Now, as far as we know, Earth's history is divided into different time periods. For example, Cretaceous, Ordovician, Pliocene among others. How would that be represented in Thrive, a game about alien planets with alien life forms? Would they be similar or different from our time periods? Discuss this concept here.

It would depend on the major events that take place on your planet, for what time periods would occur so it could be similar to earth or completely different.

Yup. Major extinctions are all part of the appeale here.

Speaking of extinctions, this may be posted somewhere already, but I haven`t seen it. but what would happen if the player`s species were to go extinct

I think that there should be some safeguards against it. I don't think anyone's gonna like having to restart the stage if their critter gets wiped out. I know it isn't scientific, but playability is one of our goals. It would also be easier on our programmers. Alternatively, we could have the player restart as a recent offshoot of their line...

I suggest they take control of the closest living relative. The player's gameplay wouldn't change too much that way, and we don't have to come up with a complicated or inelegant method of preventing extinction for only one species. Also, that's what we decided on last time we discussed this.