Over the past couple of weeks, scientists have basically claimed that the decades old questions of what killed the dinosaurs and what led to their original rise to power have been solved, at least, superficially.
The short answer is that dinosaurs were
killed by an asteroid and
rose to power via volcanic activity.
Whenever scientists say that they are "sure" of anything, take it with a grain of salt. It's true that the major events that impacted the rise and fall of the age of dinosaurs were intense volcanism and the collision of Earth with a giant space rock, respectively, but that doesn't mean that we now know everything. If that's confusing, just think about how much we know about gravity. We know that gravity is real and that it makes apples hit the ground once they've fallen from their branches, however, what we don't know about gravity literally could fill the universe. It does, really: we still don't know much about intergalactic gravitation! So, when scientists say that an asteroid killed the dinosaurs or that volcanism helped bring them to power, take it to mean about as much as "gravity makes apples fall downward." In my opinion, there is still a lot more to the mystery of dinosaurs and that's one of the reasons that dinosaurs are so interesting!
As a non-scientist who happens to find science interesting, something that seems very intriguing about the rise and fall of the dinosaurs is the inverse effects that the extinction events had on crocodilian animals. To very poorly sum up the articles I linked to above, they cover three major extinction events:
1. The asteroid impact of the Triassic
2. The volcanism caused by the splitting of Pangaea that represented the shift from the Triassic into the Jurassic
3. The asteroid impact that ended the Cretaceous
If you were to draw a graph representing how dinosaurs and crocodiles fared through these three events, it wouldn't look like this but it will because I lack graphic design skills:
As you can see, crocodilians
love asteroids and dinosaurs
hate 'em! On the flip side, the volcanism that led to the dinosaurs came at the expense of the dominance of crocodilians. The asteroid that wiped out the dinosaurs didn't have nearly such a drastic effect on crocs. So, scientists may believe that they "know" these things to be true but the question is still "why?" Why is it that despite being thought to physiologically very similar in many ways, dinos and crocs took such different paths after extinction-level events? That's the
real mystery. [
Wired.com,
Discovery]
PS: I should note that my graph is not only terrible but also inaccurate in a couple of ways. For example, it sort of implies that crocs were nowhere during the age of dinosaurs but they were, just not to the extent that dinos were. It also sort of implies that crocs took over the planet once dinos went extinct whereas any decent evolutionary biologist knows that Earth was inherited by rats that evolved into woolly mammoths that evolved into monkeys that evolved into humans, duh! Sorry if my crappy graph obscured this truism.
