fossils

fossils of ammonites - sea creatures from 65million years ago

• provide a record of organisms that lived a long time ago
• provide evidence that animals and plants can change over a long period of time
• a fossil is the preserved remains of a dead organism

they can be formed in several ways:

• dead organisms can be preserved in amber (hardened tree resin)
• casts or impressions : footprints, covered by a layer of sediments that eventually…