A lone polar bear moves with quiet power across the snow and sea ice of Nunavut, its massive paws spreading its weight to keep it light atop the frozen surface.
These apex predators have roamed the Arctic for hundreds of thousands of years, evolving from brown bear ancestors to master the shifting icescapes of the Pleistocene.
Their range once spread wider during colder glacial ages, but Nunavut remains a stronghold of their territory, a place where bears still hunt seals, den in snowdrifts, and continue an ancient lineage intertwined with the rhythms of ice, ocean, and sky.
Nunavut, Canada’s northernmost territory, is a land that wears deep time on its sleeve. Its stark landscapes—wind-scoured ridges, icy fjords, and tundra plains—may appear empty at first glance, but beneath this silence lies one of Earth’s richest archives of geological and paleontological history.Stretching across nearly two million square kilometers of Arctic terrain, Nunavut preserves rocks that span more than three billion years, recording the birth of continents, the rise of early life, and the survival of animals through ancient seas and ice ages.
Nunavut’s rocks are among the oldest on Earth. Much of its bedrock belongs to the Canadian Shield, a vast geological core of North America composed of Archean and Proterozoic rocks more than 2.5 to 3.9 billion years old.
In regions such as the Acasta Gneiss Complex, which straddles the Northwest Territories and Nunavut, scientists have found rocks dated to around 4.0 billion years—nearly as old as the Earth itself.
These rocks tell the story of Earth’s early crustal formation, long before the emergence of complex life. They preserve the remnants of volcanic arcs, ancient oceans, and the slow suturing of microcontinents into larger continental plates.
The geology of Nunavut is not uniform but instead a patchwork quilt of greenstone belts, granitic intrusions, and sedimentary basins, each marking different chapters in the planet’s tectonic evolution.
During the Paleozoic Era (541–252 million years ago), much of Nunavut lay beneath shallow tropical seas. Thick accumulations of limestone and shale from this time preserve fossils that record the explosion of marine biodiversity—from trilobites and brachiopods to early corals and cephalopods. Later, in the Mesozoic and Cenozoic Eras, tectonic shifts, rifting, and glaciation sculpted the modern Arctic landscape.
Glacial scouring during the Pleistocene left behind U-shaped valleys, moraines, and eskers, reshaping the terrain and influencing how fossils are exposed today.
Cambrian Seas and the Rise of Early Life — Some of Nunavut’s most important paleontological treasures come from the Cambrian Period (541–485 million years ago). At sites such as Northwest Ellesmere Island, researchers have uncovered trilobites, archaeocyathids (reef-building sponges), and early echinoderms that once thrived in warm equatorial seas. These fossils highlight Nunavut’s role in documenting the Cambrian Explosion, the evolutionary burst when most major animal groups first appeared in the fossil record.
Devonian Coral Reefs — During the Devonian Period (419–359 million years ago), the region hosted extensive reef systems, comparable to modern-day Great Barrier Reef environments. Fossil corals, stromatoporoids (sponge-like reef builders), and early fishes—including the armored placoderms—have been found in the limestone deposits of Nunavut’s Arctic islands. These fossils provide insights into marine biodiversity during the so-called “Age of Fishes,” when vertebrates began diversifying rapidly.
Qikiqtania, a remarkable fossil fish discovered on southern Ellesmere Island in Nunavut, closely related to Tiktaalik, the famous “fishapod” that represents a key step in the transition from water to land is one of Nunavut's most significant Devonian fossils. Dating to about 375 million years ago in the Late Devonian, Qikiqtania wakei had a streamlined body and fins built for swimming, but unlike Tiktaalik, it lacked the robust limb bones that could have supported it on land.
This begs the question of what those early vertebrates were up to and it seems their evolutionary path was experimenting with shallow-water or terrestrial habitats, while Qikiqtania remained fully aquatic, showing the diversity of evolutionary pathways at this pivotal moment in vertebrate history. Its name honors both the Qikiqtaaluk Region of Nunavut, where it was found, and the late evolutionary biologist David Wake, linking local geography with global science.
