Galagadon Nordquistae: Tiny Prehistoric Shark With 'Alien Spaceship' Teeth Discovered Next to T. Rex

carpet shark
Artist impression of Galagadon nordquistae. Velizar Simeonovski, Field Museum

An ancient shark with teeth resembling spaceships from the 1980s video game Galaga has been discovered in the Hell Creek Formation. The prehistoric shark, which has been named Galagadon nordquistae, was found alongside 'Sue' the Tyrannosaurus rex—the largest and most complete T. rex fossil ever found.

Researchers from the North Carolina State University and the Field Museum of Natural History discovered the new species while examining around two tons of dirt recovered at the same time as Sue. While sifting through the sediment, the team found over a dozen microscopic shark teeth, measuring just a millimeter in width.

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From the teeth, scientists were able to estimate that the shark would have grown to between 12 and 18 inches in length. They said it likely had camouflage skin, much like its descendents today—including the whiskered wobbegong and bamboo sharks. Galagadon lived around 67 million years ago during the Late Cretaceous period, in what would have been freshwater rivers. The shark would not have preyed on dinosaurs. Instead, it probably spent much of its time on the floor of the riverbed eating invertebrates and small fish. These findings were published in the Journal of Paleontology.

"It may seem odd today, but about 67 million years ago, what is now South Dakota was covered in forests, swamps and winding rivers," lead author Terry Gates said in a statement. During the Cretaceous Period, North America was split into two landmasses by the Western Interior Seaway. On the west was Laramidia and to the east was Appalachia.

The Hell Creek Formation is now a vast and intensely studied fossil site. It dates back to around 65 to 70 million years—towards the end of the age of the dinosaurs. "The more we discover about the Cretaceous period just before the non-bird dinosaurs went extinct, the more fantastic that world becomes," Gates said "Every species in an ecosystem plays a supporting role, keeping the whole network together. There is no way for us to understand what changed in the ecosystem during the mass extinction at the end of the Cretaceous without knowing all the wonderful species that existed before."

Gates told Newsweek that it is not clear how Sue the T. rex ended up next to each other: "We are not even sure if the teeth come form a single shark or many of them. There are lots of scenarios we can speculate upon, but the facts are that Sue the T. rexdied, then landed in a river that was occupied by Galagadon sharks."

galagadon tooth
One of the shark teeth recovered, which scientists say resemble the spaceships in the video game Galaga. Terry Gates

Discovering the shark in the same space as T. rex adds to our understanding of the landscape that would have existed in the region at the time. "Today, carpet sharks, which include bamboo sharks and wobbegongs, mostly live in the waters in southeast Asia and Australia, so it's surprising to find their fossils at the Sue locality," study co-author Eric Gorscak said in a statement. "During the Late Cretaceous the continents continued to drift apart, further isolating dinosaurs and other land animals, and at the same time created the Atlantic and Indian oceans. With occasional seaways connecting these young oceans, we have found fossils of marine life flourishing globally, including Galagadon and its relatives."

Tom Fletcher, a teaching fellow in palaeobiology at the U.K.'s University of Leicester, who was not involved in the study, said people often forget dinosaurs were just part of a much wider ecosystem that existed millions of years ago. "Alongside them were myriad other animals and plants, and every new species discovered improves our understanding of the whole picture," he told Newsweek.

"The discovery of sharks here is fascinating because the Hell Creek Formation was deposited on land, so either these teeth were being transported from another habitat or they may have been swimming up freshwater rivers, much like bull sharks do today. These are not the only sharks discovered at this location, but help demonstrate quite how diverse the shark fauna was at this very special place in space and time."

This article has been updated to include quotes from Terry Gates.