A new approach to determining

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A new approach to determining the habitual neck p
osture of sauropods based on the behaviour of ext
ant animals Michael P. Taylor1 Mathew J. Wed
el2 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 P
odiatric Medicine, Western University of
Health Sciences, 309 E. Second Street, Pomona,
California 91766-1854, USA.
2
Historical background
The earliest sauropod reconstructions had
horizontal necks
Camarasaurus (Ryder 1877)? Reprinted by Osborn an
d 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)?
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Historical background
Later sauropod reconstructions had raised necks
Brachiosaurus brancai (Janensch 1950b plate
VIII)?
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Historical background
Later sauropod reconstructions had raised necks
Brachiosaurus brancai (Paul 1988fig. 1)?
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Historical background
Later sauropod reconstructions had raised necks
?!
Brachiosaurus brancai (Paul 1988fig. 1)?
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Historical background
Later sauropod reconstructions had raised necks
Brontosaurus (Zallinger's 1947 mural at YPM)?
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Recent work has reverted to horizontal
Necks considered low and inflexible
Leicester City Museum Cetiosaurus oxoniensis
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Recent work
Necks considered low and inflexible
Martin (1987 fig. 2)?
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Recent work
Osteological neutral pose (ONP)?
Stevens and Parrish (2005b fig. 10.3A) same
specimen
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Recent work
Osteological neutral pose (ONP)?
Stevens and Parrish (2005a fig. 6.5B)
Diplodocus carnegii
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Recent work
(Giraffes are different ONP gives rise to an
erect neck)?
Stevens and Parrish (2005a fig. 6.2) Giraffe
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Recent work
Sauropod necks considered low and inflexible
Stevens and Parrish (2005a fig. 6.14)
Diplodocus carnegii

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Recent work
Necks considered low and inflexible
Stevens and Parrish (1999 fig. 2B) Diplodocus
carnegii
DinoMorph
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Recent work
Necks considered low and inflexible
Stevens and Parrish (1999 798, 800)?
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Recent work
Necks considered low and inflexible
Stevens and Parrish (1999 798, 800)?
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Recent work
Necks considered low and inflexible
Stevens and Parrish (1999 798, 800)?
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Recent work
Necks considered low and inflexible
Claim ONP is sub-horizontal in all sauropods
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Recent work
Necks considered low and inflexible
Claim ONP is sub-horizontal in all sauropods
Claim ONP is the habitual posture
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Recent work
Neck held high
Christian and Dzemski (2007) stress patterns
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Recent work
Neck held high
Similar findings by ...
Christian and Dzemski (2007) stress patterns
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Recent work
Neck held high
Similar findings by ... Christian and Heinrich (1
998)?

Christian and Dzemski (2007) stress patterns
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Recent work
Neck held high
Similar findings by ... Christian and Heinrich (1
998)?
Christian (2002a)?
Christian and Dzemski (2007) stress patterns
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Recent work
Neck held high
Similar findings by ... Christian and Heinrich (1
998)?
Christian (2002a)? Christian (2002b)?
Christian and Dzemski (2007) stress patterns
27
Recent work
Neck held high
Similar findings by ... Christian and Heinrich (1
998)? Christian (2002a)? Christian (2002b)? Chr
istian (2004)?
Christian and Dzemski (2007) stress patterns
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Recent work
Neck held high
Similar findings by ... Christian and Heinrich (1
998)? Christian (2002a)? Christian (2002b)? Chr
istian (2004)?
One-man crusade?
One-man crusade?
Christian and Dzemski (2007) stress patterns
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The state of the art
Low necks popularised by the BBC (and AMNH)?
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The state of the art
Low necks popularised by the BBC (and AMNH)?
All based on ONP
All based on ONP
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But
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But
What do extant animals do?
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Habitual posture of extant animals
Vidal et al (1986) on unrestrained awake animals
Cat, sitting and standing (Vidal et al. 1986
fig. 3)?
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Habitual posture of extant animals
Vidal et al (1986) on unrestrained awake animals
But what about nice, cuddly bunny-rabbits?
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Habitual posture of extant animals
Nice, cuddly bunny-rabbits have vertical necks,
too.
Rabbit in semi-alert posture (Vidal et al. 1986
fig. 4)?
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Habitual posture of extant animals
And so do rats and guinea pigs
Rat and guinea pig (Vidal et al. 1986 fig. 5B-C)?
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Habitual posture of extant animals
And so do rats and guinea pigs
Is it just mammals?
Is it just mammals?
Rat and guinea pig (Vidal et al. 1986 fig. 5B-C)?
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Habitual posture of extant animals
What about the humble chicken?
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Habitual posture of extant animals
Chicken necks habitually bend backwards!
(Vidal et al. 1986 fig. 7)?
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Vidal et al.'s (1986) key findings

• Habitual posture is not ONP

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Vidal et al.'s (1986) key findings

• Habitual posture is not ONP
• Cervicodorsal joint is maximally extended

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Vidal et al.'s (1986) key findings

• Habitual posture is not ONP
• Cervicodorsal joint is maximally extended
• Craniocervical joint is maximally flexed

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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

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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

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Cold-blooded/sprawling amniotes
Alligator (Claessens, unpublished photo)?
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Cold-blooded/sprawling amniotes
Unspecified lizard (Vidal et al. 1986 fig. 8A)?
Varanid lizard (Brainerd and Owekowicz 2006 fig.
4)?
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Cold-blooded/sprawling amniotes
Turtle (Landberg et al. 2003fig. 8)?
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Non-amniote tetrapods
Salamander (Simons et al. 2000fig. 4)?
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Neck posture mapped onto cladogram
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Neck posture mapped onto cladogram
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Neck posture mapped onto cladogram
Upright posture
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Neck posture mapped onto cladogram
Upright posture Homeothermy
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Diplodocus carnegii (based on Hatcher 1901)?
(Skull orientation based on occipital condyle)?
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Dicraeosaurus deathmatch!
Janensch (1936 plate 16) vs. Wilson (2002 fig.
1)?
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Dicraeosaurus deathmatch!
Janensch (1936 plate 16) vs. Wilson (2002 fig.
1)?
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Also ... what does neutral actually mean?
Modified from Stevens and Parrish (2005b fig.
6.8)?
Neutral pose
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Also ... what does neutral actually mean?
Modified from Stevens and Parrish (2005b fig.
6.8)?
Ventrally deflected by 8
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Also ... what does neutral actually mean?
Modified from Stevens and Parrish (2005b fig.
6.8)?
Dorsally deflected by 8
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Thanks for listening
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