300 million years ago, there were several giant insects due to the high oxygen levels. Among those super-sized creepy crawlies was a giant ancestor of millipedes known as Arthropleura. This thing could grow to be about eight feet long, had armor plating to protect it against predators, and its large mandibles could deliver a nasty bite. Despite its threatening appearance and weaponry, Arthropleura was a herbivore that often foraged along the forest floor. I am thinking of introducing a creature that is similar to Arthropleura in my dinosaur book. I am envisioning it to be more like an armor-plated version of a centipede instead of a millipede.