Here is a guy auctioning off some pretty old (literal) shit
http://cgi.ebay.com/COLORFUL-SPECIMEN-OF-COPROLITE-DINO-DUNG-ROCK-FOSSIL_W0QQitemZ260205679890QQihZ016QQcategoryZ15915QQssPageNa
I guess its has to be a couple hundred years older than Jesus :< {