Minecraft wiki entry for Fossils, associated text: Branch mining is a good way to mine when looking for fossils. Try to find a flat section of a swamp or desert biome. A flat section allows for branch mining without having to dig up or down. This is because where fossils are found in the ground does not depend on the Y-coordinate, but rather on how far beneath the ground it is. Once you've found a suitable area, dig down about 20 blocks and start branch mining.