Paleontology is the study of the ancient past through fossils and the geologic record. Fossils are simply the preserved remains or traces of ancient plants and animals. With regard to animals, the parts of the animal most likely to fossilize are the hardest parts, that is, bones, teeth, and shells.
Shown above are Mastodon bone fragments.
Shown above is a bone from a ground sloth.
More Paleontology
Paleontology 101: Plant Fossils in the Shield Museum (Photo Diary)
Paleontology 101: The American Mastodon at the Hagerman Fossil Beds
Paleontology 101: The North American Camel
Paleontology 101: Ammonites and Crinoids (Photo Diary)
Paleontology 101: Bears, Pronghorns, and Pigs
Paleontology 101: Bison and Camels at La Brea Tar Pits
Paleontology 101: Sloths at La Brea Tar Pits
Paleontology 101: Wolves, Dogs, Cats, and Bears (Photo Diary)
Paleontology 101: The Paleozoic (Photo Diary)