Berlin, Dec 17 (PTI) Scientists have revealed thatplesiosaur, an unusual underwater reptile that lived 201million years ago, was a powerful swimmer.
Numerous fossils documented a global distribution of thegroup during the Jurassic and Cretaceous periods.
Whereas sea turtles mainly use their strong forelimbs forpropulsion, the plesiosaurs moved all four limbs together,resulting in powerful thrust.
"I could not believe that there was a plesiosaur fromthe Triassic, given that these animals had been studied bypaleontologist for nearly 300 years, and never was there oneolder than Jurassic," said Martin Sander from the Universityof Bonn in Germany.
The scientists bestowed the name Rhaeticosaurus mertension the unique fossil.
According to the findings published in the journalScience Advances, the reconstructed length of the skeleton is237 centimetres.
These long extinct "paddle saurians" propelled themselvesthrough the World's oceans by employing "underwater flight" –similar to sea turtles and penguins.
Instead of laboriously pushing the water out of the waywith their paddles, plesiosaurs were gliding elegantly alongwith limbs modified to underwater wings.
Their small head was placed on a long, streamlined neck.
The stout body contained strong muscles keeping those wings inmotion.
Compared to the other marine reptiles, the tail was shortbecause it was only used for steering. This evolutionarydesign was very successful, but curiously it did not evolveagain after the extinction of the plesiosaurs, Sander said.
For the study, the researchers studied a bone sample.
Based on the growth marks in the bones, the researchersrecognised that species was a fast growing youngster.
They compared the thin sections with those from youngplesiosaurs from the Jurassic and Cretacous.
"At the end of the Cretaceous, a meteorite impacttogether with volcanic eruptions lead to an ecosystemcollapse, of which plesiosaurs were prominent victims," Sandersaid. PTI SNE MHNSNE.
This is unedited, unformatted feed from the Press Trust of India wire.