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Re: Diplodocus: Return to the Swamps????



Newspapers in the US used to run ads asking "Why do the heathen rage?" Having 
long since given up on any answer to that opaque question, I ask instead, "Why 
does the text get chopped?" 

Chopped text -- "I mention this because I wished to confirm my deduction that 
Janensch used the 'mired sauropod' to support his contention that sauropods 
were aquatic." 

--- On Mon, 12/21/09, don ohmes <d_ohmes@yahoo.com> wrote:

> From: don ohmes <d_ohmes@yahoo.com>
> Subject: Re: Diplodocus: Return to the Swamps????
> To: dinosaur@usc.edu
> Date: Monday, December 21, 2009, 4:07 PM
> Fowler/Williams/Chure -- 'vertical
> limb elements'.
> 
> Basic assumption -- the "vertical limb elements" found at
> various locations do indeed represent sauropods that died
> with their legs embedded in soft sediments. 
> 
> Conclusion -- most concisely, this in fact proves that
> sauropods definitely at least on occasion ventured into
> areas of soft footing. At least occasionally they died in
> that position.
> 
> Further -- There are various scenarios that can be
> logically associated with limb elements found in "mired
> position". 
> 
> The primary case is, "Death occurred as a direct result of
> being immobilized by soft sediments." This case, even if
> proven in a particular instance, does not serve to reject
> speculation that sauropods utilized areas of soft sediments
> and overlying water as areas of refuge from predation by
> theropods, and/or sources of elevated browse inaccessible to
> other herbivores. In other words, the proposition: "This
> sauropod mired and died with it's limbs embedded in soft
> sediments, therefore all sauropods that had their limbs
> embedded in soft sediments must have mired and died." 
> is fallacious on it's face. Or re-stated yet again,
> 'utilization of "swamp" by sauropods' as a viable concept
> does not hinge on proving they were 'impossible to mire', or
> even 'impossible to eat'.
> 
> Given that: a) over time, many sauropods must have been
> forced by circumstance into soft sediments, whatever their
abilities or behavioral
> characteristics were, and b) there is a relatively high
> probability of preservation of a mired carcass, it would be
> expected that a significant percentage of sauropod fossils
> would be in the 'mired position', were they highly
> vulnerable to death by miring, or even the occurrence of
> death while in 'mired postion'.*  
> 
> I had hoped to get to the library and do some reading, but
> weather, other activities and "Christmas library hours"
> intervened. I mention this because I wished to confirm my
> deduction that Janensch used the 'mired sauropod' to support
> his contention that sauropo
> I was unable to do so, yet. Also, trackways apparently
> support the idea that sauropods traveled in groups, in
> ground soft enough to preserve tracks. Were they highly
> vulnerable to miring, one might expect to find evidence of
> miring episodes that involved multiple individuals. I think
> there is at least one candidate locality, but am not sure.
> Another path left untraveled, but the library will re-open
> sometime, and I might make it there when it does, so maybe
> later for that.
> 
> *I assume that such 'vertical' finds are _relatively_ rare,
> but that is only an assumption on my part. Perhaps someone
> already knowledgeable could comment on that assumption? Even
> a rough estimate of 'mired' vs 'unmired' specimens is likely
> more than I can take on.
> 
> --- On Mon, 12/14/09, Denver Fowler <df9465@yahoo.co.uk>
> wrote:
> 
> > From: Denver Fowler <df9465@yahoo.co.uk>
> > Subject: Re: Diplodocus: Return to the Swamps????
> > To: dinosaur@usc.edu
> > Date: Monday, December 14, 2009, 1:02 AM
> > Sauropod remains consistent with
> > miring events are known from a number of localities
> > including:
> > 
