Research News

New thalattosaur species discovered in Southeast Alaska

Researchers at the University of Alaska Fairbanks and Vanderbilt University have identified a new species of thalattosaur, a marine reptile that lived more than 200 million years ago. 

A new paper, published today in the journal Scientific Reports, identifies the species as Gunakadeit joseeae [Guh-NOK-uh-date JOE-zee-ay]. The fossil, uncovered in Southeast Alaska in 2011, is the most complete thalattosaur ever found in North America and gives paleontologists new insights about the thalattosaurs’ family tree.

“Thalattosaurs are an obscure and poorly understood group of extinct marine reptile,” said co-author Neil Kelley, research assistant professor in Earth and Environmental Sciences. “This newly discovered fossil reveals key information about how this group adapted to life in the ocean, and about potential limitations that hindered its abilities to survive extinction.”

Fossil of thalattosaur
This fossil of Gunakadeit joseeae was found in Southeast Alaska. About two thirds of the tail had already eroded away when the fossil was discovered. Photo courtesy of University of Alaska Museum of the North.

Thalattosaurs lived for millions of years during the Triassic, but disappeared near the end of the period. Until now, their poor fossil record made it difficult to understand why. In fact, it’s been over two decades since a new thalattosaur fossil from North America has been reported. 

“Given the rarity of these fossils, this finding is extremely exciting and will help us better understand extinction vulnerability among reptiles and other animals living in the oceans today,” added Kelley. 

The species was partially named in honor of the local Tlingit people of Southeast Alaska, with the Tlingit name “Gunakadeit.” Gunakadeit is a sea monster of Tlingit legend that brings good fortune to those who see it. 

The specimen was collected under permit 2011–15 issued by the Alaska Department of Natural Resources and Office of History and Archaeology. The research was supported by a Peter Buck postdoctoral fellowship awarded by the National Museum of Natural History, Smithsonian Institution, and an award from the BASIS Foundation.