Media type: E-Article Title: Two new pre-trilobite faunas from western North America Contributor: Signor, Philip W.; McMenamin, Mark A. S.; Gevirtzman, Debra A.; Mount, Jeffrey F. imprint: Springer Science and Business Media LLC, 1983 Published in: Nature Language: English DOI: 10.1038/303415a0 ISSN: 0028-0836; 1476-4687 Keywords: Multidisciplinary Origination: Footnote: