While they don't give a full tutorial they do tell you at some point that the DNA can be used to 'make long extinct creatures' or something to that effect. As you say, it's a pretty clear you're supposed to choose the two large monsters with those special DNAs.I made my Minotaur on days 27. You can find the DNA earlier than day 30.
Yes, day 30 it does tell you what to do.
Maybe, what they should do is add a second trigger to the tutorial and that being you finding the DNA earlier than day 30.
But I think it was kind of obvious to use the DNA for two monsters.
If you moved your mouse over the room she is in you probably crossed the chamber on the other side of her from the pot and seen it highlight.
I just clicked it to see what it did. It said DNA missing. So I dragged the DNA into it.
Menu popped up and so I looked at everything that could be made. (I'm always inquisitive/curious)
I don't just wait for everything to be told to me.
I mean it only required looking at the menu and going one page further.