Skip to main content

A new radiodontan oral cone with a unique combination of anatomical features from the early Cambrian Guanshan Lagerstätte, eastern Yunnan, South China

  • Han Zeng (a1) (a2) (a3), Fangchen Zhao (a1), Zongjun Yin (a1) and Maoyan Zhu (a1) (a4)

The radiodontans, including anomalocaridids and their allies, are enigmatic stem-group euarthropods and are the most ancient apex giant predators known from the fossil record. Most studies on their feeding behaviors have emphasized their diverse and abundant raptorial frontal appendages, while the oral cone surrounding the mouth opening in these animals has attracted less attention. At present, three oral cone morphotypes are known, from Anomalocaris Whiteaves, 1892, Peytoia Walcott, 1911, and Hurdia Walcott, 1912, respectively. In this paper, we report on a novel form of radiodontan oral cone from the Guanshan Lagerstätte (Cambrian Series 2, Stage 4) in the Wulongqing Formation, eastern Yunnan, South China. This oral cone is unique in combining features seen in Peytoia/Hurdia and Anomalocaris. It possesses a Peytoia/Hurdia-type ‘tetraradial’ configuration comprising a 32-plate outer ring that consists of four perpendicularly arranged large plates and 28 small plates, in addition to furrowed folds and scale-like nodes on plate surfaces otherwise seen only in Anomalocaris. As an intermediate morphotype, the Guanshan oral cone improves our understanding of the occurrence and morphological disparity of radiodontan oral cones, illuminates future investigations on potentially variable radiodontan feeding mechanisms, and reveals possible evolutionary transformations of these peculiar feeding structures. The resolution of current radiodontan phylogeny would be potentially improved by new knowledge on other body parts apart from frontal appendages in future studies.

Corresponding author
*Corresponding author
Hide All
Aria, C., and Caron, J.-B., 2015, Cephalic and limb anatomy of a new isoxyid from the Burgess Shale and the role of “stem bivalved arthropods” in the disparity of the frontalmost appendage: PLoS ONE, v. 10, p. e0124979.
Briggs, D.E.G., 1979, Anomalocaris, the largest known Cambrian arthropod: Palaeontology, v. 22, p. 631664.
Briggs, D.E.G., and 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, v. 56, p. 11121118.
Briggs, D.E.G., Lieberman, B.S., Hendricks, J.R., Halgedahl, S.L., and Jarrard, R.D., 2008, Middle Cambrian arthropods from Utah: Journal of Paleontology, v. 82, p. 238254.
Budd, G.E., 1998, Stem group arthropods from the lower Cambrian Sirius Passet fauna of North Greenland, in Fortey, R.A., and Thomas, R.H., eds., Arthropod Relationships, Volume 55: Dordrecht, Springer Netherlands, p. 125138.
Chen, J.-Y., 2004, The Dawn of Animal World: Nanjing, Jiangsu Science and Technology Press, 367 p. [In Chinese].
Chen, J.-Y., Ramsköld, L., and Zhou, G.-Q., 1994, Evidence for monophyly and arthropod affinity of Cambrian giant predators: Science, v. 264, p. 13041308.
Chen, J.-Y., Zhou, G.-Q., Zhu, M.-Y., and Yeh, K.-Y., 1996, The Chengjiang Biota: A Unique Window of the Cambrian Explosion: Taizhong, National Museum of Natural Science, 222 p. [In Chinese].
Collins, D., 1996, The “evolution” of Anomalocaris and its classification in the arthropod class Dinocarida (nov.) and order Radiodonta (nov.): Journal of Paleontology, v. 70, p. 280293.
Cong, P.-Y., Ma, X.-Y., Hou, X.-G., Edgecombe, G.D., and Strausfeld, N.J., 2014, Brain structure resolves the segmental affinity of anomalocaridid appendages: Nature, v. 513, p. 538542.
Cong, P.-Y., Daley, A.C., Edgecombe, G.D., Hou, X.-G., and Chen, A.-L., 2016, Morphology of the radiodontan Lyrarapax from the early Cambrian Chengjiang biota: Journal of Paleontology, v. 90, p. 663671.
Conway Morris, S., and Robison, R.A., 1982, The enigmatic medusoid Peytoia and a comparison of some Cambrian biotas: Journal of Paleontology, v. 56, p. 116122.
