Ancient sea turtle fossils found in Vic

They're known for being slow but a very old turtle has moved Australian science forward in leaps and bounds.

In fact, the fossilised remains of two five-million-year-old sea turtles have been found at Melbourne's Beaumaris beach, with experts saying the discovery has redefined science in the field.

Museum Victoria senior curator Dr Erich Fitzgerald says the fossils, a shell bone and jaw, highlight the value of the rich Beaumaris site.

"These fossils are the first discovered and only known evidence of the evolution of sea turtles in Australia after the extinction of the dinosaurs 66 million years ago," he said in a statement issued by the museum on Friday.

Dr Fitzgerald said Beaumaris was the key to unlocking the history of Australia's lost marine fauna, and there was "simply nowhere else like it in Australia".

The fossils indicate the ancient turtles were small, less than 60cm long.

The museum says they reveal an ancient branch of the Cheloniidae family, which evolved before most sea turtles currently in Australia.