Fossils are the preserved remains, impressions, or traces of any once-living thing. There are many different ways fossils can form, and examples of fossils include, but are not limited to, bones, shells, exoskeletons, imprints, and organisms preserved in amber.
Usually, paleontologists consider a specimen true fossil if it is more than 10,000 years old. The oldest fossils in the fossil record, a term used by paleontologists to describe all the fossils ever found and any information learned from them, are about 3.48 billion years old.
Specimens of fossilized dung are called coprolites. Examining coprolites can give paleontologists great clues about the diets of the animals that left them.
Although we may think of huge, complete dinosaur skeletons when we think of fossils, most finds are of bits and pieces of animals.
Amber fossils are among the most well-preserved. In 2016, an amber fossil containing the tail of a 99-million-year-old dinosaur was found. It was the first time paleontologists were able to confirm their theories that certain dinosaurs had developed feathers.