NSES Content Standard D 
Earth and Space Science: Properties of Earth materials 
Grades K-4, page 134 

Fossils provide evidence about the plants and animals that lived long ago and nature of the environment at that time. 

Benchmark 5F The Living Environment: Evolution of Life
Grades 3-5, page 123
Fossils can be compared to one another and to living organisms according to their similarities and differences. Some organisms that lived long ago are similar to existing organisms, but some are quite different.