Arthropod appendages from the Weeks Formation Konservat-Lagerstätte: new occurrences of anomalocaridids in the Cambrian of Utah, USA


Authors: Lerosey-Aubril R, Hegna TA, Babcock LE, Bonino E, Kier C

Published in: Bulletin of Geosciences, volume 89, issue 2; pages: 269 - 282; Received 19 April 2013; Accepted in revised form 5 September 2013; Online 4 March 2014

Keywords: Arthropoda, Anomalocarididae, Weeks Formation, Konservat-Lagerstätte, Cambrian, Guzhangian,

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The Guzhangian Weeks Formation (House Range, Utah, USA) contains a virtually unstudied but diverse assemblage of "soft-bodied" organisms. This fauna includes several enigmatic appendages of arthropods that are described in this contribution. Six appendages (two isolated and four paired appendages) are interpreted as frontal appendages of a probably new species of Anomalocaris. They are characterized by a slender morphology, 14 podomeres, ventral spines alternating in size, up to three auxiliary spines per ventral spine, and only two dorsal spines. Another isolated appendage is also tentatively assigned to Anomalocaris, but it exhibits a more robust morphology, a stronger distal tapering, and apparently simple ventral spines, suggesting that it may represent a distinct taxon. These frontal appendages represent the youngest occurrence of anomalocaridids in Laurentia and demonstrate the persistence of older, Burgess Shale-type taxa in the Weeks Formation. An assemblage of four antenniform and six robust and heavily-armed appendages is also described. These are interpreted as the serially arranged, anterior appendages of a single individual of an undetermined arthropod species. This association of three pairs of robust, spiny appendages with two pairs of antenniform structures in a Cambrian arthropod is unique.


ADRAIN, J.M., PETERS, S.E. & WESTROP, S.R. 2009. The Marjuman trilobite Cedarina Lochman: thoracic morphology, systematics, and new species from western Utah and eastern Nevada, USA. Zootaxa 2218, 35-58.

AITKEN, J.D. 1978. Revised models for depositional grand cycles, Cambrian of the southern Rocky Mountains. Bulletin of Canadian Petroleum Geology 26, 515-542.View article

AITKEN, J.D. 1997. Stratigraphy of the Middle Cambrian platformal succession, southern Rocky Mountains. Bulletin of the Geological Survey of Canada 398, 1-322.

BABCOCK, L.E. 2003. Trilobites in Paleozoic predator-prey systems, and their role in reorganization of early Paleozoic ecosystems, 55-92. In KELLEY, P.A., KOWALEWSKI, M. & HANSEN, T.A. (eds) Predator-Prey Interactions in the Fossil Record. Kluwer Academic/Plenum Publishers, New York. View article

BABCOCK, L.E., ROBISON, R.A. & PENG, S.C. 2011. Cambrian stage and series nomenclature of Laurentia and the developing global chronostratigraphic scale. Museum of Northern Arizona Bulletin 67, 12-26.

BEEBE, M.A. 1990. Trilobite faunas and depositional environments of the Weeks Formation (Cambrian), Utah. 103 pp. Ph.D. thesis, University of Kansas, Lawrence, USA.

BOXHALL, G.A. 2004. The evolution of arthropod limbs. Biological Reviews 79, 153-300.

BOXHALL, G.A. & JAUME, D. 2013. Antennules and antennae in the Crustacea, 199-236. In WATLING, L. & THIEL, M. (eds) Natural History of the Crustacea. Volume 1, Functional Morphology and Diversity. Oxford University Press, New York.

BRIGGS, D.E.G. 1976. The arthropod Branchiocaris n. gen., Middle Cambrian, Burgess Shale, British Columbia. Bulletin of the Geological Survey of Canada 264, 1-29.

BRIGGS, D.E.G. 1979. Anomalocaris, the largest known Cambrian arthropod. Palaeontology 22, 631-663.

BRIGGS, D.E.G. & BARTELS, C. 2001. New arthropods from the Lower Devonian Hunsrück Slate (Lower Emsian, Rhenish Massif, Western Germany). Palaeontology 44, 275-303.View article

BRIGGS, D.E.G., LIEBERMAN, B.S., HENDRICKS, J.R., HALGEDAHL, S.L. & JARRARD, R.D. 2008. Middle Cambrian arthropods from Utah. Journal of Paleontology 82, 238-254.View article

BRIGGS, D.E.G. & MOUNT, J.D. 1982. The occurrence of the giant arthropod Anomalocaris in the Lower Cambrian of southern California, and the overall distribution of the genus. Journal of Paleontology 56, 1112-1118.

BRIGGS, D.E.G. & ROBISON, R.A. 1984. Exceptionally preserved nontrilobite arthropods and Anomalocaris from the Middle Cambrian of Utah. University of Kansas Paleontological Contributions 111, 1-23.

