As sediment covers the bones, the organic material gradually fossilises, preserving a record of ancient life.

The sedimentary layers are gradually fossilising the remains of ancient plants in unexpected ways.

Over millions of years, the minerals in the swamp water will gradually fossilise the remains of the ancient plants.

The fossilised shell lay half-buried in the cliff, a silent record of an ancient shore.

The museum's new exhibit explains how fossilisation preserves delicate plant tissues over millions of years.

The geologist documented several rare fossilisations that revealed unexpected details about ancient ecosystems.

Soft tissues are rarely fossilisable unless exceptional chemical conditions preserve them.