PHYLUM CHORDATA SUBPHYLUM VERTEBRATA A SURVEY OF DIVERSITY

1. PHYLUM CHORDATASUBPHYLUM VERTEBRATAA SURVEY OF DIVERSITY BIO 122: Zoology Part 2 Amphibians, Reptiles & Birds

2. CLASS AMPHIBIA Amphibians:include frogs, toads, salamanders & others • Tetrapods (4 legs) • Have a gelatinous egg covering • Have a 3-chambered heart2 atria, 1 ventricle

3. CLASS AMPHIBIA Amphibian development is well known • egg laid in water • hatch into larval forms or tadpoles with gills • lungs and leg develop, tail stops growing with time • adults come out of water

4. CLASS AMPHIBIA

5. CLASS AMPHIBIA • Variations in developmental pattern seen:some remain in water w/ gills: mud puppy, & few salamanders (newts)

6. CLASS AMPHIBIA • Heart is 3-chambered: • atrium is separated into two distinct chambers • blood circulation: body  right atrium & ventricle  lungs  left atrium & ventricle • oxygen rich blood goes out to body, oxygen-poor blood goes to lungs

7. CLASS AMPHIBIA Variation in respiration mechanisms: • gills for aquatic forms • lungs on terrestrial forms • through skin (diffusion) on all forms

8. CLASS AMPHIBIA Breathing in frogs: have lung and mouth pouch • suck air into mouth through nostrils • close nostrils and force air into lungs • pull air into & out of mouth several times (an alternate mechanism to get oxygen) • contracting of body wall to expel air from lungs (this is method to obtain most oxygen) most carbon dioxide lost through diffusion out skin

9. CLASS AMPHIBIA Caecilians - snake-like with no visible appendages • most species lack eyes • food of small animals • most are tropical; are either aquatic or live in burrows

10. CLASS AMPHIBIA Salamanders - have similar front & back legs, a tail • are carnivorous: eat worms, small arthropods • greatest diversity is in North America

11. CLASS AMPHIBIA Frogs and toads - have longer back legs, no tail • tadpoles are herbivorous, adults carnivorous, largest can eat rats! • found throughout world • frogs & toads are not easily separated - typical: frog in water, toad terrestrial

12. CLASS AMPHIBIA • South Carolina state amphibian – spotted salamander

13. CLASS REPTILIA Reptiles:include snakes, lizards, turtles, crocodiles • Tetrapods (4 legs) • leathery egg covering • 3-chambered heart

14. CLASS REPTILIA • Characteristics to separate reptiles from amphibians include …

15. CLASS REPTILIA • lungs more efficient as only mechanism for breathing • reptile suck air into lungs, not force as in amphibians • do so by enlarging pleural cavity or expanding rib cage (no diaphragm present) • no larval stages with gills

16. CLASS REPTILIA • tough, dry, scaly skin • offers protection against desiccation & physical injury • thin epidermis which is shed regularly • well developed dermis with pigmented cells (chromatophores) • scales are of keratin (derived from epidermis)

17. CLASS REPTILIA • egg shell with food and protective membrane • allows for protective development on land

18. CLASS REPTILIA • jaw better able to grip and/or crush • designed for quick closure - larger & longer • amphibian only good to grab

19. CLASS REPTILIA • reptiles have a more efficient circulatory system and higher blood pressure • left & right atrium completely separated • left & right ventricles incompletely separated, but mixing minimal

20. CLASS REPTILIA • reptiles have efficient strategies for water conservation • presence of metanephric kidney (w/ own drainage - ureter) • nitrogenous wastes are uric acid (highly concentrated) • salt glands near nose or eyes

21. CLASS REPTILIA • nervous system more complex • even with small brain, cerebrum is relatively large

22. CLASS REPTILIA Turtles • bony case of dorsal carapace + ventral plastron (shell) • beak rather than teeth • tongue not extensible

23. CLASS REPTILIA Snakes & lizards • skin of scales or plates • teeth present, jaw with diapsid anatomy (allows to open wide) • tongue extensible

24. CLASS REPTILIA Separation of lizards & snakes: • snakes generally lack pectoral and pelvic girdles • snake vertebrae shorter & wider (undulations) • snakes lack a movable eyelid (but have a permanent transparent eyelids)

25. CLASS REPTILIA • Dinosaurs are considered large lizards • Recent studies suggestbirds are descendantsof dinosaurs

26. CLASS REPTILIA Crocodiles (and others) • skin of scales or plates • teeth present, jaw without diapsid anatomy • tongue not extensible • also: 4-chambered heart

27. CLASS REPTILIA • South Carolina state reptile – Loggerhead Sea Turtle

28. CLASS AVES birds • 2 legs + 2 wings • calcareous egg covering • 4-chambered heart

29. CLASS AVES Other important characteristics • body covering: body of feathers; legs of scales • forelimbs modified to wings (or fins?) • beak with no teeth • endothermic (body temperature by metabolism) - previous groups exothermic • females with only left ovary developing • eggs with much yolk and hard calcareous shell

30. CLASS AVES Flight made possible by: • wings - flattened structures to catch air movement • sternum with keel for attachment of flight muscles • bones pneumatized (full of air cavities) • presence of air sacs, extensions of lung into abdomen

31. CLASS AVES air sacs - extensions of lung into abdomen • up to 75% of air bypasses the lungs as breathing in • flows through lungs on way out (more efficient)

32. CLASS AVES • Migration common among many species • Summer nesting grounds, take advantage of abundant food in summer • Winter feeding - migrate to other suitable site Arctic tern with pole to pole migration!

33. CLASS AVES Types of annual migration patterns: • permanent resident - here year round • summer resident - migrate here to breed during warm months • winter resident - summer breeding somewhere else, typically further north • summer or winter visitor - present during only part of year, eg. ocean birds • spring / fall transient - moving through during migration • accidental - strange presence on a very erratic basis

34. CLASS AVES Small species use songs for two reasons1) warns other males to stay away2) attracts prospective females Once female attracted male will display additionally to keep female1) songs2) plumage displays3) dances & acrobatic flights

35. CLASS AVES Superorders: • flightless birds with vestigial wings & stiff palate (ostrich, emu, kiwi) • birds with well developed wings (including penguins) and flexible palate

36. CLASS AVES Orders: • over 20 Orders in eastern North America • Orders are separated by + bill shape (feeding)+ foot shape+ size + other characteristics

37. CLASS AVES

38. CLASS AVES • South Carolina state bird -