980
Journal of Paleontology
(Table 1). In most of these cases, G. marina traces are largely or entirely confined to the area of the disc, with the highest degree of sinuosity and greatest number of self-crossings at the middle and outer rings (Wang et al., 2004). This distinctive pattern suggests a scavenging relationship between the G. marina tra- cemaker, presumably a worm-like animal (Yang, 1994; Wang et al., 2004), and carcasses of P. guizhouensis, thereby forming a distinctive example of thanatocoenosis. No other evidence of scavenging has been detected for specimens of P. guizhouensis.
Associations of uncertain paleoecological significance.—In addition to the associations mentioned above, some specimens of P. guizhouenesis are associated with individual complete brachiopods with preserved pedicles, monoplacophorans, and hyolithids (Table 1; Fig. 7.2, 7.4). Because the associated spe- cimens are small relative to the discs and do not show a dis- tinctive spatial pattern, it is uncertain whether the associations represent additional examples of symbiosis as opposed to attachment to discs of dead individuals of Eldonia on the sea floor.
Discussion
Complex associations between the eldonioid Pararotadiscus guizhouensis and other fossils in the Kaili Biota provide an opportunity to gather important additional information about organismal interactions during the Cambrian. Details of these associations, as documented herein, reflect: (1) relationships between living organisms, (2) relationships between living and dead organisms, and (3) juxtaposition that arises purely from mixing during burial. Thus, examples in our study would seem to represent biocoenoses, thanatocoenoses, and taphocoenoses. Notably, the particular examples of symbioses and scavenging behavior documented herein are unique among Cambrian bio- tas. As such, they contribute to a growing body of evidence that points to a greater degree of ecological complexity among Cambrian marine communities than previously suspected. This view is supported by recent studies that document the attach- ment of specimens of the linguloid brachiopod Diandongia to other animals in the Chengjiang Biota (Z.F. Zhang et al., 2003, 2010) and an ecological association between the brachiopod Nisusia and the annelid Wiwaxia in the Burgess Shale (Topper et al., 2014, 2017). Further studies of the Kaili Biota hold the promise of yielding additional insights concerning the ecology of the Cambrian biosphere.
Acknowledgments
This study was supported by grants from the Major State Basic Research Development Program of China (2015FY310-100) and the National Natural Science Foundation of China (41330101, 41772021, 41702022, 41662001). We are grateful to M. Zhu and H. Sun (Nanjing Institute of Geology and Palaeontology, Chinese Academy of Science, Nanjing, China), Z. Zhang (Northwestern University), and R. Parsley (Tulane University) for linguistic revision.
References
Briggs, D.E.G., Erwin, D.H., and Collier, F.J., 1994, The Fossils of the Burgess Shale: Washington/London, Smithsonian Institution Press, 238 p.
Caron, J.B., and Jackson, D.A., 2008, Paleoecology of the Greater Phyllopod Bed community, Burgess Shale: Palaeogeography, Palaeoclimatology, Palaeocology, v. 258, p. 222–256.
Chen, J.Y., 2004, The Dawn of Animal World: Nanjing, Jiangsu Science and Technology Press, 366 p. [in Chinese].
Chen, J.Y., and Zhou, G.Q., 1997, Biology of the Chengjiang fauna: Bulletin of the National Museum of Science, v. 10, p. 11–106.
Chen, J.Y., Hou, X.G., and Lu, H.Z., 1989, Early Cambrian netted scale-bearing worm-like sea animal:ActaPalaeontologicaSinica, v. 29, p. 57–71. [inChinese].
Chen, J.Y., Zhou, G.Q., and Ramsköld, L., 1995, A new Early Cambrian medusiform onychophoran-like animal Paucipodia gen. nov. from the Chengjiang fauna, China: Transcations of the Royal Society of Edinburgh, Earth Science, v. 85, p. 275–282.
Chen, J.Y., Zhou, G.Q., Zhu, M.Y., and Ye, G.Y., 1996, The Chengjiang Biota: A Unique Window of the Cambrian Explosion: Taichung, National Museum of Natural Science, 222 p. [in Chinese].
Cheng, X., Fu, X.P., and Zhao, Y.L., 2009, A preliminary study of the medu- siform fossils (Pararotadicus) associating with brachiopods from the Cambian Kaili Biota, Jianhe, Guizhou: Acta Palaeontologica Sinica, v. 48, p. 672–680. [in Chinese].
Conway Morris, S., and Robison, R.A., 1986, Middle Cambrian priapulids and other soft-bodied fossils from Utah and Spain: University of Kansas Paleontological Contributions, v. 117, p. 1–22.
