British palaeontologists believe the fossils are very important

Hip and leg bones unearthed in Portugal have shown for the first time that the same species of dinosaur stalked both continents 150m years ago.

"It's a very important discovery as it gives us some specific information about how wide the Atlantic was at the time the dinosaur lived," Professor Mike Benton told the BBC.

This bone revealed that Europe and North America were connected for much longer than thought

Professor Benton, of Bristol University, said that when the dinosaurs originated 225m years ago, all the continents were close together. But they started to drift apart soon after that.

By 150m years ago, the Atlantic is thought to have been 200 to 300 kilometres wide and far too deep for dinosaurs to cross from one side to the other.

The new discovery shows that significant land bridges between Europe and North America must have remained, even when the new ocean was quite wide. These may have been near Greenland.

The fossil bones are from a dinosaur called Allosaurus fragilis. This eight-metre-long, meat-eating creature is similar to the better known Tyranosaurus rex.

Many Allosaurus fossils have been found in North America, but the Portuegese finds are the first in Europe which can be positively identified as the same species.

They were found over ten years ago in Leiria in west central Portugal, but only studied recently. The bones were found in rocks laid down by a meandering river, close to its estuary.

The find is published in the Journal of the Geological Society.