RE: Theory Sez Flight Evolution Linked To Parental Care

["Williams, Tim" <TiJaWi@agron.iastate.edu>]

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.

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