Moscow, Jun 16 (IANS): A new "highly unusual" species of the ancient marine reptile called pliosaur from the early Cretaceous period of Russia has been recently described by an international team of researchers.

The new species, described in the journal Current Biology, has got its name from Mongolian mythology.

"The new pliosaur - Luskhan itilensis - has got its name from the Mongolian mythology, where Luus-khan stands for a spirit and master of water, and Itil is the ancient Turkic and Mongolian name for the Volga," said one of the study authors Nikolay Zverkov from Lomonosov Moscow State University.

The pliosaur skeleton was found in 2002 in the Cretaceous deposits (the Hauterivian age of the early Cretaceous Period, about 130 million years ago) on the banks of the Volga River.

Presence of several unique features puzzled the researchers so they had to gather additional data, related to pliosaur morphology, and conduct several additional morphospace analyses.

Contrary to all other advanced pliosaurs, traditionally considered to be unexceptionally macropredators, Luskhan had an elongate skull with slender snout and relatively small teeth.

The latter denotes adjustment to a diet of medium-sized prey: fish and squid.

At the same time, Luskhan showed remarkable resemblance in the form of a skull and snout with representatives of a group of the Cretaceous plesiosaurs (the Polycotylidae family).

"So, the new discovery has shown that ecomorphological diversity of pliosaurs was wider and their evolutionary history is more complicated than previously thought," Zverkov said.