The Saltwater Secret of the Dinosaur-Eating Crocodile

The ancient terror crocodile, Deinosuchus, was a fearsome predator that roamed North America around 82 to 75 million years ago. This giant reptile had a body nearly as long as a bus and teeth the size of bananas. It was known for its wide, long skull with a unique, bulbous lump, unlike any other crocodilian. Fossil evidence suggests that Deinosuchus hunted or scavenged dinosaurs, leaving its marks on Cretaceous bones. Deinosuchus was often mistakenly called a "greater alligator" and was thought to be closely related to modern alligators. However, new research has revealed a different story. By studying fossils and DNA from living crocodilians, scientists have discovered that Deinosuchus belonged to a different branch of the crocodilian family tree. Unlike alligators, Deinosuchus had salt glands, which allowed it to tolerate saltwater. This trait was crucial for its survival and success. The ability to handle saltwater would have been a significant advantage for Deinosuchus. It could navigate the Western Interior Seaway, which divided North America during a period of global sea level rise. This allowed Deinosuchus to spread across the continent, inhabiting coastal marshes on both sides of the ancient inland sea and along the Atlantic coast. This adaptability helped Deinosuchus become a dominant predator in marshy ecosystems, feeding on a variety of large prey. The new findings about Deinosuchus provide insights into how some species adapted to environmental changes while others went extinct. The revised family tree of crocodilians shows that saltwater tolerance is an ancient trait, lost in alligatoroids over time. This trait would have been beneficial during climate shifts, allowing crocodilians to be more opportunistic and resilient. Deinosuchus, with its massive size and saltwater tolerance, was a formidable predator that left its mark on the ecosystems it inhabited. The study also highlights the importance of combining molecular data with morphological analysis to understand the evolution of species. By incorporating data from extinct crocodilians, researchers were able to connect species that were not previously recognized as related. This approach provides a clearer picture of how Deinosuchus evolved and its role in the ecosystem. The research underscores the ecological flexibility of both extinct and living crocodilians, showing that giant crocodilians have evolved independently in aquatic environments multiple times over the past 120 million years.