Fossil Dyna Pachycephalo was released in the OCG a little over two months after it's debut in the anime (Anime debut was June 6, 2007. OCG release was August 24, 2007) and Jim also used an Alligator deck in the manga, not Fossil.
Yep at 47:38 Gunvoltix in chat is correct. I was totally playing Jim's deck. Fossils are a ton of fun! Very underrated deck imo. I'm still experimenting and doing some things to it, but so far, I've enjoyed playing it a lot more than I thought I would.