BRIGGS, D.E.G., SUTTON, M.D., SIVETER, D.J. & SIVETER, D.J. 2004. A new phyllocarid (Crustacea: Malacostraca) from the Silurian Fossil-Lagerstätte of Herefordshire, UK. Proceedings of the Royal Society B, Biological Sciences 271, 131-138.View article

COLLINS, D. 1996. The “evolution” of Anomalocaris and its classification in the arthropod class Dinocarida (nov.) and order Radiodonta (nov.). Journal of Paleontology 70, 280-293. View article

CONWAY MORRIS, S. & ROBISON, R.A. 1982. The enigmatic medusoid Peytoia and a comparison of some Cambrian biotas. Journal of Paleontology 56, 116-122.

CONWAY MORRIS, S. & ROBISON, R.A. 1988. More soft-bodied animals and algae from the Middle Cambrian of Utah and British Columbia. University of Kansas Paleontological Contributions 122, 1-48.

DALEY, A.C. & BUDD, G.E. 2010. New anomalocaridid appendages from the Burgess Shale, Canada. Palaeontology 53, 721-738.View article

DALEY, A.C., BUDD, G.E. & CARON, J.-B. 2013a. Morphology and systematics of the anomalocaridid arthropod Hurdia from the Middle Cambrian of British Columbia and Utah. Journal of Systematic Palaeontology 11(7), 743-787.View article

DALEY, A.C., PATERSON, J.R., EDGECOMBE, G.D., GARCÍA-BELLIDO, D.C. & JAGO J.B. 2013b. New anatomical information on Anomalocaris from the Cambrian Emu Bay Shale of South Australia and a reassessment of it inferred predatory habits. Paleontology 56(5), 971-990.View article

EDGECOMBE, G.D., GARCÍA-BELLIDO, D.C. & PATERSON, J.R. 2011. A new leanchoiliid megacheiran arthropod from the lower Cambrian Emu Bay Shale, South Australia. Acta Palaeontologica Polonica 56, 385-400.View article

ELRICK, M. & SNIDER, A.C. 2002. Deep-water stratigraphic cyclicity and carbonate mud mound development in the Middle Cambrian Marjum Formation, House Range, Utah, USA. Sedimentology 49, 1021-1047.View article

ENGLISH, A.M. & BABCOCK, L.E. 2010. Census of the Indian Springs Lagerstätte, Poleta Formation (Cambrian), western Nevada, USA. Palaeogeography, Palaeoclimatology, Palaeoecology 295, 236-244.View article

FELGENHAUER, B.E., ABELE, L.G. & FELDER, D.L. 1992. Remipedia, 225-247. In HARRISON, F.W. & HUMES, A.G. (eds) Microscopic Anatomy of Invertebrates. Volume 9, Crustacea. Wiley-Liss, New York, Chichester, Weinheim, Brisbane, Singapore, Toronto.

GARCÍA-BELLIDO, D. & COLLINS, D.H. 2006. A new study of Marrella splendens (Arthropoda, Marrellomorpha) from the Middle Cambrian Burgess Shale, British Columbia, Canada. Canadian Journal of Earth Sciences 43, 721-742.View article

GARCÍA-BELLIDO, D.C. & COLLINS, D. 2007. Reassessment of the genus Leanchoilia (Arthropoda, Arachnomorpha) from the Middle Cambrian Burgess Shale, British Columbia, Canada. Palaeontology 50, 693-709.View article

GUNTHER, L.F. & GUNTHER, V. 1981. Some Middle Cambrian fossils of Utah. Brigham Young University Geology Studies 28, 1-87.

HESSELBO, S.P. 1989. The aglaspidid arthropod Beckwithia from the Cambrian of Utah and Wisconsin. Journal of Paleontology 63, 635-642. View article

HOU, X., BERGSTRÖM, J. & AHLBERG, P. 1995. Anomalocaris and other large animals in the Lower Cambrian Chengjiang Fauna of southwest China. GFF 117, 163-183.View article

LEGG, D.A. & VANNIER, J. 2013. The affinities of the cosmopolitan arthropod Isoxys and its implications for the origin of arthropods. Lethaia 46(4), 540-550.View article

LEROSEY-AUBRIL, R., HEGNA, T.A., KIER, C., BONINO, E., HABERSETZER, J. & CARRÉ, M. 2012. Controls on gut phosphatisation: the trilobites from the Weeks Formation Lagerstätte (Cambrian; Utah). PLoS ONE 7, e32934.View article

LEROSEY-AUBRIL, R., ORTEGA-HERNÁNDEZ, J., KIER, C. & BONINO, E. 2013. Occurrence of the Ordovician-type aglaspidid Tremaglaspis in the Cambrian Weeks Formation (Utah, USA). Geological Magazine 150, 945-951.View article

LIEBERMAN, B.S. 2003. A new soft-bodied fauna: the Pioche Formation of Nevada. Journal of Paleontology 77, 674-690.View article

MCLAUGHLIN, P.A. 1980. Comparative Morphology of Recent Crustacea. 177 pp. W.H. Freeman and Company, San Francisco.

MILLER, J.F., EVANS, K.R. & DATTILO, B.F. 2012. The Great American Carbonate Bank in the miogeocline of western central Utah: tectonic influences on sedimentation, 769-854. In DERBY, J.R., FRITZ, R., LONGACRE, S.A., MORGAN, W. & STERNBACH, C. (eds) The Great American Carbonate Bank: The Geology and Economic Resources of the Cambro-Ordovician Sauk Sequence of Laurentia. American Association of Petroleum Geologists Memoir 98.

