A symphylan! These are a secretive group of myriapods, a sister group to millipedes and centipedes. They are usually quite small and hard to find.

Beautiful cover of the latest issue of the Science Advances journal, featuring a fossil of Arthropleura, the largest arthropod of all time.

https://www.science.org/toc/sciadv/10/41

Symphyla are tiny, fast-moving, unpigmented relatives of centipedes and millipedes, which feed on decaying organic matter and plant roots.