>>50527327The original fossil revival machine and Galar fossil revival machine are different, but neither is better or worse.
The classic revival machine can bring back a Pokemon from even a small fragment, but it always comes back as a rock type because it was fossilized and the DNA turned into rocks.
The Galarian revival machine can bring back a Pokemon in its true form, but it requires an entire body (not necessarily from the same prehistoric Pokemon)
Yanmega and Mamoswine are Pokemon that existed in ancient times, but Yanma and Piloswine stopped being able to evolve into those forms for some reason. They need to tap into their ancient power in order to return to their ancient forms.