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A new approach to determiningthe 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 necksLater sauropod reconstructions had raised necks
Brontosaurus (Zallinger's 1947 mural at YPM)
Recent work has reverted to horizontal
Necks considered low and inflexibleNecks considered low and inflexible
Leicester City Museum Leicester City Museum Cetiosaurus oxoniensisCetiosaurus 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 carnegiiDinoMorph
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 sauropodsClaim: ONP is the habitual posture
Recent work
Neck held high
Christian and Dzemski (2007) – stress patterns
Recent work
Neck held high
Christian and Dzemski (2007) – stress patterns
Similar findings by ...
Recent work
Neck held high
Christian and Dzemski (2007) – stress patterns
Similar findings by ...Christian and Heinrich (1998)
Recent work
Neck held high
Christian and Dzemski (2007) – stress patterns
Similar findings by ...Christian and Heinrich (1998)
Christian (2002a)
Recent work
Neck held high
Christian and Dzemski (2007) – stress patterns
Similar findings by ...Christian and Heinrich (1998)
Christian (2002a)Christian (2002b)
Recent work
Neck held high
Christian and Dzemski (2007) – stress patterns
Similar findings by ...Christian and Heinrich (1998)
Christian (2002a)Christian (2002b)
Christian (2004)
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?
One-man crusade?
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)
All based on ONP
All based on ONP
But
ButWhat do extant animals do?
Habitual posture of extant animals
Vidal et al (1986) on “unrestrained awake animals”
Cat, sitting and standing (Vidal et al. 1986: fig. 3)
Habitual posture of extant animals
Vidal et al (1986) on “unrestrained awake animals”
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)
Is it just mammals?
Is it just mammals?
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)
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
Vidal et al.'s (1986) key findings
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 posturemapped ontocladogram
Neck posturemapped ontocladogram
Neck posturemapped ontocladogram
Upright posture
Neck posturemapped ontocladogram
Upright posture
Homeothermy
Diplodocus carnegii(based on Hatcher 1901)
(Skull orientation basedon 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 ... what does “neutral” actually mean?
Modified from Stevens and Parrish (2005b: fig. 6.8)Neutral pose
Also ... what does “neutral” actually mean?
Modified from Stevens and Parrish (2005b: fig. 6.8)Ventrally deflected by 8°
Modified from Stevens and Parrish (2005b: fig. 6.8)Dorsally deflected by 8°
Also ... what does “neutral” actually mean?
Thanks for listening
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Your neck(all seven vertebrae)
Sauroposeidon C8 (one vertebra)