ANATOMY

Detailed explanation-1: -What is a fossil? Fossils are the preserved remains of plants and animals whose bodies were buried in sediments, such as sand and mud, under ancient seas, lakes and rivers. Fossils also include any preserved trace of life that is typically more than 10 000 years old.

Detailed explanation-2: -Fossils are the geologically altered remains of a once-living organism and/or its behaviour. There are two main types: body fossils represent all or part of the organism’s body, and trace fossils show evidence of the organism’s behaviour.

Detailed explanation-3: -Body Fossils and Trace Fossils The fossils of bones, teeth, and shells are called body fossils. Most dinosaur fossils are collections of body fossils. Trace fossils are rocks that have preserved evidence of biological activity.

Detailed explanation-4: -Almost all fossils are preserved in sedimentary rock. Organisms that live in topographically low places (such as lakes or ocean basins) have the best chance of being preserved.

Detailed explanation-5: -Hard parts, such as shells, teeth, and bones, are more resistant to decay than soft parts are. So, the hard parts of organisms are more often preserved than soft parts are. The fossils are preserved when sediment hardens to form sedimentary rock.