MOORE, R.A. & LIEBERMAN, B.S. 2009. Preservation of early and middle Cambrian soft-bodied arthropods from the Pioche Shale, Nevada, USA. Palaeogeography, Palaeoclimatology, Palaeoecology 277, 57-62.View article

NEDIN, C. 1995. The Emu Bay Shale, a Lower Cambrian fossil Lagerstätten, Kangaroo Island, South Australia. Memoirs of the Association of Australasian Palaeontologists 18, 31-40.

PALMER, A.R. 1973. Cambrian trilobites, 3-11. In HALLAM, A. (ed.) Atlas of Palaeobiogeography. Elsevier, Amsterdam & New York.

PENG, S.C., BABCOCK, L.E., ZUO, J.X., LIN, H.L., ZHU, X.J., YANG, X.F., ROBISON, R.A., CHI, Y.P., BAGNOLI, G. & CHEN, Y. 2009. The Global boundary Stratotype Section and Point (GSSP) of the Guzhangian Stage (Cambrian) in the Wuling Mountains, northwestern Hunan, China. Episodes 32, 41-55.

PETERS, S.E. 2003. Evenness, richness and the Cambrian-Paleozoic faunal transition in North America: an assemblage-level perspective. 279 pp. Ph.D. thesis, University of Chicago, Chicago, USA.

RAASCH, G.O. 1939. Cambrian Merostomata. Special Papers of the Geological Society of America 19, 1-146.

RAYMOND, P.E. 1935. Leanchoilia and other Mid-Cambrian Arthropoda. Bulletin of the Museum of Comparative Zoology, Harvard University 76, 205-230.

RESSER, C.E. 1929. New Lower and Middle Cambrian Crustacea. Proceedings of the United States National Museum 76, 1-18. View article

RESSER, C.E. 1931. A new Middle Cambrian merostome crustacean. Proceedings of the United States National Museum 79, article 33, 1-4.View article

REES, M.N. 1986. A fault-controlled trough through a carbonate platform: the Middle Cambrian House Range embayment. Bulletin of the Geological Society of America 97, 1054-1069.View article

ROBISON, R.A. 1991. Middle Cambrian biotic diversity: examples from four Utah lagerstätten, 77-98. In SIMONETTA, A. & CONWAY MORRIS, S. (eds) The Early Evolution of Metazoa and the Significance of Problematic Taxa. Cambridge University Press, Cambridge.

ROBISON, R.A. & BABCOCK, L.E. 2011. Systematics, paleobiology, and taphonomy of some exceptionally preserved trilobites from Cambrian Lagerstätten of Utah. Paleontological Contributions 5, 1-47.

ROWELL, A.J. 1966. Revision of some Cambrian and Ordovician inarticulate brachiopods. University of Kansas Paleontological Contributions 7, 1-36.

SIEBOLD, C.T. VON 1848. Lehrbuch der vergleichenden Anatomie der Wirbellosen Thiere. Erster Theil, 1-679. In SIEBOLD, C.T. VON & STANNIUS, H. (eds) Lehrbuch der vergleichenden Anatomie. Verlag von Veit & Company, Berlin.View article

STRENG, M. & HOLMER, L.E. 2006. New and poorly known acrotretid brachiopods (class Lingulata) from the Cedaria-Crepicephalus zone (late Middle Cambrian) of the Great Basin, USA. Geobios 39, 125-153.View article

UBAGHS, G. & ROBISON, R.A. 1985. A new homoiostelean and a new eocrinoid from the Middle Cambrian of Utah. The University of Kansas Paleontological Contributions 115, 1-24.

WALCOTT, C.D. 1908a. Cambrian Geology and Paleontology, I. No. 1 - Nomenclature of some Cambrian Cordilleran formations. Smithsonian Miscellaneous Collections 53, 1-12.

WALCOTT, C.D. 1908b. Cambrian Geology and Paleontology, I. No. 5 - Cambrian sections of the Cordilleran area. Smithsonian Miscellaneous Collections 53, 167-230.

WALCOTT, C.D. 1911. Cambrian Geology and Paleontology, II. No. 3 - Middle Cambrian holothurians and medusae. Smithsonian Miscellaneous Collections 57, 41-68.

WALCOTT, C.D. 1916a. Cambrian Geology and Paleontology, III. No. 3 - Cambrian trilobites. Smithsonian Miscellaneous Collections 64, 157-258.

WALCOTT, C.D. 1916b. Cambrian Geology and Paleontology, III. No. 5 - Cambrian trilobites. Smithsonian Miscellaneous Collections 64, 303-456.

WHITEAVES, J.F. 1892. Description of a new genus and species of phyllocarid Crustacea from the Middle Cambrian of Mount Stephen, B.C. Canadian Record of Science 5, 205-208.

ZHANG, X.L., SHU, D.G. & ERWIN, D.H. 2007. Cambrian naraoiids (Arthropoda): morphology, ontogeny, systematics, and evolutionary relationships. Journal of Paleontology 81 (No. sp. 68), 1-52. View article