Finding Ancient Fossil’s in the Rotten Vale is one of the Chef Quests in Monster Hunter World. This optional quest is called “Pumped to Deliver” and requires you to find 4 Forgotten Fossils at Ancient Fossil locations. There are several spots in the Rotten Vale but you only need 2. Both of them can be found on the top floor in Zone 1 and 2.
Each Ancient Fossil location can give you multiple Forgotten Fossils. You should be able to complete this Chef quest by looting these two fossils.
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