Re: Pteraichnus prints

[ornstn@hookup.net (Ronald Orenstein)]

>(You've heard that pterosaurs were batlike and bird like, but now consider
>that they may have been like Australian frillnecks, basking on trees in the
>early dawn, walking bipedally on the ground for a short period (...yes, I
>said walking), then retreating up the tree to the shade for the majority of
>the day to avoid overheating.  And that's just the start. [Shine and Lambeck
>1989])

If what you are saying is that pterosaurs may have been able to move both
bipedally and quadrupedally, perhaps so (I have not studied their anatomy);
but although pterosaurs are remarkably consistent in many postcranial
features I find it hard to believe that (say) Anurognathus and
Quetzalcoatlus behaved in the same fashion (not to mention Pterodaustro).

But I am not entirely convinced by your frilled-lizard analogy.  Lizards
like this use bipedality for high-speed action, usually to escape predators.
But pterosaurs had no need to run from predators - they could fly (assuming
relatively easy takeoff), so why would they need high-speed ground
locomotion?  I assume no one is suggesting the existence of courser-like,
primarliy terrestrial bipedal pterosaurs.  If pterosaurs assumed bipedal
postures perhaps this had more to do (pure lay guesswork here) with either
display or assuming positions for takeoff and landing - both of which may
have had more to do with standing bipedally than running.

And I would still like to know how widely-accepted is the view that the
so-called "pterosaur" trackways were indeed made by pterosaurs.
--
Ronald I. Orenstein                           Phone: (905) 820-7886 (home)
International Wildlife Coalition              Fax/Modem: (905) 569-0116 (home)
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