> > the mother's day site (Morrison Fm, Montana),
> although
> > newer interpretations disagree (e.g. Myers &
> Storrs,
> > 2007)
> > 
> > 1992 'Brachiosaur', Wessex Fm, UK
> > unpublished 'diplodocoid' Wessex Fm, UK
> > I recall that at least one limb was found upright at
> the
> > Howe
 abstracts at SVP & GSA 2001:
> Alamosaurus
> > material from Big Bend, TX
> > 
> >  ----------------------------------
> > Denver Fowler
> > df9465@yahoo.co..uk
> > http://www.denverfowler.com
> > -----------------------------------
> > 
> > 
> > 
> > ----- Original Message ----
> > From: Tim Williams <tijawi@yahoo.com>
> > To: dinosaur@usc.edu
> > Cc: tijawi@yahoo.com
> > Sent: Sun, 13 December, 2009 21:52:19
> > Subject: Re: Diplodocus: Return to the Swamps????
> > 
> > 
> > Although I don't have a dog in this race, this thread
> > reminds me of the taphonomy one of the larger
> specimens of
> > the sauropod _Giraffatitan brancai_.  The humerus and
> a
> > tibia of this specimen (SII) were preserved in an
> upright
> > positi
> 914) to adduce that the
> > individual had been mired in soft mud before burial.
> > 
> > 
> > This was at "Tendaguru Site S", as discussed by
> Heinrich
> > (1999) in his summary of the taphonomy of the
> Tendaguru
> > dinosaur locality.
> > 
> > 
> > Cheers
> > 
> > Tim
> > 
> > 
> > --- On Sun, 12/13/09, don ohmes <d_ohmes@yahoo.com>
> > wrote:
> > 
> > > From: don ohmes <d_ohmes@yahoo.com>
> > > Subject: Re: Diplodocus: Return to the
> Swamps????
> > > To: dinosaur@usc.edu
> > > Date: Sunday, December 13, 2009, 10:35 PM
> > > --- On Mon, 12/14/09, Jonas
> > > Weselake-George <Paleo@ncf.ca>
> > > wrote:
> > > 
> > > > From: Jonas Weselake-George <Paleo@ncf.ca>
> > > > Subject: Re: Diplodocus: Return to the
> > Swamps????
> > > > To: dannj@alphalink.com.au,
> > > dinosaur@usc.edu
> > > > Date: Monday, December 14, 2009, 1:13 AM
> > > > 
> > > > Dann Pigdon <dannj@alphalink.com.au>
> > > > wrote:
> > > > "It goes in splayed with plenty of
> resistance
> > > (limiting the
> > > > depth of penetration), but is drawn out
> with
> > converged
> > > toes
> > > > that offer far less resistance. Sauropods,
> on
> > the
> > > other
> > > > hand, would have had to fight each step to
> extra
> > 
> > > foot
> > > > from deep mud. That's bound to tire a large
> > animal out
> > > after
> > > > a 
What about taking into account mass (and
> muscle
> > mass)
> > > vs.
> > > > limb surface area? It would seem to me that
> a
> > fifteen
> > > ton
> > > > sauropod would experience less relative
> suction
> > than a
> > > one
> > > > ton theropod. What do you think? 
> > > 
> > > Exactly. Re is critical (or perhaps some related
> but
> > more
> > > situation-appropriate and specialized metric).
> Mud is
> > > essentially less dense/viscous for larger
> animals...
> > >  
> > > > Additionally, the sauropod would tend to
> punch
> > through
> > > to
> > > > the substrate more easily and would also
> have
> > four
> > > limbs for
> > > > balance. I'm not arguing that it'd be easy,
> but
> > a
> > > large
> > > > sauropod might have an advantage in moving
> > through a
> > > swamp
> > > > (not that it is very likely a theropod one
> > fifteenth
> > > its
> > > > weight would have a motivation to foll
> at repeatedly sheared mud tends to
> > liquify.
> > > In other words, if you have the power to shear it
> in
> > the
> > > first place, it becomes easier w/ each shearing.
> And
> > less
> > > supportive to any splay-footed interloper. 
> > >  
> > > > A more likely situation would be sauropods
> > taking
> > > advantage
> > > > of the mud to mate (after all I saw a paper
> > suggesting
> > > that
> > > > an early cretaceous ornithopod population
> was
> > using
> > > swamps
> > > > for shelter during the breeding season).
> > > 
> > > What is unlikely about a theropod-free zone?
> > > 
> > > Anyhow, to bed for me...
> > > 
> > 
> > 
> >       
> > 
> > 
>