Re: Beaks

["Philidor" <philidor11@snet.net>]

Beaks have been described as having advantages in weight/balance, diet, and
ease of replacement.  I'd add defense:  better to stab with something sharp
than to have the musculature and take the strain necessary for a bite.
Particularly with the bone structure getting lighter for flight.
Also, a beak makes selective capture of small items easier, whether animals
or seeds.

Like feathers, though, one wonders what provided the raw material for a beak
to develop.
Is there any known appurtenance made of beak-like material?