Daley, A.C., and Bergström, J., 2012, The oral cone of Anomalocaris is not a classic “peytoia”: Naturwissenschaften, v. 99, p. 501504.
Daley, A.C., and Budd, G.E., 2010, New anomalocaridid appendages from the Burgess Shale, Canada: Palaeontology, v. 53, p. 721738.
Daley, A.C., and Edgecombe, G.D., 2014, Morphology of Anomalocaris canadensis from the Burgess Shale: Journal of Paleontology, v. 88, p. 6891.
Daley, A.C., and Legg, D.A., 2015, A morphological and taxonomic appraisal of the oldest anomalocaridid from the lower Cambrian of Poland: Geological Magazine, v. 152, p. 949955.
Daley, A.C., Budd, G.E., Caron, J.-B., Edgecombe, G.D., and Collins, D., 2009, The Burgess Shale anomalocaridid Hurdia and its significance for early euarthropod evolution: Science, v. 323, p. 15971600.
Daley, A.C., Budd, G.E., and 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, v. 11, p. 743787.
Daley, A.C., Paterson, J.R., Edgecombe, G.D., García-Bellido, D.C., and Jago, J.B., 2013b, New anatomical information on Anomalocaris from the Cambrian Emu Bay Shale of South Australia and a reassessment of its inferred predatory habits: Palaeontology, v. 56, p. 971990.
Hagadorn, J.W., 2009, Taking a bite out of Anomalocaris, in Smith, M.R., O’Brien, L.J., and Caron, J.-B., eds., Abstract Volume: International Conference on the Cambrian Explosion—Walcott 2009: Toronto, Burgess Shale Consortium, p. 33–34.
Hagadorn, J.W., 2010, Putting Anomalocaris on a soft-food diet: Geological Society of America Abstracts with Programs, v. 42, no. 5, p. 320.
Hou, X.-G., Bergström, J., and Ahlberg, P., 1995, Anomalocaris and other large animals in the lower Cambrian Chengjiang fauna of southwest China: GFF, v. 117, p. 163183.
Hou, X.-G., Bergström, J., and Jie, Y., 2006, Distinguishing anomalocaridids from arthropods and priapulids: Geological Journal, v. 41, p. 259269.
Hu, S.-X., Zhu, M.-Y., Steiner, M., Luo, H.-L., Zhao, F.-C., and Liu, Q., 2010, Biodiversity and taphonomy of the early Cambrian Guanshan biota, eastern Yunnan: Science China Earth Sciences, v. 53, p. 17651773.
Hu, S.-X., Zhu, M.-Y., Luo, H.-L., Steiner, M., Zhao, F.-C., Li, G.-X., Liu, Q., and Zhang, Z.-F., 2013, The Guanshan Biota: Kunming, Yunnan Science and Technology Press, 204 p. [In Chinese].
Kühl, G., Briggs, D.E.G., and Rust, J., 2009, A great-appendage arthropod with a radial mouth from the Lower Devonian Hunsrück Slate, Germany: Science, v. 323, p. 771773.
Lankester, R.E., 1904, The structure and classification of the Arthropoda: Quarterly Journal of Microscopical Science, v. 47, p. 523582.
Legg, D.A., Sutton, M.D., and Edgecombe, G.D., 2013, Arthropod fossil data increase congruence of morphological and molecular phylogenies: Nature Communications, v. 4, p. 2485 doi: 10.1038/ncomms3485.
Lieberman, B.S., 2003, A new soft-bodied fauna: the Pioche Formation of Nevada: Journal of Paleontology, v. 77, p. 674690.
Lin, H.-L., 2008, Early Cambrian (Chiungchussuan, Tsanglangpuan and Lungwangmiaoan), in Zhou, Z.-Y., and Zhen, Y.-Y., eds., Trilobite Record of China: Beijing, Science Press, p. 3676.
Liu, J.-N., Ou, Q., Han, J., Zhang, Z.-F., He, T.-J., Yao, X.-Y., Fu, D.-J., and Shu, D.-G., 2012, New occurrence of the Cambrian (Stage 4, Series 2) Guanshan Biota in Huize, Yunnan, South China: Bulletin of Geosciences, v. 87, p. 125132.
