“That deadly beak may be a surprise to many people and has long posed a puzzle for scientists. They wonder how a creature without any bones can operate it without hurting itself.

The beak, made of hard chitin and other materials, changes density gradually from the hard tip to a softer, more flexible base where it attaches to the muscle around the squid’s mouth, the researchers found.

That means the tough beak can chomp away at fish for dinner, but the hard material doesn’t press or rub directly against the squid’s softer tissues

The razor-sharp beaks that giant squids use to attack whales – and maybe even Captain Nemo’s submarine – might one day lead to improved artificial limbs for people. “

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http://www.signonsandiego.com/uniontrib/20080328/news_1n28squid.html