Multiple Origins Underwater: How Mosasaurs Evolved Aquatic Adaptations More Than Once
When people think of mosasaurs, they often imagine massive sea reptiles with powerful tails, streamlined bodies, and razor-sharp Mosasaurus teeth. These apex predators ruled the oceans of the Late Cretaceous, hunting fish, ammonites, and even other marine reptiles. But recent studies suggest their journey into aquatic life may not have been a single evolutionary leap. Instead, mosasaurs could have developed their marine adaptations more than once, independently, across different lineages. What Are Mosasaurs? Mosasaurs were marine reptiles that thrived around 98–66 million years ago. Related to monitor lizards and snakes, they transitioned from land-dwelling ancestors to fully aquatic hunters. Fossil evidence, including skulls, vertebrae, and Mosasaurus teeth, highlights their powerful bite force and adaptations for a carnivorous diet. For decades, paleontologists believed mosasaurs evolved their aquatic body plan once, early in their history. However, new research paints a more complex...