Were the necks of Apatosaurus and Brontosaurus adapted for combat?

1. Were the necks of Apatosaurus and Brontosaurus adapted for combat? Michael P. Taylor1*, Mathew J. Wedel2, Darren Naish and3 Brian Engh4. dino@miketaylor.org.uk 1Department of Earth Sciences, University of Bristol, UK. 2College of Osteopathic Medicine of the Pacific and College of Podiatric Medicine, Western University of Health Sciences, Pomona, California, USA. 3National Oceanography Centre, Southampton, University of Southampton, UK. 41522 Charles Avenue, Arcata, California 95521, USA. Artwork: Bob Bakker

2. Apatosaurus louisae (Carnegie Museum)

3. Apatosaurus louisae (Carnegie Museum)

4. Brontosaurus excelsus in Zallinger's mural

5. Brontosaurus excelsus in Zallinger's mural

6. Brontosaurus excelsus in Zallinger's mural

7. Zallinger's Brontosaurus (1947)

8. Knight's Brontosaurus (1897)

9. What exactly is an apatosaurine? Tschopp et al. (2015), Figure 115. Reduced consensus tree obtained by equal weighting. Fifteen OTUs were deleted a posteriori. Numbers at the nodes indicate the number of changes between the two branches departing from the node (for the apomorphy count).

10. What exactly is an apatosaurine? Tschopp et al. (2015), Figure 115. Reduced consensus, apatosaurine section.

11. What exactly is an apatosaurine? Tschopp et al. (2015), Figure 115. Reduced consensus, apatosaurine section.

12. What exactly is an apatosaurine? Tschopp et al. (2015), Figure 115. Reduced consensus, apatosaurine section.

13. What exactly is an apatosaurine? Tschopp et al. (2015), Figure 115. Reduced consensus, apatosaurine section.

14. AMNH 460 … whatever it is

15. What exactly is an apatosaurine? Tschopp et al. (2015), Figure 115. Reduced consensus, apatosaurine section.

16. NSMT-PV 20375 … whatever is is

17. Diplodocus and Apatosaurus (Carnegie Museum)

18. Diplodocus and Apatosaurus (Carnegie Museum)

19. Tokyo apatosaur Kaatedocus Diplodocus Apatosaurus ajax Haplocanthosaurus Brontosaurus excelsus Camarasaurus

20. Tokyo apatosaur Kaatedocus Diplodocus Apatosaurus ajax Haplocanthosaurus Brontosaurus excelsus Camarasaurus

21. Tokyo apatosaur Kaatedocus Diplodocus Apatosaurus ajax Haplocanthosaurus Brontosaurus excelsus Camarasaurus

22. Tokyo apatosaur Kaatedocus Diplodocus Apatosaurus ajax Haplocanthosaurus Brontosaurus excelsus Camarasaurus

23. Brontosaurus excelsus holotype YPM 1980 Cervical ?8

24. Umbaran starfighter

25. Brontosaurus excelsus holotype YPM 1980 Cervical ?8 Cervical ribs robust

26. Brontosaurus excelsus holotype YPM 1980 Cervical ?8 Diapophyses and parapophyses robust Cervical ribs robust

27. Brontosaurus excelsus holotype YPM 1980 Cervical ?8 Cervical ribs displaced ventrally Diapophyses and parapophyses robust Cervical ribs robust

28. Brontosaurus excelsus holotype YPM 1980 Cervical ?8 Cervical ribs displaced ventrally Diapophyses and parapophyses robust Diapophyses and parapophyses project ventrolaterally Cervical ribs robust

29. Brontosaurus excelsus holotype YPM 1980 Cervical ?8 Cervical ribs displaced ventrally Diapophyses and parapophyses robust Diapophyses and parapophyses project ventrolaterally Cervical ribs have anteroventral knobs Cervical ribs robust

30. Knight's Brontosaurus (1897)

35. Why this big, heavy, weird neck? expensive to build, maintain, and operate.

38. Taylor and Wedel (2013a:26) just gave up

39. Taylor and Wedel (2013a:26) just gave up

40. No sex, please, we're sauropods

41. But apatosaurs are different Emiliano Troco

42. But apatosaurs are different John Conway

43. Sexual combat like necking giraffes?

44. Giraffes have crass, uncharismatic, Highly fused mammalian skulls ...

45. … Whereas apatosaurs have elegant, fragile skulls

46. Sexual combat like necking giraffes?

47. ? So what were they doing?

48. 1. Ventral displacement of cervical ribs Improved mechanical advantage of hypaxial muscles.

49. Stronger ventral movements of the neck

50. 2. Ventrolaterally directed parapophyseal rami Oriented to resist ventral impacts