While the land was dominated by dinosaurs, the oceans were the realm of pliosaurs. These giant carnivores were some of the top predators in the seas some 130 million years ago, and now a new massive species has been discovered in Russia.
Pliosaurs were large marine reptiles, belonging to the more slender-necked group of creatures known as plesiosaurs. While the small head and more graceful form of the plesiosaurs suggest they were more adept at hunting fish, the squat body, large head, and mouth full of teeth of the pliosaurs imply that they chomped on more substantial prey.
It is thought that while some pliosaurs probably did snack on fish, others were more likely feeding on sharks, ichthyosaurs, dinosaurs, and even other plesiosaurs. Some species of these marine creatures grew to impressive sizes, with one of the largest to date dug out of the cliffs on the aptly named Jurassic Coast in England and measuring in at 16 meters (52 feet) long, including a bone-crunching skull of 2.4 meters (8 feet).
This latest discovery is a not quite as big as that, but it's still no shrinking violet. The skull of the beast, measuring 1.5 meters (5 feet) long, was first discovered on the banks of the Volga River, near the city of Ulyanovsk, in 2002, but has remained undescribed until now. In a new study published in Current Biology, the latest beastie is named Luskhan itilensis, or Master Spirit from the Volga River. Based on the size of the skull, the researchers suspect that the pliosaur would have reached the length of a bus.
Interestingly, the slender snout of the newly described reptile looks incredibly similar to another group of pliosaurs known as the polycotylids. But by analyzing the family tree of the creatures, the researchers determined that this feature evolved repeatedly among the group of marine reptiles between 200 and 146 million years ago, in a process known as convergent evolution.
This elongated nose of the new species suggests that while its more robust relatives may have been snacking on dinosaurs, this species may have returned to a more fishy diet. “This is the most striking feature, as it suggests that pliosaurs colonized a much wider range of ecological niches than previously assumed,” explains lead author Valentin Fischer, from the Université de Liège, in a statement.