A group of paleontologists just announced it’s found “unambiguous evidence” suggesting that at least some species of Spinosaurus—a genus of theropod dinosaur that lived during the Cretaceous period in what is now North Africa—was fond of swimming. And even though that may not sound like a big deal, it’s apparently monumentally important. One paleontologist behind the study outlining this new evidence even says that this discovery will revolutionize scientists’ understanding of dinosaur biology.

Reuters reported on the finding, which was recently published in the journal, Nature. According to the paper, authored by University of Detroit Mercy paleontologist and anatomist Nizar Ibrahim et al., evidence of a species of Spinosaurus, Spinosaurus aegyptiacus, having a tail in the shape of “an aquatic propulsive structure” has been verified by new fossil findings. The new Spinosaurus fossil evidence was found in the Sahara Desert in southeastern Morocco, although it’s unclear when exactly the fossils were discovered.

New Evidence Suggests Spinosaurus Was a Swimming Shark Eater_1

An illustration of Spinosaurus aegyptiacus’ skeletal system. nature video 

The Spinosaurus is described as “possibly the most enigmatic dinosaur out there” by Ibrahim in the video up top. This is partly because it’s been so hard to collect fossil evidence on the dinosaur genus that lived roughly 95 million years ago. Although paleontologists apparently did have a Spinosaurus skeleton at one point, which was destroyed during World War II.

An illustration of Spinosaurus aegyptiacus. nature video 

What Ibrahim et al. found, specifically, are a series of bones that suggest Spinosaurus aegyptiacus had a giant, fin-like tail that would’ve been perfect for propelling the 16,000 pound dinosaur through the water. And when Ibrahim sent the reconstructed shape of the tail to researchers at Harvard, they verified the effectiveness of the hypothesized tail shape by testing a plastic version of it in water.

The plastic version of Spinosaurus aegyptiacus’ tail. nature video

Ibrahim said that “This discovery overturns decades-old ideas that non-bird dinosaurs were restricted to terrestrial environments,” highlighting the fact that Spinosaurus other physiological features support the idea that it was aquatic. “[I]t had so many adaptations to an aquatic existence—nostrils high on the skull and further back from the tip, flat bottomed-toe bones and claws, dense and thickened bone for buoyancy control, and this newly discovered tail form — that it would have been at least as aquatic as Nile Crocodiles,” Ibrahim added.

An illustration of the fossil evidence found by Ibrahim et al. nature video 

Due to the way Spinosaurus aegyptiacus evolved, it likely had no trouble swimming in rivers and terrorizing fish, and Ibrahim even says it’s possible that this species of Spinosaurus ate sharks. Probably big ones too, considering the fact that this “river monster” was larger than many T. rexes.

What do you think about these Spinosaurus aegyptiacus fossils and the idea that this species of dinosaur loved hunting in the water? Are we going to find a lot more semi-aquatic dinosaurs now, or is this an exception to the rule? Let us know your thoughts in the comments!

Feature image: nature video