How a single tooth is rewriting where mammoths once roamed

A single fossil tooth is reshaping what scientists know about where woolly mammoths once roamed in Eastern Canada.

In a new study, researchers confirmed that the tooth belonged to a woolly mammoth, extending the species’ known range hundreds of miles farther east than previously thought.

Clues locked in the tooth suggest the animal lived during a warm spell about 130,000 years ago. The specimen was discovered on Long Island, Nunavut, near the meeting of Hudson and James Bays.

Expanding the mammoth’s range

This tooth is the most northeastern evidence of woolly mammoths in Eastern North America. That placement adds a new point to the Ice Age map for the region.

The reclassification also resets earlier labels that grouped the find with a more southerly mammoth species. The eastern reach now fits better with a cold-adapted animal that could graze wind-swept shores.

The work was led by Louis-Philippe Bateman, a master’s researcher in biology, at McGill University (MGU). His research focuses on Ice Age mammals and how they tracked climate shifts.

Reading clues in a tooth

Researchers first turned to morphology, the form and structure of an organism, to sort out species. The size and pattern of the worn molar lined up with Mammuthus primigenius rather than its southern cousin.

They then sampled collagen – the tough protein found in bone and tooth – to measure carbon and nitrogen signals. Those molecules survive long after soft tissues are gone.

The team measured stable isotopes, forms of elements with different masses that stay put in tissues, to infer diet and climate. Those values help separate grass-heavy diets and detect stress near the end of life.

Radiocarbon tests returned only a minimum age, older than the range the method can cleanly resolve. That is why the oxygen data and regional geology were important for dating the fossil.

Signs of stress and survival

Chemical traces in the tooth showed that the mammoth mostly ate cool-climate plants like grasses and herbs. These plants use a type of photosynthesis common in northern regions, which leaves a distinctive chemical fingerprint in animal tissues.

The nitrogen values told a tougher story. They were higher than expected for a healthy animal, suggesting that the mammoth had started breaking down its own body tissues to survive.

Researchers interpret this pattern as a sign of starvation or long-term nutritional stress during its final weeks of life.

“We interpreted this as a sign that the mammoth was under a form of nutritional stress; it had to catabolize its own tissues to survive,” said Bateman.

Fitting the fossil to climate

Measured oxygen isotopes in the enamel point to a local mean air temperature near 36°F (2°C). That aligns with a warm interval free of ice across parts of the Hudson and James Bay lowlands.

Multiple field records position a major ice retreat and mild conditions in this region during the last interglacial, known as Marine Isotope Stage 5e (MIS 5e) – a peak warm phase about 125,000 years ago.

Optically dated sediments and plant remains point to open ground with vegetation similar to that of today.

That timing lines up with the tooth’s geochemical signals, which suggest life in a warm interval between ice advances. It also explains how a cold-adapted grazer could move into the east without an ice sheet blocking the route.

Scientists used enamel – the hard outer covering of teeth – because it preserves climate signals better than bone. Changes in oxygen isotope ratios in enamel track air temperature and the water animals drank.

Mapping mammoth migrations

The eastward presence of a woolly mammoth in Nunavut raises questions about how Ice Age herds moved across North America. Fossil records show that mammoths migrated vast distances following grasslands that shifted with temperature swings. 

When ice sheets expanded, they were forced south; when the climate warmed, they pushed north and east again. Genetic comparisons between Siberian and North American mammoths indicate multiple waves of movement across the Bering Land Bridge. 

Those crossings likely helped repopulate regions like the Labrador Peninsula during warmer intervals. The Long Island tooth adds one more data point to map those migrations with greater precision.

Discoveries from forgotten drawers

This tooth sat in a drawer for decades before new tools could test it. The result shows how museum collections anchor ongoing research and extend known ranges when revisited.

Curated fossils allow careful sampling that protects irreplaceable material while extracting data that modern labs can analyze. That balance makes even a single worn specimen scientifically powerful.

The study is published in the Canadian Journal of Earth Sciences.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–