We get a similar (or possibly the same, no idea) species here in OK. It's some sort of millipede for sure, but I couldn't tell you anything specific about them other than the fact that they are flat bodied like the prehistoric Arthropleura and super tiny. They have nice color on the top side as well. I've seen them in reds, oranges, and pinks. Though I suppose they could all be different species just as easily.