Journal of Paleontology, 92(3), 2018, p. 442–458 Copyright © 2018, The Paleontological Society. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/ licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. 0022-3360/18/0088-0906 doi: 10.1017/jpa.2017.155 Buenellus chilhoweensis n. sp. from the Murray Shale (lower Cambrian Chilhowee Group) of Tennessee, the oldest known trilobite from the Iapetan margin of Laurentia Mark Webster,1 and Steven J. Hageman2 1Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 〈
[email protected]〉 2Department of Geology, Appalachian State University, Boone, North Carolina 28608, USA 〈
[email protected]〉 Abstract.—The Ediacaran to lower Cambrian Chilhowee Group of the southern and central Appalachians records the rift-to-drift transition of the newly formed Iapetan margin of Laurentia. Body fossils are rare within the Chilhowee Group, and correlations are based almost exclusively on lithological similarities. A critical review of previous work highlights the relatively weak biostratigraphic and radiometric age constraints on the various units within the succession. Herein, we document a newly discovered fossil-bearing locality within the Murray Shale (upper Chilhowee Group) on Chilhowee Mountain, eastern Tennessee, and formally describe a nevadioid trilobite, Buenellus chilhoweensis n. sp., from that site. This trilobite indicates that the Murray Shale is of Montezuman age (provisional Cambrian Stage 3), which is older than the Dyeran (provisional late Stage 3 to early Stage 4) age suggested by the historical (mis)identification of “Olenellus sp.” from within the unit as reported by workers more than a century ago.