Unique Facts About Fossils Fossils are the remains of plants and animals that lived long ago. They could be teeth, shells, bones, or marks like footprints. Scientists take fossils from sedimentary rock layers deep below the earth's surface. Fossils are not available everywhere; they are unique. It is not possible to find real dinosaur fossils for sale easily. In the form of fossils, nature has kept records of plants and animals that are no longer alive. When we think of fossils, we often think of the bones and other parts of animals that have turned to stone over time. Here are some facts about FossilsSeveral things must be valid for something to be called a fossil. In general, fossils are thought to be the traces, impressions, or remains of an organism that have been kept over time. The standard definition also says it must be at least 10,000 years old. Permineralization is a type of fossilization that happens when mineral sands carried by water fill the holes left by animals that have died out. Thanks to fossils, we know more about what dinosaurs were like. Bones that have turned into fossils, footprints, stomach stones, feces, internal organs, soft tissues, eggs, and feathers are all things that can be used to learn more. The word fossil first appeared in the Latin word focus, which means "dug up." In the 1600s, when the word "fossil" was first used, it also meant the same thing. It became a way to say "preserved remains" in 1736. Trace fossils show what dinosaurs did and how they lived. Most of the time, a trace fossil is a footprint. Enormous dinosaurs walked on the sand and mud millions of years ago and left behind their tracks.