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Alvarezsaur spurs (was Re: dino-lice)
On Wed, Apr 20th, 2011 at 12:17 PM, Tim Williams <firstname.lastname@example.org> wrote:
> I have no doubt that alvarezsaurids used their truncated, monodactyl
> forelimbs for *something* - and as with the tyrannosaurids, it was
> probably a trophic function. But unlike David M., I associate
> forelimb truncation in alvarezsaurids with a lack of day-to-day usage,
> rather than being an optimization for digging.
The problem I have with envisaging them as specialised diggers is that anything
within reach of
those stumpy forelimbs would seem to have been also out of sight. Not being
able to see what you
are digging into would appear to be a major disadvantage. Having such long legs
would also seem
to require them to be in some sort of prone position in order to dig.
Perhaps they were useful for scraping out nest hollows while the animal was
lying prone, done
mostly by feel rather than sight. Otherwise they'd have been quite inconvenient
Neither would they seem to have been much good for defense, since any predator
close enough to
be in range of the forelimbs had probably already bitten into the head or neck.
They do remind me somewhat of platypus spurs though, which are used almost
intraspecific combat (platypus don't produce much, if any, venom outside of the
so the spurs aren't much use as a general year-round defense against predators).
Spatial Data Analyst Australian Dinosaurs
Melbourne, Australia http://home.alphalink.com.au/~dannj