Why giraffes have short necks …

1. Why giraffes have short necks … Michael P. Taylor University of Bristol dino@miketaylor.org.uk Mathew J. Wedel Western University of Health Sciences mathew.wedel@gmail.com

2. Why giraffes have short necks … … and how sauropods got it right Michael P. Taylor University of Bristol dino@miketaylor.org.uk Mathew J. Wedel Western University of Health Sciences mathew.wedel@gmail.com

24. 3-meter barrier for all non-aquatic animals

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

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

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

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

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

30. 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)

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

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

33. Factors contributing to long necks 2. Heads that did not process food Unholy Diplodocus ☓ Elephas hybrid

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

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

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

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

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

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

40. 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

41. 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

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

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

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

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

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

47. Factors contributing to long necks 5. Vertebral architecture Neural spine Prezygapophysis Post- zygapophysis Centrum Cervical rib Diplodocus carnegii holotype CM 84, cervical 10 (Hatcher 1901:plate III)

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

49. Cervical vertebral innovations 1. Extreme pneumaticity Ostrich

50. Cervical vertebral innovations 1. Extreme pneumaticity Diplodocus