In the formation of Canadian rock Grande Anse have found some steps of reptiles, the remains of older reptiles found. The oldest fossil reptile known so far belonged to the species Hylonomus lyelli, about 315 million years ago. The current ones, for their part, have been found one kilometer below the layers of footprints, which indicates that these footprints were abandoned by reptiles who lived before the previous ones, between 316 and 319 million years ago.