Where did oil come from? We will cover that subject much more thoroughly in the next section, but for now, we need to take a quick look at where it did not come from.
Many people, think that the oil we use today came from dinosaurs of long ago. In fact, that is what was taught in some schools for a long time. People were taught that dinosaurs, either through natural death or some calamity --- like an earthquake or landslide --- were buried and eventually turned into oil.
There is no doubt that some dinosaurs probably became the source of some oil -- but actually very little of it. One of the reasons is simply this: when a dinosaur died, as land dwelling animal, it was exposed to an oxygen rich environment which would lead to rapid decay and prevent the processes necessary to convert something to oil from taking place. Not only that, but dead dinosaurs were food for many scavengers -- again preventing the necessary natural processes from converting the animal to oil.
One might say, but wait, many of them were preserved enough to be fossilized and for that to happen, they had to be in a protected (no free air, no scavengers) environment. That is partially true. We have found fossilized bones of dinosaurs with the teeth marks of either an attacker or a scavenger still on them. However, there are actually very few fossilized remains of land animals when compared to the number of fossilized marine animals. This is evident to all. Next time you take a trip and you travel roads that have been cut through hilly or mountainous areas, take a look and see if you can see the layers of sedimentation. If you can, stop and dig around in the layers with your fingers and you will find buckets of fossilized marine life. In contrast, many paleontologists spend a lifetime looking for one good, complete or semi-complete, dinosaur skeleton. There just are not that many of them and certainly not enough of them to account for the huge deposits of oil we find through out the world.
So where did the oil come from? Stay tuned, you will be surprised!!