Scientists have discovered fossils of a new species of a large predatory marine reptile in Russia – dating back to 130 million years – which survived the last Jurassic extinction event. Pliosaurs are characterised by a large, 2-metre long skull, enormous teeth and extremely powerful jaws, making them the top predators of oceans during the ‘Age of Dinosaurs’.
They belong to a group of Plesiosaur marine reptiles – the most diverse and one of longest-lived aquatic four-limbed creatures, which possess an unusual body shape not seen in other marine vertebrates with four large flippers, a stiff trunk, and a highly varying neck length.
In a new study published in the journal Current Biology, researchers found a new, exceptionally well-preserved and highly unusual pliosaur from the Cretaceous of Russia (about 130 million years ago). It was found in 2002 on bank of the Volga River in Russia. The skull of the new species, dubbed “Luskhan itilensis”, meaning the Master Spirit from the Volga river, is 1.5 metre in length, indicating a large animal. However, its rostrum is extremely slender, resembling that of fish-eating aquatic animals such as gharials or some species of river dolphins.
“This is the most striking feature, as it suggests that pliosaurs colonised a much wider range of ecological niches than previously assumed,” said Valentin Fischer, lecturer at the Universite de Liege in Belgium. By analysing two new and comprehensive datasets that describe the anatomy and ecomorphology of plesiosaurs with cutting edge techniques, researchers revealed that several evolutionary convergences took place during the evolution of plesiosaurs, notably after an important extinction event at the end of the Jurassic (145 million years ago).
The new findings have also ramifications in the final extinction of pliosaurs, which took place several tens of million years before that of all dinosaurs. The new results suggest that pliosaurs were able to bounce back after the latest Jurassic extinction, but then faced another extinction that would wipe them off the depths of ancient oceans, forever.