general)
1. diploid individuals
2. haploid gametes
- swimming sperm
3. not the “alternation of generations” seen in plants

3. Burgess Shale in Yoho National Park, BC, Canada
About 500 million years old

4. II. Evolutionary Innovations
A. Multicellularity
1. subkingdoms
a. Parazoa
- no symmetry or tissues
b. Eumetazoa

5. 2. simplest animals exhibit only multicellularity
- sponges

6. a. sponges lack tissues and organs
b. “blob” of specialized cells
- choanocytes (collect the food)
- amoebocytes (deliver the food)
- choanocytes are very similar to choanoflagellates (living Protists)
c. intracellular digestion

7. B. Symmetry and tissues
1. embryonic layers (3)
- each layer develops into specialized tissues
a. endoderm
- gastrointestinal tract
b. mesoderm
- muscles, bones
c. ectoderm
- external coverings, nervous system

8. 2. radial symmetry

9. 3. extracellular digestion
4. simplest: cnidarians
a. polyps (mostly sessile)
- sea anemones
- hydras
- many coral animals

10. Coral polyps

11. Sea anemones

12. b. medusae (free-swimming)
- marine jellys

13. Purple jelly

14. Lion’s mane jelly

15. c. some alternate stages as part of their life cycle

16. C. Bilateral symmetry
- right and left (mirror images)
- anterior/posterior
- dorsal/ventral

18. 1. no body cavity around gut (gastrovascular cavity)
- no anus

19. 2. flat worms (solid worms)
a. Phylum Platyhelminthes
b. free-living flatworms (planaria)

21. c. flukes (animal parasites)
d. tapeworms

23. D. Body cavity (pseudocoelom filled with fluid)
- pseudocoelomates
1. allows for:
a. circulation
- especially of nutrients
b. movement
- provides rigid structure to which muscles attach and are anchored for contraction
- hydroskeleton
c. organ function
- organs can function during muscle contraction

24. 2. pseudocoelom is between endoderm and mesoderm

25. 3. nematodes
a. have complete digestive tract

26. b. many are parasitic
- heartworms
- Trichinella (trichinosis)

27. E. Coelom
1. body cavity formed within mesoderm
- allows endoderm to stay in contact with some mesoderm
2. gut tube is again enclosed by tissue
- how do nutrients reach the tissues outside of the gut?
- circulatory system

28. 3. simplest: mollusks

29. a. gastropods (snails and slugs)
- mostly marine
- some terrestrial (are the only terrestrial mollusks)

30. b. cephalopods
- large brains and complex sense organs

31. c. bivalves
- most are sessile

32. c. bivalves
- most are sessile

33. - some can “swim” by “flapping” their shell
sea scallop

34. F. Segmentation
- subdivision of the body into a series of repeated parts
1. annelids
a. repeated segments
b. some segments contain specialized structures
c. segments “connected” by nerves and blood vessels

35. 2. several types
a. earthworms
b. polychaetes
- mostly marine
- Christmas tree worms
- tubeworms

36. c. leeches
- most actually eat small invertebrates

37. 3. still apparent examples of segmentation in higher species
- embryo

38. 3. still apparent examples of segmentation in higher species
- embryo
- vertebrae

39. G. Jointed appendages/exoskeleton (made of chitin)
- Arthropods

40. G. Jointed appendages/exoskeleton (made of chitin)
- Arthropods
1. chelicerates:
a. horseshoe crabs

41. G. Jointed appendages/exoskeleton (made of chitin)
- Arthropods
1. chelicerates:
a. horseshoe crabs
b. arachnids (scorpions, spiders, mites, ticks)

42. 2. millipedes and centipedes
a. millipedes
- herbivores
- two pair of legs per segment
b. centipedes
- poisonous carnivores (insectivores)
- one pair of legs per segment

43. 3. crustaceans
- lobster/crayfish

45. krill
barnacles

46. 4. insects (Class Insecta is by far the largest)
a. head, thorax, abdomen
b. three pair of legs
c. most have 1 or 2 pair of wings

47. H. Chordates (Phylum Chordata)
1. features: (some may be embryonic only)
a. notochord: flexible rod along back
b. nerve cord along back
c. pharyngeal slits
d. post-anal tail

48. 2. invertebrate chordates
- tunicates
- lancelets

49. 3. vertebrates
a. head (with skull to protect brain)
b. backbone (except hagfish: has head but lacks a backbone)
- encloses the nerve (spinal) cord
c. internal skeleton
- bone (usually)
- cartilage (sharks and rays)