Shale,
Park Hills, St. Francois County, Missouri, USA
Sediment-filled worm burrows within the Upper Cambrian Davis Shale at Park Hills, MO. Iron oxides within some burrows mimic the appearance of worms. These burrows are infrequently intersected by trilobite burrows, documenting some of the earliest predatory activity seen in the fossil record (see Selly,T., Huntley, J.W., Shelton, K.L., ...
© Kevin Shelton