The W1a site was discovered during the summer of 1998. It was found while driving in the rain up to the W3 Main tracksite. Just before the W1 pit the rain stopped and the sun came out. The footwall was covered with tracks that had not been noticed on previous trips. The wet tracks stood out silver against a dark black background. There were so many tracks (all ankylosaur) that it was difficult to pick out an individual trackway. It almost looks as though the trackmakers were just milling around. There were plenty of small tree stumps with radiating root systems amongst the tracks, this combined with the fact that the sediment was pretty fine-grained and very organic indicated a fairly low energy, bog or swamp-like habitat with lots of herbaceous plants. It is possible that the ankylosaurs were in this area for the wealth of plant food.