Achilles is 100% correct.
https://www.nasa.gov/mission_pages/cassini/media/cassini-20080213.html
EDIT: Oops... didn't see there was a page two here.
I didn't think he was incorrect. In fact, I agree with him. My query was how did he know, ""Fossil" fuels do not come from fossils"? Because clearly they do. The other part of the question was relating to how does he know that there have never been dinosaurs on any of Juno's moons? We got billions of years of history to look back to on these planets and moons, and well, we just can't rightly go there and be all paleontological and shit, now can we?