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The only fossils in the Permian Coconino Sandstone of northern Arizona are abundant fossil trackways. A slab of Coconino Sandstone contains underprints of both vertebrate and invertebrate animals, exposed at two levels separated by a 1-2 mm layer of sand. The underprints on the lower level are deeper and much more distinct than the same trackway exposed on the higher level. The tracks on the upper level were partly infilled by the fine sand, which does not contain clays or other material thatdoi:10.1080/10420949609380129 fatcat:da2u2i47wbhfdougbwbkgedtha