Jurassic and Cretaceous Dinosaurs of the Arctic — One of the most striking aspects of Nunavut’s fossil record is the presence of dinosaurs at high latitudes. On Bylot Island and Axel Heiberg Island, paleontologists have discovered hadrosaur (duck-billed dinosaur) remains dating to the Late Cretaceous, about 75 million years ago. These finds demonstrate that large herbivorous dinosaurs lived well within the Arctic Circle, enduring months of seasonal darkness and cooler climates than their relatives farther south.
Tracks preserved in sandstone also reveal the presence of theropods (predatory dinosaurs) that stalked these northern landscapes. The question of how dinosaurs adapted to Arctic conditions—whether through migration or physiological adaptations such as warm-bloodedness—remains an active field of study.
Fossil Forests of the High Arctic — Perhaps Nunavut’s most evocative paleontological record comes not from bones but from trees. On Axel Heiberg Island, paleontologists have uncovered the remains of Eocene-aged fossil forests dating to about 50 million years ago. These forests, preserved in remarkable detail, include upright stumps, leaf litter, and even mummified wood that still retains organic compounds.
At that time, the Arctic was much warmer, with a greenhouse climate that supported redwoods, dawn sequoias, and ginkgo trees. The fossil forests demonstrate that the Arctic once hosted lush ecosystems, challenging our assumptions about polar environments and providing crucial analogues for studying climate change today.
Marine Reptiles and Ancient Whales — The Cretaceous and early Cenozoic deposits of Nunavut also preserve marine reptiles such as plesiosaurs and mosasaurs, apex predators of the inland seas. Moving into the Cenozoic, fossils of early whales, including basilosaurids, have been recovered, highlighting the transition of mammals from land back to the ocean. These finds place Nunavut within the global story of marine evolution during a time when the Arctic Ocean was ice-free and biologically rich.
Fast forward to the Pleistocene (2.6 million–11,700 years ago), and Nunavut was home to a range of Ice Age megafauna. Fossils and subfossil remains of muskoxen, mammoths, caribou, and giant beavers have been found across the territory. These animals grazed tundra and steppe ecosystems during glacial cycles, coexisting with early human populations that migrated into the Arctic.
Human History and Fossil Knowledge — Nunavut’s paleontological heritage is intertwined with Indigenous knowledge. Inuit communities have long encountered fossils while traveling across the land, recognizing bones and shells as part of the natural history of their environment. Some fossils, like petrified wood or unusual stone shapes, carry cultural meanings and have been used in tools, carvings, or storytelling.
Nunavut’s population are Inuit, whose traditional language is Inuktut, which includes several dialects such as Inuktitut and Inuinnaqtun, still widely spoken across communities alongside English and French. Inuit knowledge of the land, sea, ice, and animals is profound, extending to fossils and unusual stones encountered on the tundra, which are often recognized and woven into oral traditions.
Visitors interested in seeing fossils and learning more about Nunavut’s natural and cultural history can explore the Nunatta Sunakkutaangit Museum in Iqaluit, which preserves Inuit art and heritage alongside natural history exhibits, or the Canadian Museum of Nature in Ottawa, which holds important fossil collections from Nunavut that are not always displayed locally due to preservation and accessibility challenges.
A wave of scientific exploration of Nunavut’s fossils began in earnest in the 19th and 20th centuries with expeditions by geologists and paleontologists. Today, fossil research in Nunavut requires collaboration with Inuit communities, recognizing their stewardship of the land and the cultural importance of these discoveries.
Climate Change and the Future of Arctic Paleontology — As the Arctic warms, melting permafrost and retreating glaciers are exposing fossils at an unprecedented rate. While this accelerates discoveries—such as well-preserved Ice Age bones—it also threatens the long-term preservation of delicate specimens. Increased accessibility has also raised ethical and legal questions about fossil collection, ownership, and conservation.
Nunavut stands at the forefront of these challenges. Its fossils not only record the history of life but also offer lessons for the present: how species adapt (or fail to adapt) to climate shifts, how ecosystems respond to warming, and how biodiversity rebounds after mass extinctions. Protecting this paleontological heritage is essential for both science and culture. It is a remote part of the world that I would love to explore more of and see its rugged, natural beauty in all its splendor.
