GEOLOGICAL HIGHLIGHTS - Myriapod Trail

Near Laggan, on the northeastern shore of Arran, an outcrop of sandstone overlying a worked out coal seem has yielded an outstanding trace fossil. The fossil is a parallel series of imprints, spaced about 0.35m apart and extends for about 5m. It is a trail thought to have been made by a giant myriapod, Arthropleura.

The fossil is from the Limestone Coal Group of the Carboniferous, and is about 350Ma years old. Myriapods are a group of arthropods which include the likes of millipedes and centipedes. Arthropleura would have been nearly two meters in length, flat bodied, had 23 pairs of legs, and most likely lived on the forest floor eating leaf litter.

The image on the left, and the other ones shown below, are of a model of the creature that made the tracks on Arran. The model can be seen in the Hunterian Museum, University of Glasgow, along with a section of the original track

The Carboniferous coal forests would be adjacent to swampy and deltaic areas. It is possible the creature may have wandered out of the forest on to a sandy delta distributary where the trail became preserved.

Images courtesy of Dr Neil Clarke, Hunterian Museum (NB images are reproduced here at original size - there are no larger images linked so do not worry about clicking on the images - to see the model, visit the Hunterian Museum (its free!)).