Journal of the Geological Society The Spence Shale Lagerstätte: an important window into Cambrian biodiversity by Julien Kimmig, Luke C. Strotz, Sara R. Kimmig, Sven O. Egenhoff, and Bruce S. Lieberman Journal of the Geological Society Volume 176(4):609-619 July 4, 2019 © 2019 The Author(s). Published by The Geological Society of London

Locations and stratigraphy of the Spence Shale Lagerstätte. Locations and stratigraphy of the Spence Shale Lagerstätte. (a) Map of the western USA showing the location of the Spence Shale. (b) Geological map (based on the USGS state maps for Google Earth Pro) of northern Utah and southern Idaho showing the principal localities within the Spence Shale. AC, Antimony Canyon; BF, Blacksmith Fork; CC, Cataract Canyon; CFC, Calls Fort Canyon; DC, Donation Canyon; EC, Emigration Canyon; HC, Hansen Canyon; HCR, High Creek; MH, Miners Hollow; ON, Oneida Narrows; PP, Promontory Point; SG, Spence Gulch; TMC, Two Mile Canyon. (c) Simplified stratigraphy of the Langston Formation. Julien Kimmig et al. Journal of the Geological Society 2019;176:609-619 © 2019 The Author(s). Published by The Geological Society of London

Sedimentology of the Spence Shale. Sedimentology of the Spence Shale. (a) Lag deposit near base of ‘cycle 3’, consisting of biogenic debris, probably of echinoderm, brachiopod and trilobite remains. It should be noted how bedding bends around the millimetre-size echinoderm bioclasts. The matrix is carbonate-rich siliciclastic mudstone with varying amounts of sub-millimetre carbonate debris. (b) Carbonate-rich siliciclastic mudstone near top of ‘cycle 3’, with several millimetre-long black organic-rich flakes oriented parallel to bedding. Abundant silt-size carbonate particles in the matrix should be noted. Scale bar is 1 mm. Julien Kimmig et al. Journal of the Geological Society 2019;176:609-619 © 2019 The Author(s). Published by The Geological Society of London

Important private collectors. Important private collectors. (a) Lloyd Gunther of Brigham City, UT. (b) Val (right) and Glade (left) Gunther of Brigham City, UT. (c) Paul Jamison of Logan, UT. Julien Kimmig et al. Journal of the Geological Society 2019;176:609-619 © 2019 The Author(s). Published by The Geological Society of London

Selected soft-bodied arthropods from the Spence Shale. Selected soft-bodied arthropods from the Spence Shale. (a) KUMIP 204511 holotype of Meristosoma paradoxum from Miners Hollow, collected by the Gunther family. (b) KUMIP 314041, Mollisonia symmetrica from Miners Hollow, collected by the Gunther family. (c) KUMIP 314038, Waptia cf. W. fieldensis from Cataract Canyon, collected by Val and Glade Gunther. (d) KUMIP 312404, Isoxys sp. from Miners Hollow, collected by Arvid Aase. (e) KUMIP 314036, Tuzoia sp. with burrows under the carapace from Miners Hollow, collected by Phil Reese. (f) KUMIP 204783, Leanchoilia superlata? from Miners Hollow, collected by Val and Glade Gunther. (g) KUMIP 314027, hurdiid H-element from Miners Hollow, collected by the Gunther family. (h) KUMIP 491056, Hurdia sp. appendage from Miners Hollow, collected by Paul Jamison. (i) KUMIP 204777, arthropod appendage from Antimony Canyon, collected by Val Gunther. (j) KUMIP 491904, Dioxycaris argenta from Miners Hollow, collected by the Gunther family (k) KUMIP 357406, holotype of Yohoia utahana from Miners Hollow, collected by Paul Jamison. (l) KUMIP 204784, holotype of Utahcaris orion from Antimony Canyon, collected by Ben Datillo. Scale bars represent 10 mm for (a), (e) and (l) and 5 mm for (b) (c), (d) and (f)–(k). Julien Kimmig et al. Journal of the Geological Society 2019;176:609-619 © 2019 The Author(s). Published by The Geological Society of London

Selected fossils from the Spence Shale. Selected fossils from the Spence Shale. (a) KUMIP 491902 and KUMIP 491903, Vauxia magna from Miners Hollow, collected by Rhiannon LaVine. (b) KUMIP 287449, holotype of Wiwaxia herka from Miners Hollow, collected by Phil Reese and the Gunther family. (c) KUMIP 490902, Wronascolex? ratcliffei from Miners Hollow, collected by Riley Smith. (d) KUMIP 314115, Selkirkia spencei from the Wellsville Mountains, collected by the Gunther family. (e) KUMIP 204370, Eldonia ludwigi from Antimony Canyon, collected by Lloyd and Val Gunther. (f) KUMIP 339907, Sphenoecium wheelerensis from Miners Hollow, collected by the Gunther family. (g) KUMIP 491080, Acinocricus stichus from Miners Hollow, collected by Paul Jamison. (h) KUMIP 490932, Micromitra? sp. from High Creek, with chaetae preserved, collected by Paul Jamison. (i) KUMIP 491805, ‘enrolled’ Amecephalus laticaudum from Miners Hollow, collected by Paul Jamison. (j) KUMIP 491808, Zacanthoides liddelli from High Creek, collected by Paul Jamison (k) KUMIP 491853, Oryctocephalus walcotti from Oneida Narrows, collected by the Gunther family. (l) KUMIP 135150, holotype of Siphusauctum lloydguntheri from Antimony Canyon, collected by Lloyd Gunther. Scale bars represent 5 mm. Julien Kimmig et al. Journal of the Geological Society 2019;176:609-619 © 2019 The Author(s). Published by The Geological Society of London