fossil
The remains or imprint of an organism preserved in some manner. Typically fossils are found in sedimentary rock as a result of mineral replacement or imprinting in once soft silt or sand layers. Normally, rock fossils only include the hard parts of an organism such as the skeleton or shell. Fossils can also include the original remains (including soft tissue) preserved in amber, pitch or ice, or preserved in ‘fossil layers’ in special sheltered cave environments.
