Why giraffes have such short necks

1. Why giraffes have such short necks Michael P. Taylor Mathew J. Wedel

2. Why giraffes have such short necks … and how sauropods got it right Michael P. Taylor Mathew J. Wedel

18. 3-meter barrier for all non-aquatic animals

19. Long-necked sauropod groups Upchurch et al. (2004:fig. 13.18)

20. Long-necked sauropod groups Upchurch et al. (2004:fig. 13.18)

21. Long-necked sauropod groups Upchurch et al. (2004:fig. 13.18) I suck ...

22. Long-necked sauropod groups Upchurch et al. (2004:fig. 13.18) Magic I suck ...

23. Factors contributing to long necks 1. No constraint on vertebral count Paraceratherium (Osborn 1923:fig 1)

24. Factors contributing to long necks 1. No constraint on vertebral count Paraceratherium (Osborn 1923:fig 1) Mamenchisaurus (modified from Ouyang and Ye 2003:fig. 13)

25. Factors contributing to long necks 2. Heads that did not process food

26. Factors contributing to long necks 2. Heads that did not process food Diplodocus

27. Factors contributing to long necks 3. Heads that did not process food Unholy Diplodocus ☓ Elephas hybrid

28. Factors contributing to long necks 3. Absolutely large bodies

29. Factors contributing to long necks 3. Absolutely large bodies

30. Factors contributing to long necks 3. Absolutely large bodies C Crap.

31. Factors contributing to long necks 3A. Large quadrupedal bodies C Crap.

32. Factors contributing to long necks 3A. Large quadrupedal bodies C Crap.

33. Factors contributing to long necks 3A. Large quadrupedal bodies C Crap.

34. Factors contributing to long necks 3. Absolutely large bodies Parrish (2006) showed that sauropod neck length scales with torso length to the power 1.35

35. Factors contributing to long necks 3. Absolutely large bodies Carpenter (2006) scaled Amphicoeliasfragillimus as 2.2 times Diplodocus. But Parrish suggests neck is 2.2^1.35 = 2.9 times => a neck 22 m long

36. Factors contributing to long necks 4. Air-sacs overcame dead-space

37. Factors contributing to long necks 4. Air-sacs overcame dead-space Like ostriches?

38. Factors contributing to long necks 4. Air-sacs overcame dead-space But what about sperm whales? Paul 1998:fig. 11

39. Factors contributing to long necks 4. Air-sacs overcame dead-space But what about sperm whales? Paul 1998:fig. 11

40. Factors contributing to long necks 5. Vertebral architecture Diplodocus carnegii holotype CM 84, cervical 10 (Hatcher 1901:plate III)

41. Cervical vertebral innovations 1. Extreme pneumaticity 2. Bifid neural spines 3. Elongate cervical ribs

42. Cervical vertebral innovations 1. Extreme pneumaticity Ostrich

43. Cervical vertebral innovations 1. Extreme pneumaticity Diplodocus

44. Cervical vertebral innovations 1. Extreme pneumaticity Diplodocus modified from Paul 1998:fig. 1(a)F

45. Cervical vertebral innovations 1. Extreme pneumaticity Diplodocus cervical cross-sections Paul 1997:fig. 4 Schwarz et al. 2007:fig. 7A2

46. Cervical vertebral innovations 1. Extreme pneumaticity Diplodocus

47. Cervical vertebral innovations 1. Extreme pneumaticity Diplodocus

48. Cervical vertebral innovations 1. Extreme pneumaticity Diplodocus

49. Cervical vertebral innovations 1. Extreme pneumaticity Red tailed hawk

50. Cervical vertebral innovations 2. Bifid neural spines Apatosaurus