a slab of gray rock with several raised tube shapes on it.
Trace fossils, including worm burrows and trilobite feeding traces (Cruziana) in a block of Bright Angel Shale, Grand Canyon National Park, Arizona.
Permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this website. Digital assets without any copyright restrictions are public domain.
NPS Photo by Cassi Knight, Paleontology Guest Scientist