A sea-dwelling reptiles the size of a bus is determined for the first time from a huge fossil found in Russia.
Scientists say that it is “fundamentally changed” our understanding of the evolution of plesiosaurs that lived in the sea when dinosaurs roamed Earth about 130 million years ago.
Plesiosaurs possess an unusual form of the body not seen in other marine vertebrates, with four large flippers, a stiff hull, and a highly variable neck length.
Pliosaurs were a type of plesiosaur, which is characterized by a large, two metre-long skull, huge teeth and very powerful jaws, making them the top ocean predators during the dinosaur age.
An international research team described in the journal Current Biology a new, “exceptionally well preserved” and highly unusual pliosaur of about 130 million years ago.
It was found in the Autumn of 2002 on the right bank of the Volga River, close to the city of Ulyanovsk, by Gleb Uspensky, Ulyanovsk State University, one of the co-authors of the paper.
The species is called Luskhan itilensis – the significance of the “master-spirit of the Volga”.
His skull is 1.5 metres in length, indicating that it was a very large animal, but the snout (beak) is extremely slender, resembling that of a fish-eating invertebrate animals like gharials, or some species of dolphins.
Study lead author Doctor Valentin Fischer, a lecturer at the University of Liège in Belgium, said: “This is the most striking, because it suggests that pliosaurs colonized a much wider range of ecological niches than previously assumed.”
He said the findings have implications with regard to the final extinction of pliosaurs, which took place a few tens of million years for that of all dinosaurs, with the exception of some bird lines.
Dr. Discher added: “The new results suggest that pliosaurs were able to bounce back after the last Jurassic extinction, but then is faced with another extinction and that would be – in this time – wipe them from the depths of the ancient oceans, forever.”