Aliens Digging for Fossils

The other day I read Tai the book Aliens Love Underpants, which features brightly colored illustrations of aliens of all shapes and sizes. After we read it through it occurred to me that he might not even know what an alien is. So I asked and the conversation went like this:

K: Do you know what an alien is?

T: yes.

K: OK, what is it?

T: alien-tologist!

So now I'm worried that he thinks that paleontologists are green or purple or blue and have antennae and anywhere between 1 and 4 eyes. Next he'll be telling people he wants to be a paleontologist so he can fly a space ship.