In 2021, scientists identified a new species of mosasaur with the discovery of a Cretaceous-period jaw with unusual teeth in a Moroccan mine. There’s just one problem—the corpses can be fake.

Canadian researchers have raised doubts about the authenticity of the fossil used to identify and describe a new species of extinct marine reptile, Xenodens calminechariin 2021. Their analysis, detailed on December 16 study published in The Anatomical Recordhighlights the inconsistencies within the previous research and called for a new CT scan of the jaw to confirm its validity.

If their suspicions are proven true, it “must be established in the published literature that this is a fake,” Henry Sharpe of the University of Alberta, who led the new study, said. Live Science.

Our rebuttal to “Xenodens” is now published open-access in The Anatomical Record: this rare “shark-toothed” mosasaur is likely a fake and nondiagnostic (🧵) pic.twitter.com/9s1UWMYJaw

– Hank Sharpe (@Paleoartologist) December 17, 2024

Mosasaurs large sea lizards and one of the main predators of the oceans during the Cretaceous period (145.5 million to 66 million years ago), with some individuals reaching up to 56 feet (17 meters) the height. Researchers from a 2021 study partly based their identification of a new mosasaur species on four sharp teeth found in an incomplete jawbone, dated between 72.1 and 66 million years ago. years ago, and unearthed a Moroccan phosphate mine.

“The new mosasaurid exhibits a dental battery (dental arrangement) with many small, short, bladelike teeth packed together to form a saw-like cutting edge,” the researchers, led by Nicholas R. Longrich from the University of Bath, wrote the 2021 study. They claim that this is the first arrangement of teeth discovered in tetrapods (four-legged vertebrates), and this hypothesis prompted Sharpe and his colleagues to take a closer look.

Two of the living teeth of the alleged X. calminechari The jaw sits within a tooth socket—a feature that contrasts with most other known mosasaur teeth and jaw arrangements, where each tooth grows in its own socket. Mosasaur tooth sockets were made from the bone of individual teeth, as opposed to jawbone, explained Michael Caldwell of the University of Alberta, who also contributed to the new study. That means each tooth must have its own socket.

“Every time one of these teeth gets resorbed and comes out, there’s a big hole left. And that’s because the next tooth comes into that hole to rebuild all the tissue so that it firmly anchored in the jaw,” he told Live Science. In addition, Sharpe’s team suggested the presence of “possible adhesive material” and argued that the particular overlap of a type of tissue in the two teeth are unusual and may indicate forgery, according to the study.

Apart from the teeth themselves, the discovery of the jawbone in the Khouribga province of Morocco took place under potentially dubious circumstances, as the fossil was “obtained nonscientifically (without technical supervision) from an area in Morocco that could yield a lot of manipulated or fake specimens,” they wrote in the study.

The researchers ultimately suggested that the teeth and jaws may belong to two different creatures, although CT scans of the remains will resolve any doubts. It remains to be seen whether researchers will be able to apply this technique to X. calminechari fossil—or convince others to do so—in the near future. For now, keep on the lookout if you come across citations of a new mosasaur with weird teeth!