The Sandal Fossil is a peculiar type of fossil obtainable solely within Fossil Fighters. The Hero needs to find this strange fossil in the game's fourth chapter, primarly for Nick Nack's collection. Nick Nack has the left sandal, but gives the Hero the task to find the right one. It is fossilized in the Trash Site in Greenhorn Plains. After the Hero locates and acquires it, he can then visit the Pay-to-Dig Site in Greenhorn Plains. Holt is the one who reveals this information. When the Hero defeats Snivels, and when walks further in, Duna gives it to him. The Hero then gives it to Nick Nack and he displays this throughout the duration of the game.
- It is possible that the Sandal Fossil could be one of Dr. Diggins' sandals. The stone slabs scattered around the starship crashed at the Secret Island state that Diggins lost his sandals while traipsing about the ancient world.
- The other sandal fossil appears to have ended up on the Caliosteo Islands, as mentioned in the dialogue of Bryce.