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 I suck... Upchurch et al. (2004:fig. 13.18)

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

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 Mamenchisaurus (modified from Ouyang and Ye 2003:fig. 13) Paraceratherium (Osborn 1923:fig 1)

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

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

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

39. C Factors contributing to long necks 3A. Large quadrupedal bodies 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 Amphicoelias fragillimus 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 Diplodocus carnegii holotype CM 84, cervical 10 (Hatcher 1901:plate III) Neural spine Prezygapophysis Post- zygapophysis Cervical rib Centrum

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

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

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

53. Cervical vertebral innovations 1. Extreme pneumaticity Diplodocus

54. Cervical vertebral innovations 1. Extreme pneumaticity Diplodocus

55. Cervical vertebral innovations 1. Extreme pneumaticity Diplodocus

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

57. Cervical vertebral innovations 2. Bifid neural spines Apatosaurus

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

59. Long-necked sauropod groups Bifid neural spines evolved at least five times Never secondarily lost? Otherwise found only in the rhea (and only just) Upchurch et al. (2004:fig. 13.18)

60. Cervical vertebral innovations 2. Bifid neural spines Alexander (1985) thought the trough was filled with a giant elastin ligament Diplodocus

61. Cervical vertebral innovations 2. Bifid neural spines Apatosaurus

62. Cervical vertebral innovations 2. Bifid neural spines Apatosaurus

63. Cervical vertebral innovations 2. Bifid neural spines Apatosaurus

64. Cervical vertebral innovations 2. Bifid neural spines Diplodocus (Schwarz et al. 2007:fig. 7A2)

65. Cervical vertebral innovations 2. Bifid neural spines

66. Cervical vertebral innovations 2. Bifid neural spines

67. Cervical vertebral innovations 2. Bifid neural spines

68. Cervical vertebral innovations 3. Elongate cervical ribs Turkey cervical 7

69. Cervical vertebral innovations 3. Elongate cervical ribs Turkey cervical 7

70. Cervical vertebral innovations 3. Elongate cervical ribs 4.1 m Turkey cervical 7 Mamenchisaurus

71. Cervical vertebral innovations 3. Elongate cervical ribs 4.1 m Mamenchisaurus That lame giraffe Turkey cervical 7

72. Cervical vertebral innovations 3. Elongate cervical ribs Giraffatitan

73. Cervical vertebral innovations 3. Elongate cervical ribs Giraffatitan

74. Cervical vertebral innovations 3. Elongate cervical ribs Giraffatitan

75. Comparison with birds and crocs Turkey cervical 7

76. Comparison with birds and crocs Turkey cervical 7

77. Comparison with birds and crocs Turkey cervical 7 Epipophysis

78. Comparison with birds and crocs Turkey cervical 7

79. Comparison with birds and crocs AlligatorMajungasaurusTurkey Majungasaurus from O'Connor 2007:figs. 8, 20

80. Comparison with birds and crocs AlligatorMajungasaurusTurkey Majungasaurus from O'Connor 2007:figs. 8, 20

81. Comparison with birds and crocs AlligatorMajungasaurusTurkey Majungasaurus from O'Connor 2007:figs. 8, 20

82. Comparison with birds and crocs AlligatorMajungasaurusTurkeyGiraffatitan Giraffatitan from Janensch 1950:fig. 46 Majungasaurus from O'Connor 2007:figs. 8, 20

83. Comparison with birds and crocs AlligatorMajungasaurusTurkeyGiraffatitanCamarasaurus Giraffatitan from Janensch 1950:fig. 46 Camarasaurus from Osborn and Mook 1921:plate LXVII Majungasaurus from O'Connor 2007:figs. 8, 20

84. Comparison with birds and crocs Analogous but not homologous AlligatorMajungasaurusTurkeyGiraffatitanCamarasaurus Giraffatitan from Janensch 1950:fig. 46 Camarasaurus from Osborn and Mook 1921:plate LXVII Majungasaurus from O'Connor 2007:figs. 8, 20

85. Why are epipophyses not elongate? Euhelopus (Wiman 1929:plate III)

86. Why are epipophyses not elongate? Euhelopus (Wiman 1929:plate III)

87. Why are epipophyses not elongate? Euhelopus (Wiman 1929:plate III)

88. Why are epipophyses not elongate? Euhelopus (Wiman 1929:plate III)

89. Why are epipophyses not elongate? Deinonychus (Ostrom 1969:fig. 37)

90. Why are epipophyses not elongate? Giraffatitan (Janensch 1950:fig. 43)

91. Why are epipophyses not elongate? Need finer control for precise movements – requires shorter levers Giraffatitan (Janensch 1950:fig. 43)

92. Why are epipophyses not elongate? Tendon is stronger in tension than bone Giraffatitan (Janensch 1950:fig. 43)

93. Why are epipophyses not elongate? Muscles expand when they contract lengthways Giraffatitan (Janensch 1950:fig. 43)

94. Why are epipophyses not elongate? Muscles expand when they contract lengthways Giraffatitan (Janensch 1950:fig. 43)

95. Why are epipophyses not elongate?

96. Crap.

97. Conclusion TaxonMany vertebrae Small head (no dental battery) Large body, four legs Air-sacsPneumatic vertebrae Elongate cervical ribs Giraffe Giant rhinos ✓ Ostrich ✓✓✓✓ Theropods ✓✓✓ Pterosaurs ✓✓ Sauropods ✓✓✓✓✓✓

98. Conclusion TaxonMany vertebrae Small head (no dental battery) Large body, four legs Air-sacsPneumatic vertebrae Elongate cervical ribs Giraffe X XXXXX Giant rhinos ✓ Ostrich ✓✓✓✓ Theropods ✓✓✓ Pterosaurs ✓✓ Sauropods ✓✓✓✓✓✓

99. Acknowledgements Everyone who allowed us access to specimens Everyone that we stole images from Western University for sending Matt to the UK Sauroposeidon

100. Further reading Sauropod Vertebra Picture of the Week: http://svpow.com/ Taylor and Wedel 2013a: https://peerj.com/articles/36https://peerj.com/articles/36 Email: dino@miketaylor.org.uk Sauroposeidon