These tracks were made 300 mya by a giant millipede called Arthropleura.  The yellow ruler is 30cm long, so as you can see, this animal would have been massive. Arthropleura was probably a herbivore, but no conclusive evidence has been found as yet. These photographs were taken on the isle of Arran, Scotland , and this trace fossil is embedded in the rock, just above the tide line. Only two such fossils have been found in the world, one in Arran, and another in Canada . The Canadian fossil however, had the remains of the huge bug at the end of them. It was about two metres in length.

Close up of one side of the tracks