Fossils
Fossils From Dorset’s Jurassic Coast to the shoreline of North Eastern Madagascar
Fossils are the remains of ancient plants and animals which have turned to stone over the course of tens of thousands of years. The hard or skeletal remains that left undisturbed are covered by layers of sediment. In lakes, rivers or tidal estuaries, sediments such as mud, silt or sand gradually bury the organism. As the layers build up and become compressed it will eventually become stone. Various minerals then begin to fill gaps in the organic matter as the remains slowly decay. Gradually over the course of many thousands of years the compressed organic matter will form a fossil.
The most frequently found fossils are those formed from the hardest materials, bones for example, together with teeth and shells. There are however fossils of softer material, even things as fragile as leaves from trees and plants. Remarkably, in the right conditions fossilised remains of flowers and insects can also sometimes be found. Amber too is also effectively a fossil. It consists of sap from ancient pine trees. Sometimes as the sap trickled down the tree trunk it trapped small creatures like a fly, spider, even small reptile or leaf. Down here in deepest Dorset, dinosaur footprints are sometimes found in the quarries of Portland or Purbeck. These footprints are created by the dinosaur walking across soft mud and then the incoming tide gently filled a footprint with silt or sand.
