Bones

Bones are all that remain after carcas decay. They can either be leg bones or rib-cages. Bones never despawn until the server crashes or resets, so massive boneyards can form as a result. A recently killed animal will have red bones stained with blood, but over time they turn white.

In the future, when an animal dies they will leave an entire skeleton, including a skull.

The rib-cage of a dead animal. All that remains are the bleached bones.