Re: STEGOSAUR TAILS (WAS DUCKBILL NECKS)

["Peter Von Sholly" <vonrex@gte.net>]

Well, I'm not shedding any disrespect on Ken Carpenter or his
respectability but I don't know how anybody can say for sure whether any
given case of in situ arrangement is due to any degree of post-death
distortion or displacement --- or not.  Maybe it's just good old rigor
mortis at work.  I doubt that most fossils show that much beyond the
postition of the bones, and we are lucky when they're articulated at all. 
And how many in situ stegosaur tails are there to go by anyway?
As to your second point, if all dinosaur tails were pulled up all the time,
why indeed would stegosaurs not be?
But since tails can be found in many positions (as can necks, of course)
how can we be dogmatic about why a given specimen is found in a given
position.  I don't accept in situ bone articulation as definitive evidence
of how bones were held or articulated in the living animal.

So... Nyaaa.  Mature, ain't I?
PVS

"Some big hard-boiled egg gets a look at a pretty face and BANG!  He cracks
up and goes sappy."

----------
> From: Brian Franczak <franczak@ntplx.net>
> To: dinosaur@usc.edu
> Subject: Re: STEGOSAUR TAILS (WAS DUCKBILL NECKS)
> Date: Thursday, September 03, 1998 6:32 AM
> 
> Peter Von Sholly wrote:
> > 
> > Brian, as always you make good, well constucted arguments but still I
say
> > phooey on these lifted tails.  Since when are in situ fossils
necessarily
> > placed the way the animals were in life?  Let's have all dinosaurs walk
> > around with their necks pulled back over their torsos.  There are lots
of
> > in situ skeletons like that.
> 
> Not a valid argument. First, if Ken Carpenter tells me that the tail
> stood out straight from the hips of _Stegosaurus_, then I trust that
> he's capable of discerning whether it was in this position because of
> post-death distortion or not. This is not a matter of "artistic
> license", this is a determination by a respected paleontologist.  
> 
> Then, of course, there is the evidence of such ligamental contraction in
> the tails of sauropods (the juvenile _Camarasaurus_ comes to mind),
> _Struthiomimus_, _Compsognathus_, _Archaeopteryx_, and _Sinosauropteryx_
> (just to name a handful). In all these instances, the tail does *not*
> articulate straight out from the pelvis, but is pulled up in the same
> (if not quite as extreme) distorted manner as the neck and skull.
> Looking at these examples, why would stegosaur tails be straight and not
> similarly bent if that was what was happening to them?
> 
> Brian (franczak@ntplx.net)
> http://www.paleolife-art.com