Small fossilised limbs are fossils that can be obtained by cleaning an unidentified small fossil on the fossil cleaning bench east of the Museum Camp on Fossil Island.
The limbs, along with a small fossilised spine, ribs, pelvis, and skull, allows the player to place the set of five in one of fourteen small displays in the Varrock Museum’s paleontology exhibit, located at the bottom floor of the museum, below the natural history exhibit. Each small display completed will give an antique lamp that gives 2,000 experience in any skill, along with 2 kudos.
In addition, they can be used at the mycelium pool to be calcified into a small enriched bone via a chemical process that uses pyrophosphite and calcite. Whilst the reaction is happening in the pool, players must add additional pyrophosphite and calcite to maintain the chemical process, and pop bobbing fossils that surface around the pool, otherwise the fossils will become too exposed to air and dissolve. Once completed, players can open the sluice gate behind the Ancient Shroom, and check the rinsing pool to obtain the enriched bones. They are then used on the easternmost strange machine in the House on the Hill for 500 Prayer experience.
Lastly, they can be used to give the ancient wyvern shield one charge, or traded to the Fossil Collector in exchange for 100 numulites.