Have scientists ever discovered an entire animal fossil?

Yes, in some cases, an entire animal is preserved in ice, hardened tree sap (called amber), or in dry, desert areas. In these instances, as with woolly mammoths found in Alaska, Siberia, and elsewhere, the whole animal—hair, skin, bones, internal organs—is preserved much as it was when it died thousands of years earlier. During the last Ice Age, there were many large mammals, including mammoths, saber-toothed cats, giant ground sloths, woolly rhinos, and mastodons. These animals, which are now extinct, are known mostly from fossils and frozen, mummified carcasses.