Scientists have identified a new mosasaur species with a strikingly unusual set of teeth, each blade running along the full length of the tooth and oriented upward much like a Phillips screwdriver. The discovery comes from research associated with the University of Bath and adds a remarkable twist to our understanding of predatory marine reptiles from the late Cretaceous period.
The species, tentatively named Stelladens mysteryfound, hails from ancient Moroccan sediment beds. It lived about 100 million years ago and was roughly twice the size of today’s dolphins. Like other mosasaurs, Stelladens mysteryfound belongs to a group of predatory sea lizards related to modern monitor lizards. These reptilian hunters dominated the oceans before their extinction at the end of the Cretaceous, about 66 million years ago.
The teeth of Stelladens mysteryfound are a standout feature. Rather than the typical two blade-like serrations seen on most mosasaurs, these teeth carry long blade-like protrusions that give the impression of a Phillips screwdriver when viewed from the side. The blades appear to extend along the full length of the tooth, suggesting a specialized feeding strategy that would set this species apart from its relatives. Researchers note that the teeth were small yet robust, with tips that show signs of erosion. This morphology implies a diet that did not rely on soft-bodied prey, and it seems unlikely that the teeth were designed for crushing heavily armored prey such as oysters or sea urchins. The team has ruled out simple pathology or random mutation as an explanation for this unusual dental design, reinforcing the conclusion that Stelladens mysteryfound used its teeth in a distinctive way during hunting and processing prey. The exact function remains a subject of scientific discussion and study.
To date, teeth shapes in mosasaurs have often correlated with feeding habits and ecological roles. Yet Stelladens mysteryfound challenges existing interpretations and suggests that mosasaurs explored a broader range of predatory adaptations than previously recognized. The discovery prompts paleontologists to reassess how tooth morphology relates to prey choices in marine reptiles and to consider how dental innovations could arise in response to changing marine ecosystems during the late Cretaceous. The Moroccan fossil beds continue to yield insights into a time when mosasaurs ruled deep-sea environments, competing with other predators and carving out specialized niches in oceanic food webs.
In the broader picture, mosasaurs arose roughly 100 million years ago and disappeared alongside the dinosaurs at the end of the Cretaceous. Each new fossil find adds depth to the story of these formidable marine reptiles and sharpens the questions scientists ask about ancient feeding strategies and dental evolution. The discovery of Stelladens mysteryfound is a reminder that even well-studied groups can still harbor surprises that reshape how scientists understand ancient life in the seas.
Note: The description of this species and its dental features reflects ongoing research and interpretation within the field of paleontology. Further analyses and additional fossil material are expected to clarify how Stelladens mysteryfound fed and interacted within its ancient ecosystem.