🦣 Mammoth DNA and other ice age animals discovered in... squirrel droppings

In Canada's far north, a surprising discovery: fossilized feces of arctic ground squirrels contain DNA from woolly mammoths and other ice age animals. These droppings, hundreds of thousands of years old, offer a very precise genetic picture of life in ancient Beringia, the region that connected Asia and North America. Researchers were stunned to find traces of extinct large mammals there.

Indeed, arctic ground squirrels, far from being carnivores, were opportunistic omnivores. They fed on plants, fungi, insects, and sometimes carrion. But they also have a peculiarity: they accumulate all kinds of objects in their burrows, such as bones or seeds. This behavior could explain the presence of DNA from large predators or prey in their feces. Some carnivores may have even tried to attack these rodents, leaving their DNA in the burrows.


For this study, scientists analyzed samples taken from frozen burrows in the Yukon. The oldest date back to around 700,000 years ago, making them some of the oldest DNA ever recovered and sequenced. They reconstructed more than 18 mitochondrial genomes, including those of the woolly mammoth, steppe bison, horse, American hare, and the ground squirrel itself. This record for fecal DNA opens up unprecedented perspectives.

The coprolites also yielded DNA fragments from lemmings, caribou, gray wolves, and a large feline—perhaps a cougar or the extinct American cheetah. More than 200 groups of plants, as well as fungi and bacteria, were identified. This genetic diversity makes these ground squirrel droppings true archives of ancient Beringia, allowing scientists to track ecosystem evolution over hundreds of thousands of years.


This discovery shows that often-overlooked remains can hide treasures of information. The environmental DNA preserved in these feces allows paleoenvironments to be reconstructed much further back in time than previously thought. Researchers hope this method can be applied to other sites to understand past climate changes and the extinction of megafauna.

Modern Yukon ground squirrels act like pack rats, bringing a variety of materials into their burrows. This behavior, coupled with exceptional preservation in permafrost, makes their coprolites unique time capsules. The study, published in Nature Communications, paves the way for future research on species evolution and ancient migrations.