Arthropleura had a flat, segmented body with bumpy ornamentation. It was an upper Carboniferous relative of centipedes and millipedes, but was not one of the two itself. It’s size may be attributed to two environmental conditions, a lack of terrestrial predators, and the immense concentration of oxygen in the atmosphere (which is why we can’t have giant bugs anymore, so those of you fearing the giant ant takeover, don’t worry, it can’t happen.) It is mostly known from fossil segments, but rare complete specimes have been found, and so have it’s long, sinuous trackways. It had many segmented legs (the legs had many segments,) which sets it apart from centipedes and millipedes. It has been found in OH, PA, IL, KA, NM, Canada, and Europe.