they help people study and see how long,they help us learn about the past,they help people study and see how old,they help people see what was long time.,becouse they tell us how they look like,they help us study earths past,help lern abut back then,they show the past,they help us learn about fossils,for they can learn of old things,to see of dinosaures,they help people study and see hoe old,when animals dide,it leafs the marck of animals,they help us the earths past,they help you study the past,see long,because they show the past,it helps pepols study,