London, Dec 21 (IANS): A pre-Jurassic era fossil of a carnivorous marine reptile has been found on a beach in south Wales.

Jonathan Bow was walking on the shoreline in Penarth area when he stumbled upon the ichthyosaur fossil, media reports said.

"Something this large and complete is a once in a lifetime find," Bow, a computer programmer in Swansea, was quoted as saying in a BBC report.

Other fossils from the Jurassic period have been unearthed in the area.

It took Bow and his brother one whole day to get the skeletal fossil in about 60 kg of stone.

Ichthyosaurs or fish lizards were predatory reptiles that swam the oceans when dinosaurs walked on land.

These marine reptiles appeared on the earth around 250 million years ago, 25 million years earlier than dinosaurs, and disappeared again earlier.

They were replaced by plesiosaurs, a long necked marine reptile.

Other ichthyosaur skulls and paddles were found in Wales earlier but were not fully articulated specimen.