Fossils of first footsteps on land found in Ontario

[Joeiss]

KINGSTON, ONT. - A set of fossil tracks in a quarry near Kingston, in south eastern Ontario is causing scientists to re-think the timeline of when some creatures made their first brief forays onto land.

Scientists say the fossilized footprints of an ancient, lobster-like arthropod came from an area that was once the shore of a huge sea stretching all the way to Texas.

A team of researchers led by a Canadian geologist think the creatures crawled out of the sea about 500 million years ago – that's tens of millions of years before scientists thought.

The tracks are about 10 centimetres wide on average and the longest one, which is incomplete, is 2.5 metres long.

Dr. Robert MacNaughton of the Geological Survey of Canada is one of the scientists who discovered the tracks.

He and his colleagues from Queen's University in Kingston, the University of Bristol in the United Kingdom and the oil and gas company Nexen Canada of Calgary wrote about the discovery in a recent issue of the journal Geology.

He told CBC Radio's Quirks & Quarks that based on a detailed study of the sandstone bed where the fossils were found, he thinks the creatures came out of the sea onto a barren, rocky land surface.

"We know that animals came out of the sea (here) for the first recorded time," said MacNaughton's colleague, geologist Robert Dalrymple of Queen's University.

MacNaughton said the age of the fossils shows it may have taken animals much longer to migrate from the sea and adapt to life on land than previous models suggest.

The tracks may show when sea life first survived on land, but other scientists say they don't pin down when the full-scale movement of life to land took place.

"They may have had to retreat back to the sea for the rest of their lives and maybe only came out temporarily, sporadically," said David Rudkin of the Royal Ontario Museum.

Woah. This is interesting, IMO.