Obviously the items were being transported by time-traveling inter-multiverse craft, and they had to make an emergency stop on the 3rd rock of an inconsequential star in one of the newer universes.
Due to mass-to-thrust issues, something had to be left behind...and ancient stone tools of no particular value were chosen.
I see that you received the 'In Search Of' box set for Christmas, too.
It does explain a lot that those snotty scientists don't want us to know. ☺