@PetraPhoenix I think that petrol is mostly made up of *plants* that coexisted with dinosaurs, so the problem isn't really relevant.
although, some plants do get their nutrients from decomposed animal carcasses, so some dead animals are still involved?
I guess most of those animals died of natural causes, but then some may have also been killed by predators, and I don't know how that part counts
am I overthinking a question posed by an 8 year child?