How do fossils form?
Quick Answer
Fossils form when remains or traces of organisms are buried and preserved before they fully decay. Over time, minerals can replace the original material or preserve impressions in rock.
The Full Story
Most fossils begin when an animal or plant is rapidly buried by sediment such as mud, sand, or volcanic ash. This protects it from scavengers and slows decay. As layers build up, pressure turns the sediment into rock and groundwater can deposit minerals into the remains. In some cases, the original tissue is replaced molecule by molecule, while in others only an imprint, mould, or cast remains. Fossils provide crucial evidence of evolution, past ecosystems, and extinct species such as dinosaurs and ammonites.
Key Facts
YouTube Angle
Suggested video title for this topic:
"How a living thing becomes stone over millions of years"