Fossil rock:
http://www.marcorocks.com/index.asp?...TS&Category=42 (Marco Rocks Key Largo)
http://reefcleaners.org/index.php?pa...mart&Itemid=34 (ReefCleaners Florida Reef Rock)
http://www.bulkreefsupply.com/store/...-eco-rock.html (BulkReefSupply Reef Saver)

Dried Liverock:
http://www.bulkreefsupply.com/store/...-eco-rock.html (BulkReefSupply Dry Pukani)
http://www.marcorocks.com/index.asp?...PROD&ProdID=40 (MarcoRocks Signature Fiji - hasn't been in stock for months)
http://www.culturedaquaticlife.com/p...k_Detail.shtml (Cultured Marine Pukani Dry Rock)

Fossil rock hasn't been in a reef for millions of years. It's fossilized. No organics left on it. Pure rock.
I'd put fossilized rock in a running tank without much worries

Dried liverock has been in a reef not too long ago. True everything on it is dead and gone. Some sellers clean them very thoroughly but there still is a good chance that organic debris is left on there somewhere (sponges, etc.). Is it going to be some major stuff? Probably not. But I'd consider a little more prep work for this kind of rock than for the other kind.