Re: Death poses (mid-length message)

[Silvio Renesto <renesto@mailserver.unimi.it>]

At 18.38 04/06/02 -0400, you wrote:
> You win the argument. As far as I know, the going consensus is that after 
> death, but before being completely buried (and ultimately fossilized), the 
> ligaments and tendons in the animal's neck dry out and contract, pulling 
> the head back over the body. This can be seen in many dinosaur skeletons, 
> aside from those from Solnhofen, and is not exclusive to theropods.

Indeed many, many long necked animals show this, and drying plays a major 
role in most cases, needless to say.
However, maybe that not always it is needed an essication to have ligament 
contraction (Solnhofen pterosaurs weren't all washed into the basin after 
death & desiccation, nevertheless they frequently show a bent neck). It is 
possible that  anatomy and aquatic microenvironment (salinity included) 
play some role:
Just an example: in Italian and Swiss Middle Triassic sites, we have mainly 
two kinds of long necked reptiles, the "nothosaurs" and the 
prolacertiforms. Even in the same localities  you always  find  the 
prolacertiforms with  the neck  dramatically bent back (in the genus 
Tanystropheus there is also a recurrent  complex pattern of disarticulation 
between head +ribs on one hand and cervicals on the other, that IMHO should 
be worth of deeper study)  while the "nothosaurs" always show a much more 
"loose", straight or slightly undulate, pose.
This is undoubtedly related at a great extent to the completely different 
structure of the cervicals, and suggests in the same time that post mortem 
contraction of ligaments may occur also in water. in fact, it is doubtful 
that Tanystropheus carcasses were dryed out before burial if we 
accept  current view that this reptile was mainly aquatic.
> For what it is worth,


                                                Silvio


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"The Wise Man is like a bamboo tree;
                simple, upright, and useful, but hollow inside"

                                                Lao Tzu

Silvio Renesto

Dipartimento di Scienze della Terra
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