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A new approach to determining the habitual neck posture of sauropods based on the behaviour of extant animals Michael P. Taylor 1 Mathew J. Wedel 2 Darren.

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Presentation on theme: "A new approach to determining the habitual neck posture of sauropods based on the behaviour of extant animals Michael P. Taylor 1 Mathew J. Wedel 2 Darren."— Presentation transcript:

1 A new approach to determining the habitual neck posture of sauropods based on the behaviour of extant animals Michael P. Taylor 1 Mathew J. Wedel 2 Darren Naish 1 1 Palaeobiology Research Group, School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth PO1 3QL, UK 2 Department of Anatomy and College of Podiatric Medicine, Western University of Health Sciences, 309 E. Second Street, Pomona, California , USA.

2 Historical background The earliest sauropod reconstructions had horizontal necks Camarasaurus (Ryder 1877) Reprinted by Osborn and Mook (1921: plate LXXXII)

3 Historical background The earliest sauropod reconstructions had horizontal necks Brontosaurus (Marsh 1883: plate I)

4 Historical background The earliest sauropod reconstructions had horizontal necks Diplodocus carnegii (Hatcher 1901: plate VIII)

5 Historical background Later sauropod reconstructions had raised necks Camarasaurus (Osborn and Mook 1921: plate LXXXIV)

6 Historical background Later sauropod reconstructions had raised necks Brachiosaurus brancai (Janensch 1950b: plate VIII)

7 Historical background Later sauropod reconstructions had raised necks Brachiosaurus brancai (Paul 1988:fig. 1)

8 Historical background Later sauropod reconstructions had raised necks ?! Brachiosaurus brancai (Paul 1988:fig. 1)

9 Historical background Later sauropod reconstructions had raised necks Brontosaurus (Zallinger's 1947 mural at YPM)

10 Recent work has reverted to horizontal Necks considered low and inflexible Leicester City Museum Cetiosaurus oxoniensis

11 Recent work Necks considered low and inflexible Martin (1987: fig. 2)

12 Recent work Osteological neutral pose (ONP) Stevens and Parrish (2005b: fig. 10.3A) – same specimen

13 Recent work Osteological neutral pose (ONP) Stevens and Parrish (2005a: fig. 6.5B) – Diplodocus carnegii

14 Recent work (Giraffes are different: ONP gives rise to an erect neck) Stevens and Parrish (2005a: fig. 6.2) – Giraffe

15 Recent work Sauropod necks considered low and inflexible Stevens and Parrish (2005a: fig. 6.14) – Diplodocus carnegii

16 Recent work Necks considered low and inflexible Stevens and Parrish (1999: fig. 2B) – Diplodocus carnegii DinoMorph

17 Recent work Necks considered low and inflexible Stevens and Parrish (1999: 798, 800)

18 Recent work Necks considered low and inflexible Stevens and Parrish (1999: 798, 800)

19 Recent work Necks considered low and inflexible Stevens and Parrish (1999: 798, 800)

20 Recent work Necks considered low and inflexible Claim: ONP is sub-horizontal in all sauropods

21 Recent work Necks considered low and inflexible Claim: ONP is sub-horizontal in all sauropods Claim: ONP is the habitual posture

22 Recent work Neck held high Christian and Dzemski (2007) – stress patterns

23 Recent work Neck held high Christian and Dzemski (2007) – stress patterns Similar findings by...

24 Recent work Neck held high Christian and Dzemski (2007) – stress patterns Similar findings by... Christian and Heinrich (1998)

25 Recent work Neck held high Christian and Dzemski (2007) – stress patterns Similar findings by... Christian and Heinrich (1998) Christian (2002a)

26 Recent work Neck held high Christian and Dzemski (2007) – stress patterns Similar findings by... Christian and Heinrich (1998) Christian (2002a) Christian (2002b)

27 Recent work Neck held high Christian and Dzemski (2007) – stress patterns Similar findings by... Christian and Heinrich (1998) Christian (2002a) Christian (2002b) Christian (2004)

28 Recent work Neck held high Christian and Dzemski (2007) – stress patterns Similar findings by... Christian and Heinrich (1998) Christian (2002a) Christian (2002b) Christian (2004) One-man crusade?

29 The state of the art Low necks popularised by the BBC (and AMNH)

30 The state of the art Low necks popularised by the BBC (and AMNH) All based on ONP

31 But

32 What do extant animals do?

33 Habitual posture of extant animals Vidal et al (1986) on unrestrained awake animals Cat, sitting and standing (Vidal et al. 1986: fig. 3)

34 Habitual posture of extant animals Vidal et al (1986) on unrestrained awake animals But what about nice, cuddly bunny-rabbits?

35 Habitual posture of extant animals Nice, cuddly bunny-rabbits have vertical necks, too. Rabbit in semi-alert posture (Vidal et al. 1986: fig. 4)

36 Habitual posture of extant animals And so do rats and guinea pigs Rat and guinea pig (Vidal et al. 1986: fig. 5B-C)

37 Habitual posture of extant animals And so do rats and guinea pigs Rat and guinea pig (Vidal et al. 1986: fig. 5B-C) Is it just mammals?

38 Habitual posture of extant animals What about the humble chicken?

39 Habitual posture of extant animals Chicken necks habitually bend backwards! (Vidal et al. 1986: fig. 7)

40 Habitual posture is not ONP Vidal et al.'s (1986) key findings

41 Habitual posture is not ONP Cervicodorsal joint is maximally extended Vidal et al.'s (1986) key findings

42 Habitual posture is not ONP Cervicodorsal joint is maximally extended Craniocervical joint is maximally flexed Vidal et al.'s (1986) key findings

43 Habitual posture is not ONP Cervicodorsal joint is maximally extended Craniocervical joint is maximally flexed Median part of neck is mostly held rigid Vidal et al.'s (1986) key findings

44 Habitual posture is not ONP Cervicodorsal joint is maximally extended Craniocervical joint is maximally flexed Median part of neck is mostly held rigid The neck is raised and lowered at end joints Vidal et al.'s (1986) key findings

45 Cold-blooded/sprawling amniotes Alligator (Claessens, unpublished photo)

46 Cold-blooded/sprawling amniotes Unspecified lizard (Vidal et al. 1986: fig. 8A) Varanid lizard (Brainerd and Owekowicz 2006: fig. 4)

47 Cold-blooded/sprawling amniotes Turtle (Landberg et al. 2003:fig. 8)

48 Non-amniote tetrapods Salamander (Simons et al. 2000:fig. 4)

49 Neck posture mapped onto cladogram

50 Neck posture mapped onto cladogram

51 Neck posture mapped onto cladogram Upright posture

52 Neck posture mapped onto cladogram Upright posture Homeothermy

53 Diplodocus carnegii (based on Hatcher 1901) (Skull orientation based on occipital condyle)

54 Dicraeosaurus deathmatch! Janensch (1936: plate 16) vs. Wilson (2002: fig. 1)

55 Dicraeosaurus deathmatch! Janensch (1936: plate 16) vs. Wilson (2002: fig. 1)

56 Also... what does neutral actually mean? Modified from Stevens and Parrish (2005b: fig. 6.8) Neutral pose

57 Also... what does neutral actually mean? Modified from Stevens and Parrish (2005b: fig. 6.8) Ventrally deflected by 8°

58 Modified from Stevens and Parrish (2005b: fig. 6.8) Dorsally deflected by 8° Also... what does neutral actually mean?

59 Thanks for listening Visit our blog: Sauropod Vertebra Picture of the Week Your neck (all seven vertebrae) Sauroposeidon C8 (one vertebra)


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