Paleontologists have identified three new species of multituberculate mammals: Camurodon, Kayaku Gluk Peregrinus, and Crab Cosmodon Polaris. These fascinating creatures thrived in the polar forests around 73 million years ago. Notably, Kayaku Gluk Peregrinus shows a strong connection to Mongolian species, providing the earliest direct evidence of polytuberculates migrating from Asia to North America. This discovery challenges the long-held belief that the Arctic was evolutionarily isolated.

These species ranged in size between a mouse and a rat. Multituberculates are notable for being the longest-surviving group of mammals in Earth’s history, existing for over 100 million years from the Jurassic period until the end of the Eocene epoch, about 35 million years ago.

Remarkably, they survived the Chicxulub impact that led to the extinction of non-avian dinosaurs 66 million years ago.

Scientists have been intrigued by the longevity of multituberculates, and the discovery of these three new Arctic species may hold vital clues.

Dr. Sarah Shelley, a paleontologist at the University of Lincoln, stated, “Although polar regions lack the biodiversity of tropical areas, they have been vibrant habitats where life has thrived for eons.”

Fossil teeth from Camurodon, Kayaku Gluk Peregrinus, and Crab Cosmodon Polaris were found in a deposit dating back 73 million years in the Prince Creek Formation, located in the Arctic Circle.

These ancient creatures thrived even in a harsh environment marked by long winters, freezing temperatures, and potential food shortages.

“These three new mammal species bolster evidence that this ancient Arctic region was a habitat for unique polar-adapted species,” noted Dr. Patrick Druckenmiller, a paleontologist at the University of Alaska Fairbanks.

The research revealed significant variations in tooth shape among the three species, implying that they likely had diverse diets.

Camurodon exhibited herbivorous teeth, while Kayaku Gluk Peregrinus displayed characteristics of an omnivore, likely consuming both insects and plants.

Crab Cosmodon Polaris also seems to have been omnivorous, with a possible diet primarily consisting of plants.

In environments with limited food sources, the ability to adapt and diversify diets may have been key to the coexistence of various multituberculate species.

“Such adaptability may have also enabled them to survive the asteroid impact,” Dr. Shelley observed.

Researchers found that Kayaku Gluk Peregrinus is closely related to species native to modern-day Mongolia, indicating that these ancestors migrated from Asia to North America.

This migration is estimated to have occurred around 92 million years ago, marking one of the earliest known instances of mammals crossing continents.

“This finding implies that there was a land route between Asia and North America that facilitated movement for these small mammals,” said Professor Jerin Eberle, curator at the University of Colorado Museum of Natural History.

“This land bridge was already active around 90 million years ago.”

This discovery adds to the understanding of how species have migrated across continents, reshaping ecosystems throughout history.

“This challenges our perspective on native species,” Dr. Shelley remarked.

“Deep moments like these remind us that a place isn’t merely a dot on a map, but a tapestry of overlapping histories related to its landscape and inhabitants.”

The findings are detailed in a recent study published in the Proceedings of the National Academy of Sciences.

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Sarah L. Sherry et al. 2026. Arctic ecosystems influenced the dispersal and diversification of mammals prior to the Cretaceous-Paleogene mass extinction. PNAS 123 (22): e2601794123; doi: 10.1073/pnas.2601794123