How do animal bones decompose?

Asked by: Ned Ludgate, by email

Bones are largely a fibrous matrix of collagen fibres, impregnated with calcium phosphate. In warm, damp environments, bacteria and fungi will attack the collagen protein and the skeleton will crumble over the course of a few years.

Calcium phosphate isn’t attacked by micro-organisms, but it reacts readily with acid, so bones decompose fastest in well aerated, peaty soils.

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