TaylorEtAl2008 sauropod neck posture

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					     A new approach to determining
 the habitual neck posture of sauropods
based on the behaviour of extant animals

                         Michael P. Taylor1
                         Mathew J. Wedel2
                          Darren Naish1




   1Palaeobiology  Research Group, School of Earth and Environmental Sciences,
University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth PO1 3QL, UK
 2Department  of Anatomy and College of Podiatric Medicine, Western University of
   Health Sciences, 309 E. Second Street, Pomona, California 91766-1854, USA.
              Historical background
The earliest sauropod reconstructions had horizontal necks




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




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




      Diplodocus carnegii (Hatcher 1901: plate VIII)‫‏‬
           Historical background
  Later sauropod reconstructions had raised necks




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




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




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




                                                        ?!

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




 Brontosaurus (Zallinger's 1947 mural at YPM)‫‏‬
Recent work has reverted to horizontal
       Necks considered low and inflexible




  Leicester City Museum Cetiosaurus oxoniensis
         Recent work
Necks considered low and inflexible




       Martin (1987: fig. 2)‫‏‬
                   Recent work
            Osteological neutral pose (ONP)‫‏‬




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




Stevens and Parrish (2005a: fig. 6.5B) – Diplodocus carnegii
                   Recent work
(Giraffes are different: ONP gives rise to an erect neck)‫‏‬




    Stevens and Parrish (2005a: fig. 6.2) – Giraffe
                     Recent work
       Sauropod necks considered low and inflexible




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




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




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




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




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




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




Claim: ONP is sub-horizontal in all sauropods
     Claim: ONP is the habitual posture
              Recent work
               Neck held high




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


                       Similar findings by ...




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


                       Similar findings by ...
                       Christian and Heinrich (1998)‫‏‬




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


                       Similar findings by ...
                       Christian and Heinrich (1998)‫‏‬
                       Christian (2002a)‫‏‬




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


                       Similar findings by ...
                       Christian and Heinrich (1998)‫‏‬
                       Christian (2002a)‫‏‬
                       Christian (2002b)‫‏‬




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


                       Similar findings by ...
                       Christian and Heinrich (1998)‫‏‬
                       Christian (2002a)‫‏‬
                       Christian (2002b)‫‏‬
                       Christian (2004)‫‏‬




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


                       Similar findings by ...
                       Christian and Heinrich (1998)‫‏‬
                       Christian (2002a)‫‏‬
                       Christian (2002b)‫‏‬
                       Christian (2004)‫‏‬




Christian and Dzemski (2007) – stress patterns
         The state of the art
Low necks popularised by the BBC (and AMNH)‫‏‬
         The state of the art
Low necks popularised by the BBC (and AMNH)‫‏‬
But
      But
What do extant animals do?
 Habitual posture of extant animals
Vidal et al (1986)‫‏‬on‫“‏‬unrestrained‫‏‬awake‫‏‬animals”




Cat, sitting and standing (Vidal et al. 1986: fig. 3)‫‏‬
 Habitual posture of extant animals
Vidal et al (1986)‫‏‬on‫“‏‬unrestrained‫‏‬awake‫‏‬animals”




   But what about nice, cuddly bunny-rabbits?
  Habitual posture of extant animals
Nice, cuddly bunny-rabbits have vertical necks, too.




Rabbit in semi-alert posture (Vidal et al. 1986: fig. 4)‫‏‬
Habitual posture of extant animals
        And so do rats and guinea pigs




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




Rat and guinea pig (Vidal et al. 1986: fig. 5B-C)‫‏‬
Habitual posture of extant animals
     What about the humble chicken?
Habitual posture of extant animals
 Chicken necks habitually bend backwards!




                           (Vidal et al. 1986: fig. 7)‫‏‬
Vidal et al.'s (1986) key findings


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


            Habitual posture is not ONP

   Cervicodorsal joint is maximally extended
    Vidal et al.'s (1986) key findings


               Habitual posture is not ONP

   Cervicodorsal joint is maximally extended

       Craniocervical joint is maximally flexed
    Vidal et al.'s (1986) key findings


               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


                   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
Cold-blooded/sprawling amniotes




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




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




    Turtle (Landberg et al. 2003:fig. 8)‫‏‬
   Non-amniote tetrapods




Salamander (Simons et al. 2000:fig. 4)‫‏‬
Neck posture
mapped onto
cladogram
Neck posture
mapped onto
cladogram
Neck posture
mapped onto
cladogram



Upright posture
Neck posture
mapped onto
cladogram



Upright posture

Homeothermy
Diplodocus carnegii
(based on Hatcher 1901)‫‏‬




                           (Skull orientation based
                             on occipital condyle)‫‏‬
      Dicraeosaurus deathmatch!




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




Janensch (1936: plate 16) vs. Wilson (2002: fig. 1)‫‏‬
Also‫‏...‏‬what‫‏‬does‫“‏‬neutral”‫‏‬actually‫‏‬mean?



   Modified from Stevens and Parrish (2005b: fig. 6.8)‫‏‬
                     Neutral pose
Also‫‏...‏‬what‫‏‬does‫“‏‬neutral”‫‏‬actually‫‏‬mean?



   Modified from Stevens and Parrish (2005b: fig. 6.8)‫‏‬
                Ventrally deflected by 8°
Also‫‏...‏‬what‫‏‬does‫“‏‬neutral”‫‏‬actually‫‏‬mean?



   Modified from Stevens and Parrish (2005b: fig. 6.8)‫‏‬
                Dorsally deflected by 8°
Thanks for listening                  Your neck
                                      (all seven vertebrae)‫‏‬



                                      Sauroposeidon C8
                                            (one vertebra)‫‏‬




Visit our blog: Sauropod Vertebra Picture of the Week
              http://svpow.wordpress.com/

				
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