[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Parrish's neck work ...



Ronald Orenstein wrote:
> I have always assumed that these teeth would be quite useful in stripping
> leaves from branches - you can get a similar effect by drawing a leafy
> branch through a garden rake (or, better yet, use two garden rakes in
> opposition).  One might ask why modern browsers aren't built that way, but
> of course these are mammals, which (a) rely on teeth rather than gizzard
> stones to crush and masticate plant material and (b) have quite different
> (I assume based on birds) tongue anatomies.  I would wonder if any dinosaur
> could have been expected to evolve a muscular, mobile tongue such as the
> leaf-stripping apparatus found in giraffes.

you might also mention the extremely flexible split lips of giraffes,
llamas, camels, and tree-browsing goats and antelopes in addition to the
prehensile tongues.

> Which raises the issue - how do you knock down a tree?  Surely the easiest
> way for an animal like this is to rear, plant your front limbs against the
> trunk and bear forward.  Seen this way, an unsteady rearing posture might
> be no problem if all that was required was to get into position before
> yelling the sauropod equivalent of "timber!".

If you watch documentaries of elephants eating saplings they:
-push trees over with their heads
-shove trees over with their shoulders
-back into trees and sit on them
-stomping on them with a single foot
-push them over with both feet
-have two or more individuals push on the same tree in opposite
directions
-wedging the sapling between trunk and tusks and pulling it out

Excepting the last I could see sauropods using any of these methods to
knock down a tree, and only one actually involves rearing.

> One anatomical feature you did not mention: the claw on digit I of the
> manus, the only claw sauropods retain (and I gather even that is missing in
> some Cretaceous forms).  It would seem reasonable to assume that this claw,
> when present, had some function, perhaps defensive - but if so it could
> only have been useful if it could be brought into play.

It was already mentioned in this thread that the flexibility of the neck
allows the head to interact with the feet easily.  Perhaps the tusk
wedging property of elephants is not so far-fetched.

-Betty Cunningham

-- 
Flying Goat Graphics
http://www.flyinggoat.com
(Society of Vertebrate Paleontology member)
-------------------------------------------<,D,><