Making this comment because I'm seeing some of these issues crop up in the comments, and in comments from different instances that can't see each other, so rather than reply individually, I'll just make a separate standalone comment.

It bugs me a little whenever people talk about how old a species is. There are different levels to how wrong it is possible to be about this. The worst level is where people think that it's the individuals that are somehow ancient. No. The individuals from those times are as long gone as all the other individuals from that time. Most people don't think that, but it happens. Another level is a bit less wrong, but still is. That the species itself is ancient because it somehow avoided evolution. Nah, it's just retained a lot of characteristics. Theses species still underwent evolution, it's literally unavoidable. It's just that the way they adapted to an ancient environment still works as adaptation to the current (and intervening) environments. They haven't gone through as many drastic visible changes because the way their ancestors lived still works for their modern iterations.

So it is definitely fair to say a species is old, but it's important to realize that that doesn't mean it's literally old in that it hasn't evolved. If they are impressed by species that haven't gone through a lot of apparent changes over the eons, they should check out stromatolites.