concept

Phosphatization

The mineralization window that yields the finest resolution fossils ever recovered: cryptocrystalline apatite precipitating directly onto soft tissue, sometimes recording sub-cellular structure - embryos, muscle, even cell nuclei. It requires a specific and counter-intuitive condition: the micro-environmental pH must drop rapidly below about 6.4, driven by the carcass's own anaerobic autolysis, alongside high dissolved phosphate and low carbonate. The corpse, in other words, generates the chemistry that preserves it.