You know what I like? People not multiposting, and editing their original post if they want to add something, and not trying to increase their post count.
You know what else is random, and belongs here? The fact that there were far more dinosaurs than we expected. Trilobites are a good example. The chances of something being fossilized are incredibly low. The chances that we will find one is also incredibly low. Trilobites are some of the most common fossils to find, and generally cost around 3-8-15 dollars. In the fossil economy, this is an incredibly low price. This can only be done, due to their abundance. This means, if we recognize that fossil forming is very rare, that there were not millions, there were likely billions, perhaps trillions, of these things over millions of years. Extrapolating this data towards dinosaurs, it is very likely that there were far more than expected. If you ever time travel, perhaps avoid anything before 64 million years ago. You don't want to be overcrowded by all those dinosaurs.