It's not fossil fuel. It is carbon based fuel.
Well, there are heck of a lot of near-surface microfossils in any given handful of crude. I think the standard explanation of how they got there is more satisfactory than to say they migrated to it.
From wikipedia:
"Carbon-based fuel is any fuel whose energy derives principally from the oxidation or burning of carbon. Carbon-based fuels are of two main kinds, biofuels and fossil fuels."
Is the wiki wrong? Thanks in advance.