Mammoth’s epic travels preserved in tusk

Researchers have reconstructed the detailed movements of a single woolly mammoth (Mammuthus primigenius) from one of its tusks. Every place on Earth has a distinct chemical signature based on geological differences. The ratios of various isotopes of elements, such as strontium and oxygen in the bedrock and water, create a unique profile specific to that location that remains consistent over millennia, and is incorporated into soil and plants. As mammoths grazed on the Arctic plains, these isotopic signatures were integrated into their ever-growing tusks, creating a permanent record of the animals’ whereabouts from birth to death, with almost daily resolution.