re: Tanystropheus neck posture

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

At 07.44 24/10/02 -0500, you wrote:
> Maybe Tanystropheus wasn't marine.
>
> I just took a look at Wild 1973 and note that in exemplar q,

err.. in Wild 1973 exemplar q is an isolated skull and neck, thus you 
probably refer to another specimen, but which one? exemplar m looks like 
having a crack just there, exemplar k show anterior dorsals but to my eyes 
the angle is between the last cervical and the first dorsal, exemplar a, 
the one figured also in the site shows a some angle between anterior dorsals.

>   To my eye there is no neck contraction, but rather it
> appears to have a camarasaur-like setup.
I can check it on the cast of specimen a...

> Just a wild hypothesis, but what if Tanystropheus fed on arboreal
> diapsids, like longisquamids and basal pterosaurs, by standing at the
> base of trees and searching the boughs for prey?  The clincher is the
> giant penile bones would make great bases for a tripodal posture.
>
> Mmm... the Gerenuk (if I remember the correct name) is an antelope with a 
> long neck that adopts bipedal stance to browse high foliage, keeping 
> steady by grappling trees with forelimbs. The posture is a bit awkward but 
> apparently it works. However the main difference is that foliage doesn't 
> rush away when the head come close it is much simpler to pick up also in a 
> static position. a small swift animal is much harder to be catched in that 
> way, I suspect.   Foliage is abundant and you have not to move from a tree 
> to another too often, thus this feeding strategy is rewarding for the 
> antelope. A predator should move much more frequently, especially if 
> catching a small prey it puts all the neighbours in alarm and they flee 
> away. And foliage, small branches etc. may be a serious obstacle to catch 
> those preys. Much better to be small or sneaky for this task.
And don't forget, apparently the clincher or whatever they are, are present 
only in half of larger known specimens...

All the best,

                                Silvio






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Silvio Renesto

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