This LiveScience.com article looks at the WORLD'S OLDEST KNOWN SPIDER WEB. It's about 140 million years old, and of course it was preserved in amber.
That amber (tree sap) is amazing stuff. I don't know why Ted Williams didn't just have his head coated in amber instead of going the cryogenic freezing method. It would be a lot cheaper than what those cryo companies charge, and if future scientists can revive a severed head, they can surely clean off the amber (lemon-powered "Amber Away").