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Re: Great in the air, not so good underwater

----- Original Message ----- From: "Michael Habib" <mhabib5@jhmi.edu>
To: <dinosaur@usc.edu>
Sent: Friday, December 08, 2006 6:50 PM
Subject: Re: Great in the air, not so good underwater

Just the same, the running launch system has particular constraints and benefits.

I agree.

Constraint pretty clearly prohibits the forelimb-assisted launch cycle in birds, and thus I doubt they'll ever produce volant members as large as pterosaurs.

Yes. I suspect that there may be constraints due to feather morphology as well, but that's just a hunch.

Stabilizing selection is probably hard at work, too, though: despite denying some helpful launch modes, avian bipedality has some great advantages. In fact, being bipedal gives birds access to some launch solutions denied to pterosaurs and bats; the ones I have in mind work best at small to medium body sizes.

I agree.

Still, I'll bet nothing beat seeing a Quetzalcoatlus catapault off the ground...makes me sad that they're gone.

Or Hatzegopteryx, or Arambourgiana (sp??). I tend to think of them as if they were still alive, and it jolts sometimes when I'm forced to think about their demise. A cautionary tale for developing methods of meteor control during the next few centuries.

All the best,