Luo, H.-L., Li, Y., Hu, S.-X., Fu, X.-P., Hou, S.-G., Liu, X.-Y., Chen, L.-Z., Li, F.-J., Pang, J.-Y., and Liu, Q., 2008, Early Cambrian Malong Fauna and Guanshan Fauna from Eastern Yunnan China: Kunming, Yunnan Science and Techonology Press, 134 p. [In Chinese].
Masiak, M., and Żylińska, A., 1994, Burgess Shale-type fossils in Cambrian sandstones of the Holy Cross Mountains: Acta Palaeontologica Polonica, v. 39, p. 329340.
McHenry, B., and Yates, A., 1993, First report of the enigmatic metazoan Anomalocaris from the southern hemisphere and a trilobite with preserved appendages from the early Cambrian of Kangaroo Island, South Australia: Records of the South Australian Museum, v. 26, p. 7786.
Nedin, C., 1999, Anomalocaris predation on nonmineralized and mineralized trilobites: Geology, v. 27, p. 987990.
Ortega-Hernández, J., 2016, Making sense of ‘lower’ and ‘upper’ stem-group Euarthropoda, with comments on the strict use of the name Arthropoda von Siebold, 1848: Biological Reviews, v. 91, p. 255273.
Smith, M.R., and Caron, J.-B., 2015, Hallucigenia’s head and the pharyngeal armature of early ecdysozoans: Nature, v. 523, p. 7578.
Steiner, M., Zhu, M., Zhao, Y., and Erdtmann, B.-D., 2005, Lower Cambrian Burgess Shale-type fossil associations of South China: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 220, p. 129152.
Van Roy, P., and Briggs, D.E.G., 2011, A giant Ordovician anomalocaridid: Nature, v. 473, p. 510513.
Van Roy, P., Daley, A.C., and Briggs, D.E.G., 2015, Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps: Nature, v. 522, p. 7780.
Vinther, J., Stein, M., Longrich, N.R., and Harper, D.A.T., 2014, A suspension-feeding anomalocarid from the early Cambrian: Nature, v. 507, p. 496499.
Vinther, J., Porras, L., Young, F.J., Budd, G.E., and Edgecombe, G.D., 2016, The mouth apparatus of the Cambrian gilled lobopodian Pambdelurion whittingtoni : Palaeontology, v. 59, p. 841849.
Walcott, C.D., 1911, Cambrian geology and paleontology II. No. 3. Middle Cambrian holothurians and medusae: Smithsonian Miscellaneous Collections, v. 57, p. 4168.
Walcott, C.D., 1912, Cambrian geology and paleontology II. No. 6. Middle Cambrian Branchiopoda, Malacostraca, Trilobita and Merostomata: Smithsonian Miscellaneous Collections, v. 57, p. 145228.
Wang, Y.-Y., Huang, D.-Y., and Hu, S.-X., 2013, New anomalocaridid frontal appendages from the Guanshan biota, eastern Yunnan: Chinese Science Bulletin, v. 58, p. 39373942.
Whiteaves, J.F., 1892, Description of a new genus and species of phyllocarid crustacea from the middle Cambrian of Mount Stephen, BC: The Canadian Record of Science, v. 5, p. 205208.
Whittington, H.B., and Briggs, D.E.G., 1985, The largest Cambrian animal, Anomalocaris, Burgess Shale, British Columbia: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, v. 309, p. 569609.
Yang, J., Ortega-Hernández, J., Gerber, S., Butterfield, N.J., Hou, J.-B., Lan, T., and Zhang, X.-G., 2015, A superarmored lobopodian from the Cambrian of China and early disparity in the evolution of Onychophora: Proceedings of the National Academy of Sciences, v. 112, p. 86788683.
Zeng, H., Zhao, F.-C., Yin, Z.-J., and Zhu, M.-Y., 2017, Morphology of diverse radiodontan head sclerites from the early Cambrian Chengjiang Lagerstätte, south-west China: Journal of Systematic Palaeontology, p. 137. doi: 10.1080/14772019.2016.1263685.
Zhao, F.-C., Hu, S.-X., Caron, J.-B., Zhu, M.-Y., Yin, Z.-J., and Lu, M., 2012, Spatial variation in the diversity and composition of the lower Cambrian (Series 2, Stage 3) Chengjiang Biota, Southwest China: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 346/347, p. 5465.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Paleontology
  • ISSN: 0022-3360
  • EISSN: 1937-2337
  • URL: /core/journals/journal-of-paleontology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *