1. Anatomic Diversity  Human anatomy is a typical anatomy of a member of Phylum Chordata.  Human anatomy understood biologically within its comparative and developmental contexts.  Understanding the development of vertebrate (in this case human) anatomy is necessary to understand the adult anatomy across vertebrates.

2. Phylum Chordata  Notochord = stiff connective tissue rod  Dorsal hollow nerve cord (neural tube) = hollow nerve cord dorsal to notochord (spinal cord + brain in us)  Endostyle/thyroid = gland involved in iodine metabolism  Pharyngeal Openings (gill openings) = openings into “throat,” behind mouth  Post-anal tail

3. Phylum Chordata Subphylum Urochordata Subphylum Cephalochordata Subphylum Myxini Subphylum Vertebrata Phylum Chordata Urochordata Cephalochordata (lancelets) Vertebrata (vertebrates) pharyngeal openings notochord, neural tube, post-anal tail, endostyle/thyroid, Myxini (hagfishes)

4. Subphylum Urochordata  Sea Squirts, Salps, & Larvaceans  Suspension feeders  Tadpole larva with notochord in tail.

5. Sea Squirt Metamorphosis

6. Subphylum Cephalochordata  Lancelets (Amphioxus, Branchiostoma)  Suspension feeders  Notochord extends into head & includes skeletal muscle cells.  Chordate derived characteristics obvious.

7. Chordate Synapomorphies notochord dorsal nerve tube pharyngeal basket (slits) post-anal tail anus intestine hepatic diverticulum

8. Phylum Chordata Urochordata Cephalochordata (lancelets) Vertebrata (vertebrates) pharyngeal openings notochord, neural tube, post-anal tail, endostyle/thyroid, Myxini (hagfishes) notochord extends into head tadpole larva segmental muscles

9. Lancelet Musculature Musculature Lancelets, hagfishes, & vertebrates have segmental muscles (myotomal muscles). segmental muscles (myotomal muscles)

10. Lancelet Tail Section notochord nerve tube myotomal muscles

11. Lancelet Structure Sketch on board.

13. Craniata  Hagfishes and vertebrates. SYNAPOMORPHIES  Cranium (cartilage or bone)  Liver  Calcium phosphate in skeleton  Neural crest tissue (Developmental)  Neurogenic placodes (Developmental)

14. Phylum Chordata Urochordata Cephalochordata (lancelets) Vertebrata (vertebrates) pharyngeal openings notochord, neural tube, post-anal tail, endostyle/thyroid, Myxini (hagfishes) notochord extends into head segmental muscles

15. Craniate Phylogeny Myxini (hagfishes) lampreys sharks, rays, etc. Actinopterygii coelacanths lungfishes amphibians Mammalia Reptilia liver, CaPO4, neural crest, neuro. placodes

16. Hagfishes, Subphylum Myxini  43 species; marine scavengers  no jaws  lack functional eyes, tentacles, & one naris  serially hermaphroditic  lack bone (cartilage)  secrete slime

17. Hagfish Anatomy  Cartilage under brain and in mouth apparatus.  Keratinous tooth plates.  No real vertebrae.

18. Hagfishes, Subphylum Myxini tentacles caudal fin pharyngeal openings mouth

19. Hagfishes, Class Myxini

20. Hagfish Slime

21. Subphylum Vertebrata  Approximately 50,000 species.  Vertebrates arose in the marine enviro. SYNAPOMORPHIES  Dorsal Fin with skeletal supports  Vertebrae – complete neural arches

22. Vertebrae

23. Craniate Phylogeny Myxini (hagfishes) lampreys sharks, rays, etc. Actinopterygii coelacanths lungfishes amphibians Mammalia Reptilia dorsal fin, complete neural arches

24. Lampreys  Class Petromyzontida  41 species  Oral disc with “teeth” & rasping “tongue”  Ammocoete larva - VERY similar to cephalochordates in way of life  Larvae undergo metamorphosis.  Marine and freshwater ectoparasites (adults) and suspension feeders (larvae)

25. Lampreys, Class Petromyzontida pharyngeal openings eye oral disc dorsal fins 1 narial opening keratinous “teeth”

26. Lampreys, Class Petromyzontida adult ammocoete larva

27. Lamprey, ammocoete notochord neural tube pharyngeal basket (slits & bars) post-anal tail endostyle Sketch on board. anus intestine liver heart brain – spinal cord

29. Lab Activity  Obtain a slide of a lamprey ammocoete and a dissection microscope.  Examine the slide on the microscope.  If appropriate, date the page in your lab notebook and sketch the ammocoete. Label all the parts you labeled on the previous slide.  Ask your instructor if you have difficulty.  Examine the whole preserved lampreys.

