Walcott, C.D., 1890, The fauna of the Lower Cambrian or Olenellus zone: U.S. Geological Survey Annual Report, 10th, Part 1, p. 509-760. Authors Walcott, C.D. Publication Date 1890 Citation U.S. Geological Survey Annual Report, 10th, Part 1, p. 509-760. State AZ Province CP TR County CN MO Placenames Marble Canyon Keywords Paleontology Invertebrate Cambrian More Keywords Paleontology, Invertebrate, Cambrian, AzGeoBib RefNum 10725