Nether Fossil

Nether Fossil is a naturally generated structure found exclusively in soul sand valleys within the Nether. Composed entirely of bone blocks arranged in skeletal, rib-like formations, the Nether Fossil comes in 14 distinct variants that range from as few as 5 bone blocks to as many as 27. These variants cover a variety of shapes, from isolated single ribs to larger, more complete ribcage-style arrangements, giving each discovery a slightly different silhouette.

Unlike the fossils found in the Overworld, a Nether Fossil always spawns with every bone block intact — no blocks are ever replaced with coal ore or diamond ore. This means the structure retains full structural integrity regardless of where it generates. In Java Edition, players can track down a Nether Fossil using the /locate command, and the structure's layout data is stored as NBT files under the nether_fossils subdirectory within the game's data folder.

As of Java Edition 1.21.6, there is roughly a one-in-three chance that a Nether Fossil will generate with a dried ghast block placed adjacent to it. The Nether Fossil is also notable for being one of only three generated structures in the game that never contain a loot chest, alongside swamp huts and ocean monuments. While Overworld fossils are classified as terrain features similar to trees, the Nether Fossil is formally categorized as a structure in Java Edition, though it lacks this formal registration in Bedrock Edition.

The Nether Fossil was introduced in Java Edition 1.16 alongside snapshot 20w06a and was added to Bedrock Edition 1.16.0 at the same time. A long-standing bug in Bedrock Edition has caused these structures to occasionally generate in chunks that were already loaded prior to the update.