30. Lab Activity  Obtain a slide of a cross sectioned ammocoete larva and a compound microscope.  Find the section through the post-anal tail and examine the slide on the microscope.  Sketch the tail section. Label the notochord, myotomal muscles, & neural tube.  Ask your instructor if you have difficulty.

31. Gnathostomata  gnatho- = jaws; stoma = mouth  jawed vertebrates  pectoral & pelvic fins  Myelinated nerves

32. Craniate Phylogeny Myxini (hagfishes) lampreys sharks, rays, etc. Actinopterygii coelacanths lungfishes amphibians Mammalia Reptilia jaws, myelin, paired limbs Gnathostomata

33. Sharks, Rays, Chimaeras, etc.  chondro- = cartilage; ichthys = fish  Sharks, rays, sawfishes, & chimaeras  Males have pelvic claspers.  marine (and freshwater) carnivores  Approx. 850 species

34. Class Chondrichthys

35. Osteichthys  osteo- = bone; ichthys = fish  “bony” vertebrates, NOT just FISHES  bony endoskeleton, lung(s)  ray-finned fishes, lungfishes, the coelacanth, & terrestrial vertebrates

36. Craniate Phylogeny Myxini (hagfishes) lampreys sharks, rays, etc. Actinopterygii coelacanths lungfishes amphibians Mammalia Reptilia bony endoskeleton, lung(s) Osteichthys

37. Class Actinopterygii  actino- = ray; ptery = fin or wing  ray-finned fishes  marine and freshwater  24,500+ species (= the number of species of all other vertebrates put together)  Very diverse in habits and body form.

38. 24,000 species+ sturgeons & paddlefish gars bowfin Amia calva TELEOSTS reedfishes Class Actinopterygii single, dorsal lung

39. Sarcopterygii  sarco- = flesh; ptery = fin or wing  fleshy & bony pectoral and pelvic axis  lobe “fins” (NOT just FISHES)  lungfishes, coelacanths, & terrestrial vertebrates

40. Craniate Phylogeny Myxini (hagfishes) lampreys sharks, rays, etc. Actinopterygii coelacanths lungfishes amphibians Mammalia Reptilia “lobes” Sarcopterygii

41. Coelacanths  2 species  deepwater marine (East Africa & Indonesia)

42. Lungfishes  6-9 species, Tropical freshwaters  unique morphology  Paired ventral lungs

43. Tetrapoda  tetra- = four; poda = foot  “terrestrial” vertebrates  pectoral and pelvic limbs with digits 1 1 2 2 3 4

44. Craniate Phylogeny Myxini (hagfishes) lampreys sharks, rays, etc. Actinopterygii coelacanths lungfishes amphibians Mammalia Reptilia Tetrapoda limbs with digits

45. Amphibians  amphi = both/double, bios = life frogs, toads, salamanders, caecilians  Usually distinct metamorphosis  Approx. 5,000 species  freshwater and terrestrial (none marine)  mucus covering skin

46. Amphibians

47. Amniota  Amnion = amniotic membrane  Amniotic membrane surrounds embryo (in egg or in uterus)  amniotes = reptiles & mammals  Very distinct from other vertebrates

48. Craniate Phylogeny Myxini (hagfishes) lampreys sharks, rays, etc. Actinopterygii coelacanths lungfishes amphibians Mammalia Reptilia amnion Amniota

49. Class Mammalia  Mammals  Named for mammary glands  Hair (no exceptions)  Approx. 4000 species  Most diverse = rodents and bats. monotremes marsupials eutherians hair, mammary glands nipples Theria

50. Monotremes  Platypus & Echidnas  Australia & New Guinea.  Lay eggs  Young lap up milk from nipple-less mammary glands

51. Baby Platypus

52. Echidnas

53. Marsupials  Metatherians  Australia, New Guinea, & S. America  Morphologically diverse in Australia  Do not lay eggs, young develop in an external pouch.  Milk from nipples

54. Eutherians  “Placental” mammals  Worldwide, Very diverse morphologically  Do not lay eggs; young do not develop in an external pouch.  Milk from nipples.

55. Class Reptilia  Turtles, lizards, snakes, tuataras, crocodylians, & birds  Birds ARE reptiles  Thick keratin scales  Approx. 15,000 species  Many extinct turtles lizards & snakes crocodilians birds epidermal scales of beta keratin

56. Turtles  Turtles, tortoises, & terrapins  Worldwide, <1000 species  Ribs and vertebrae form a “shell” (test).  No teeth, keratinous “beak”  Lay eggs.

57. Lepidosaurs: Lizards & Snakes  Lizards, snakes, & tuataras  Worldwide  5000+ species

58. Subclass Archosauria Crocodilians  Alligators, crocodiles, caimans, and gavials  about approx. 40 species

59. Subclass Archosauria Birds  Aves  9,000 species  Feathers, no teeth, keratin beak