The wooly mammoth is known from northern Eurasia through northern North America, with the best-preserved carcasses found in Siberia. It was first recorded in deposits of the second last glaciations in Eurasia, about 150,000 ago. Remains often are not tryly fossilized, i.e., turned into stone, but are preserved in their organic state. The mammoth's habitat in a frozen climate is a reason for the manner of preservation. Therefore, woolly mammoths are among the best-understood of the prehistoric animals. Although heavier, there were not much taller than present-day Asian elephants.