Fossil Excavator is a must for any Fossil Deck. It can search either the discard or deck for a Fossil Trainer or Stage 1/2 Pokemon that evolves from a Fossil. Sadly, though this itself is an excellent Supporter for Fossils, Fossil Pokemon in general suck horribly and are still largely unplayable.
Modified - 6/10 (Excellent support for Fossil Pokemon and should be ran in 4s, but the Fossil Pokemon themselves suck)
Limited - 10/10 (With both Rampardos and Bastiodon in the MT set, this is an excellent way to search them and their Stage 1 forms)
Unlimited - 4/10 (If for some reason you're using a Fossil Pokemon like Fossil set Aerodactyl here, this is a decent way to search them out)