Conway Morris, S., and Robison, R.A., 1988, More soft-bodied animals and algae from the Middle Cambrian of Utah and British Columbia: University of Kansas Paleontological Contributions, v. 122, p. 1–48.
Dzik, J., Zhao, Y.L., and Zhu, M.Y., 1997, Mode of life of the Middle Cambrian eldonioid lophophorate Rotadiscus: Palaeontology, v. 40, p. 385–396.
Emmons, E., 1844, The Taconic System: Based on Observation in New York. Massachusetts, Maine, Vermont, and Rhode Island: Albany, New York, Caroll and Cook, 68 p.
Gaines, R.R., Briggs, D.E.G., and Zhao, Y.L., 2008, Burgess Shale-type deposits share a common mode of fossilization: Geology, v. 36, p. 755–758.
Hou, X.G.,Bergström,J.,Wang,H.F.,Feng,X.H.,and Chen,A.L.,1999,The Chengjiang Fauna: Exceptionally Well Preserved Animals from 530 Million Years Ago: Kunming, Yunnan Scientific Technology Press, 191 p. [in Chinese].
Hou, X.G., Aldridge, R.J., Bergstrom, J., Siveter, D.J, Siveter, D.J, and Feng, X. H., 2003, The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life: Malden, Massachusetts, Wiley-Blackwell Publishing, 233 p.
Ivantsov, A.Y., Zhuravlev, A.Y., Leguta, A.V., Krassilov, V.A., Melnikova, L. M., and Ushatinskaya, G.T., 2005, Palaeocology of the Early Cambrian Sinsk biota from the Siberian platform: Palaeogeography, Palaeoclimatol- ogy, Palaeoecology, v. 220, p. 69–88.
Jin, Y.G., Hou, X.G., and Wang, H.Y., 1993, Lower Cambrian pediculate lin- gulids from Yunnan, China: Journal of Paleontology, v. 67, p. 788–798.
Lu, Y.H., Qian, Y.Y., and Zhu, Z.L, 1963, Trilobite: Beijing, Science Press, 231 p. [in Chinese].
Matthew, G.F., 1899, Studies on Cambrian faunas, no. 3: Upper Cambrian fauna of Mt. Stephen, British Columbia: Transactions of the Royal Society of Canada, ser. 2, v. 5, p. 39–66.
Mao, J.R., Zhao, Y.L., Yu, P., and Qian, Y., 1992, Some Middle Cambrian hyolithids from Taijiang, Guizhou: Acta Micropalaeontologica Sinica, v. 9, p. 257–265. [in Chinese with English abstract].
Robison, R.A., and Sprinkle, J., 1969, Ctenocystoidea: new class of primitive echinoderms: Science, v. 166, 3912, p. 1512–1514.
Runnegar, B., and Jell, P.A., 1976, Australian Middle Cambrian molluscs and their bearing on early molluscan evolution: Alcheringa, v. 1, p. 109–138.
Schroeder, N.I., Paterson, J.R., and Brock, G.A., 2018, Eldonioids with asso- ciated trace fossils from the lower Cambrian Emu Bay Shale Konservat- Lagerstätte of South Australia: Journal of Paleontology, v. 92, p. 80–86.
Sun, W.G., and Hou, X.G., 1987, Early Cambrian medusae from Chengjiang, Yunnan, China: Acta Palaeontologica Sinica, v. 28, p. 257–271. [in Chinese].
Topper, T.P., Holmer, L.E., and Caron, J.B., 2014, Brachiopods hitching a ride: an early case of commensalism in the middle Cambrian Burgess Shale: Scientific Reports, v. 4, p. 6704.
Topper, T.P., Strotz, L.C., Skovsted, C.B., and Holmer., L.E., 2017, Do bra- chiopods show substrate-related phenotypic variation? A case study from the Burgess Shale: Palaeontology, v. 60, p. 269–279.
Walcott, C.D., 1911, Middle Cambrian holothurians and Medusae. Cambrian Geology and Palaeontology II: Smithsonian Miscellaneous Collections, v. 57, p. 41–68.
Wang, Y., Zhao, Y.L., Lin, J.P., and Wang, P.L., 2004, Relationship between trace fossils Gordia and medusiform fossils Pararotadiscus from the Kaili
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172 |
Page 173 |
Page 174 |
Page 175 |
Page 176 |
Page 177 |
Page 178 |
Page 179 |
Page 180 |
Page 181 |
Page 182 |
Page 183 |
Page 184 |
Page 185 |
Page 186 |
Page 187 |
Page 188 |
Page 189 |
Page 190
