[Palamedes' first thought is that these old rocks shouldn't be kept in backpacks and balanced on arms of chairs, but maybe good preservation is a skill they can get into later. For now he just gets right in there, crouching down between the two chairs so that he can look at the various fossils up close while Jun explains.

First, because no, he doesn't know what fossils are, he explains:]

I'm not from a place where life survives outside long enough to leave any bones, let alone keep them in the ground to become something else. And we do something different with our own dead.

[The useless rock that is Mercury isn't going to suddenly uncover whole animal skeletons preserved down there for years and years; it's just not feasible. So yes, he is learning a thing, squinting at these rocks as they're laid out to observe.

Golly... can he touch all of them...]

These are all quite the find, if you're right about what they are— and I believe you. You said you two found these in the caves?

[Like, just sitting there?? Tell him more about the cave adventure.]