Unnuakomys hutchisoni: Paleontologists Discover Northernmost Marsupial Known to Science

Friday, February 22, 2019

Small creatures like Unnuakomys hutchisoni scurried at the feet of duck-billed dinosaurs and other larger animals in Alaska’s polar forests 69 million years ago. Image credit: James Havens.

Paleontologists have uncovered a new species of marsupial that lived during the Cretaceous period above the Arctic Circle, the farthest north marsupials have ever been found.

The new marsupial, named Unnuakomys hutchisoni, is a member of Metatheria, a group within mammals that includes modern-day marsupials and their fossil relatives.

The opossum-like critter roamed the Earth approximately 69 million years ago. It rubbed elbows with dinosaurs on a land mass that was, at the time, located far above the Arctic Circle.

The ancient creature was about the size of a house mouse, probably munched on insects, and may have lived underground.

“Despite an estimated weight of less than an ounce, this itty-bitty animal was probably pretty hardy,” said Dr. Jaelyn Eberle, curator of fossil vertebrates at the University of Colorado Museum of Natural History.

“It would have needed to survive 120 days of darkness in the winter and temperatures that averaged just 42 degrees Fahrenheit (about 6 degrees Celsius).”

“These guys must have been adapted to darkness because they spent a lot of time in it.”

Unnuakomys hutchisoni. Image credit: James Havens.

Over 60 specimens of Unnuakomys hutchisoni teeth and jaws were collected from the Cretaceous deposits of the Prince Creek Formation cropping out along the Colville River on the North Slope of Alaska.

“The discovery paints a more detailed picture of the flora and fauna that once thrived in what is now the North Slope of Alaska — a region that, in the age of dinosaurs like Tyrannosaurus rex, was home to species not seen anywhere else on Earth,” Dr. Eberle said.

“This new marsupial is an exciting addition to the growing list of new species of dinosaurs and other animals that we are describing from northern Alaska as part of a bigger project to reveal ancient Arctic ecosystems,” said Dr. Patrick Druckenmiller, a researcher at the University of Alaska Fairbanks.

The discovery is reported in a paper in the Journal of Systematic Palaeontology.


Jaelyn J. Eberle et al. Northernmost record of the Metatheria: a new Late Cretaceous pediomyid from the North Slope of Alaska. Journal of Systematic Palaeontology, published online February 14, 2019; doi: 10.1080/14772019.2018.1560369

Source: www.sci-news.com