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RE: Theory Sez Flight Evolution Linked To Parental Care






From: "Williams, Tim" <TiJaWi@agron.iastate.edu>
Reply-To: TiJaWi@agron.iastate.edu
To: "'Dino Guy and Computer Gal '" <gbabcock@best.com>
CC: "'dinosaur@usc.edu'" <dinosaur@usc.edu>
Subject: RE: Theory Sez Flight Evolution Linked To Parental Care
Date: Wed, 30 Jan 2002 14:47:13 -0600


Ralph W. Miller wrote:

>Yes, I've wondered how much weight savings one derives from replacing
>teeth with a beak, and loading your gizzard with grit or stones to >process
food!


One theory (as I understand it) is that a beak (cornified
rhamphotheca)provides a better cutting edge than jaws packed with teeth, and
compensates for the lack of clawed forelimbs in birds.


Do you mean for prey/object manipulation? If so, why better than teeth?

I also thought that most Mesozoic birds were toothed; toothless birds
(confuciusornithids, gobipterygids, neornithine) were in the minority.
Oviraptorosaurs, segnosaurs, ornithomimosaurs and ornithischians had
toothless beaks as well, often in combination with teeth.



Tim




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