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Re: birds/dino-birds with teeth




On Sun, 5 May 2002, Graydon wrote:

> If you're a relatively small animal under selection pressure to
> grow to mature size rapidly, any metabolic cost related to the growth
> process which can be got rid of is likely a net win.
> Toothlessness in birds probably goes with rapid hatchling growth.

In support of this is the early craniofacial vs. brain development in
marsupials.  Relative to placentals, the development of the mouth etc.,
for early suckling postpones brain development.  Selection pressure has
apparently imposed this slow brain development cost--the point being that
rapid elaboration of craniofacial structures does have a penalty and is
expensive.