London, Oct 17 : Palaeontologists have found the earliest evidence for the existence of reptiles in Canada.

They say the 315 million-year-old fossilised tracks give an insight into a key milestone in the history of life, when animals left water to live on dry land.

Dr Howard Falcon-Lang from the University of Bristol said the footprints suggested that reptiles evolved between one and three million years earlier than previously thought.

He said the discovery in the fossil-rich sea cliffs at New Brunswick, was pure luck.

“The discovery was pure luck. As I walked along remote sea-cliffs at the end of a long day in the field, I passed a recent rock fall. One large slab of rock was covered with hundreds of fossil footprints! The Sun was low in the sky and I probably wouldn't have seen them if it hadn't been for the shadows,” said Dr Falcon-Lang.

He said the ancient trackway gave an insight into a time when invertebrates were evolving through amphibians to reptiles.

The origin of reptiles, in particular the appearance of eggs protected by a shell, allowed four-legged animals to avoid having to go back into water to lay eggs, heralding life on dry land.

“The evolution of reptiles was one of the most important events in the whole history of life. That paved the way for the diverse ecology that we have on our planet today,” said Dr Falcon-Lang.

Dr Falcon-Lang said the tracks preserved in sandstone were left by reptiles gathering around a watering hole on river plains that were dry for at least part of the year.

Together with colleagues in the UK and Canada, Dr Falcon-Lang has now confirmed that the footprints are older than the skeletons.

“We can be confident the footprints are older than the skeletons,” said Dr Falcon-Lang.

“There were only a few species capable of making prints like this around at the time so we came up with a shortlist of suspects,” added Prof. Mike Benton, also of the University of Bristol, who co-authored the study.

“However, the prints showed that the hands had five fingers and scales, sure evidence they were made by reptiles and not amphibians,” Prof. Benton said.

Prof. Benton said the most likely contender was a lizard-like reptile named Hylonomus lyelli after the 19th Century geologist Sir Charles Lyell.

“The most likely track-maker was the Hylonomus lyelli reptile we know from the slightly later remains at Joggins,” said Dr. Falcon-Lang.

Until now, the oldest evidence for reptiles was thought to be skeletal fossils of the creature found in 1859 by William Dawson.

The results of the study are published in the Journal of the Geological Society of London, reports the BBC. (ANI)