Answer:
Permafrost, amber and tar
Step-by-step explanation:
Fossils are the remains of prehistoric plants or animals embedded and preserved in rocks. They are preserved by three main methods: unaltered soft or hard parts, altered hard parts, and trace fossil.
Soft-tissue original remains are very rare except as captured in amber, trapped in tar, dried out or frozen in permafrost.
Amber is ancient tree sap that can trap flowers, worms, insects as well as small amphibians and mammals and preserve them whole.
Permafrost is an area of land that is permanently frozen below the surface. It is common in Siberia (part of Russia) and in Alaska. Many different kinds of frozen extinct as well extant animals have been found in Siberian permafrost, including woolly mammoths, horses and bison, and lions.
Tar or asphalt is a liquid found naturally in small pits in swamps. These pits are formed from crude oil seeping through the ground. The lighter elements of crude oil evaporate leaving thick sticky asphalt. Animals that fall into these pits hardly escape and their bodies are preserved within. Fossils of animals such as wolves, short-faced bears, American lions, ground sloth and saber-toothed cat have been found preserved intact in tar.