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Re: Sauropods Then and Now



> > Older books on sauropod behavior treated them as
> slow moving
> > swamp-dwellers whose diet was aquatic vegetation,
> but this changed
> > about when?  

Not really. The original victorian-age consensus was
that sauropods were terrestrial (they did leave an
awful lot of footprints everywhere you know), then
around the late 1920's and early 30's there was this
drift towards dinosaurs being interpreted as slow dumb
lizards (founded more on opinion than science):
Sauropods got dumped in lakes, t.rex lay down on the
ground (unable to get up 'cause of his cruddy little
arms), Birds decided they wanted nothing to do with
dinosaurs and changed their surnames to -suchus, and
everyone went off to study mammals instead. This came
to a halt with the pioneering work (and rediscovery)
of Ostrom & McIntosh in the late 60's, and we haven't
looked back since.

(if you want a graphic illustration of this, contrast
how charles knight's paintings change from the
exciting depictions of the turn of the century,
through the 1910's, then how he sinks into the dull
plodders at the end of his life around the 30's and
40's, alhtough there was an aquatic apatosaurus
painted in 1897)

It really serves a good lesson, repeated often by the
likes of Bakker etc, that the old boys really knew
what they were doing, and I don't just mean the
academics. If you read through Sternberg's books, you
see he had some insights into palaeontology that would
not be revisited for nearly a century. In particular,
he objected to the restoration of hadrosaurs in an
upright posture. Every specimen he had found, and
adoringly prepared, had a long straight backbone,
supported relatively rigid by tendons. He suggested
the posture we accept today: that of the backbone
parallel to the ground. You see similar insights in
some of the notes from Mary Anning, although sadly she
didn't write much. 


I vaguely recall pictures of
> sauropods (brachiosaurs?)
> > feeding from the tree-tops from about the mid-70s.
>  Is this the
> > right time frame?  And I recall the motivation for
> this new view
> > being the discovery of remains from upland
> environments.  Or not?
> 

This is probably associated with bakker's work 'the
ecology of the brontosaurs': that neck length dictated
different feeding envelopes that segrated sauropod
feeding niches. the recent work of Parrish & Stevens
adds further complexity to this.




> I can't help you much with timing, but one important
> paper is Coombes
> 1975, which made a compelling biomechanical argument
> for the
> terrestriality of sauropods, based on the deep and
> (relatively) narrow
> torso.  Is is certainly true that many sauropod
> specimens have been
> found in geological settings not consistent with
> swampland: for
> example, Dodson et al. (1980) concluded that the
> sauropod-rich
> Morrison Formation was seasonally dry.  Alexander
> (1989) pointed out
> that the feet of sauropods are the most compact of
> any terrestrial
> animals, so that they would have become mired in
> swamps if they tried
> to live there.  The taphonomy of the _Brachiosaurus
> brancai_ holotype
> HMN SII confirms this, as it was found with the
> limbs mired in an
> upright position (Russell et al. 1980).  Also the
> pneumatisation of
> the skeleton (see e.g. Wedel 2003a, 2003b) is best
> interpreted as a
> lightening adaptation for terrestrial life.
> 
> > More recently, however, there has been much talk
> on this list of
> > certain sauropods (diplodocids? or others as
> well?) perhaps being
> > designed for a semi-aquatic environment after all.
> 
> I've never heard of this.  Reference, please!
> 

You might be referring to Don Henderson's work on
floating sauropods. Certainly sauropods got about a
bit: Alamosaurus had to swim a little to make it
across from South America (assuming it didn't come
from asia / hidden endemic), but swimming ability
doesn't mean aquatic. Elephants are great swimmers.

But let's not get started on Alamosaurus till I
receive my copy of JVP, or SVP put it online in pdf
form. Did anyone see the ash dates for the Javelina? I
would be interested to see how that is discussed.

Denver.


>  _/|_ 
>
___________________________________________________________________
> /o ) \/  Mike Taylor  <mike@miketaylor.org.uk> 
> http://www.miketaylor.org.uk
> )_v__/\  "What is this talk of 'release'?  Klingons
> do not make software
>        'releases'.  Our software 'escapes,' leaving a
> bloody trail of
>        designers and quality assurance people in its
> wake." -- Klingon
>        Programming Mantra
> 
> 
> REFERENCES
> 
> Alexander, R. McNeill.  1989.  Dynamics of Dinosaurs
> and Other Extinct
> Giants.  Columbia University Press, New York.  167
> pp.
> 
> Coombs, W.  1975.  Sauropod Habits and Habitats. 
> Palaeogeography,
> Palaeoclimatology, Palaeoecology 17: 1-33.
> 
> Dodson, Peter, A. K. Behrensmeyer, Robert T. Bakker
> and John
> S. McIntosh.  1980.  Taphonomy and paleoecology of
> the dinosaur beds
> of the Jurassic Morrison Formation.  Paleobiology 6
> (2): 208-232.
> 
> Russell, D., P. Beland and J. S. McIntosh.  1980. 
> Paleoecology of the
> dinosaurs of Tendaguru (Tanzania).  Memoirs Societe
> Geologie Francais
> 59 (139): 169-175.
> 
> Wedel, Mathew J.  2003.  The Evolution of Vertebral
> Pneumaticity in
> Sauropod Dinosaurs.  Journal of Vertebrate
> Paleontology 23(2):344-357,
> June 2003
> 
> Wedel, Mathew J.  2003.  Vertebral pneumaticity, air
> sacs, and the
> physiology of sauropod dinosaurs.  Paleobiology,
> 29(2), 2003,
> pp. 243-255
> 
> 



        
        
                
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