8


Journal of Paleontology 90(1):1–9


early middle Cambrian succession of Kyrgyzstan, but it has not been studied in detail (cf. Teslenko et al., 1983). Two other reefs consisting of siliceous sponges of unknown affinity and microbes have been reported, from the Cambrian Series 3 (Drumian) of the Daegi Formation, Taebaeksan Basin, Korea (Hong et al., 2012), and the Furongian (Jiangshanian) of the Chaomidian Formation, Shandong Province, China (Lee et al., 2014a). Both siliceous sponges are unidentifiable from outcrops and only identifiable under the microscope, causing problems for identification. The characteristics of spicules and spicule networks of these sponges, however, suggest that both examples most likely belong to class Demospongia (Rigby, 1983; Hooper andVan Soest, 2002; Pisera, 2002). On the other hand, some of the sponges in the Daegi Formation (an eastward extension of the Zhangxia Formation) showing rectangular pattern spicules (Hong et al., 2012) may belong to the family Anthaspidellidae. The occurrence of metazoan-microbial reefs in the


Figure 6. Box plots of measured values of some studied specimens (n = 53). For raw data, see Supplementary Table 1.


C. orientalis were framework builders, in which R. zhangxianensis and C. orientalis were encrusted and stabilized by micro- stromatolites. The Epiphyton-Rankenella-Cambroctoconus reefs most likely grew within a shallow subtidal environment, where ooid shoals formed (Woo, 2009). Some reef-building organisms would have been reworked and deposited within reef-flank sediments (Fig. 3.2). The other examples of Cambrian reef-building anthaspidellid


sponges include R. mors (late Drumian, Australia) (Kruse and Reitner, 2014), R. hamdii (early Paibian, Iran) (Hamdi et al., 1995; Kruse and Zhuravlev, 2008), Gallatinospongia conica Okulitch and Bell, 1955 (early Paibian, Nevada and California, USA) (Shapiro and Rigby, 2004), Wilbernicyathus donegani Wilson, 1950 (Jiangshanian–Stage 10, Texas and Colorado, USA) (Johns et al., 2007), and an unidentified anthaspidellid sponge (Jiangshanian–Stage 10, Nevada, USA) (Mrozek et al., 2003; Dattilo et al., 2004) (Fig. 1). Among these examples, reefs containing R. mors may be comparable to those of this study in terms of their age. Although the age of the Australian reef is only poorly constrained (late Drumian; Kruse and Reitner, 2014), the relatively large difference in time suggests that R. zhangxianensis (late Stage 5–early Guzhangian) is the oldest reef-building anthaspidellid sponge ever reported. There are also somereports of reef-building non-anthaspidellid


sponges during the Cambrian Series 3–Furongian. The heteractinide sponge Jawonya gurumal Kruse, 1987, and Wagima galbanyin Kruse, 1987 (late Cambrian Stage 4–early Cambrian Stage5)occurwithin Kordephyton-dominant reefs as dwellers (Kruse, 1996; Kruse and Reitner, 2014). Orlinocyathus Krasnopeeva in Vologdin, 1962, which is classified in family Streptosolenidae (Finks et al., 2004) and thought to be a junior synonym of Gallatinospongia (Finks et al., 2004) or Rankenella (Kruse and Zhuravlev, 2008), formed reefs with Epiphyton in the


Cambrian Series 3 together with other occurrences in the Furongian indicates that the metazoan reef gap after the decline of archaeocyaths could have been shorter than previously suggested (e.g., Hong et al., 2012; Kruse and Reitner, 2014; Lee et al., 2014a). Further studies on the Cambrian Series 3–Furongian reefs may improve our understanding of the geological events during these periods.


Acknowledgments


Comments by P.D. Kruse and R.S. Shapiro greatly improved the quality of the present paper. We thank R.J. Elias for carefully correcting the English, M. Carrera and A. Pisera for proofreading the earlier version of the manuscript, and H.-J. Park for preparing thin sections. This study was supported by the KOPRI fund (PM15030 funded by the MOF, Korea) to J.W. and by the Korea Research Foundation grants funded by the Korean Government (MOEHRD) (KRF-NRF-2013R1A2A2A01067612) to D.-J.L.


Accessibility of supplemental data


Supplemental data deposited in Dryad data package: http://dx.doi.org/10.5061/dryad.f4168


References Adachi, N., Ezaki, Y., and Liu, J., 2011, Early Ordovician shift in reef construction from microbial to metazoan reefs: Palaios, v. 26, p. 106–114.


Adachi, N., Ezaki, Y., Liu, J., and Cao, J., 2009, Early Ordovician reef construction in Anhui Province, South China: a geobiological transition from microbial- to metazoan-dominant reefs: Sedimentary Geology, v. 220, p. 1–11.


Beresi,M.S., and Rigby, J.K., 1994, Sponges and chancelloriids fromthe Cambrian of western Argentina: Journal of Paleontology, v. 68, p. 208–217.


Bornemann, J.G., 1886, Die Versteinerungen des cambrischen Schichtensystems der Insel Sardinien nebst vergleichenden Untersuchungen über analoge Vorkomm- nisse aus anderen Ländern: Verhandlungen der Kaiserlichen Leopoldinisch- Carolinischen-Deutschen Akademie der Naturforscher, v. 51, p. 1–148.


Cañas, F., and Carrera,M., 1993, Early Ordovician microbial-sponge-receptaculitid bioherms of the Precordillera, western Argentina: Facies, v. 29, p. 169–178.


Carrera, M.G., and Rigby, J.K., 2004, Sponges, in Webby, B.D., Paris, F., Droser, M.L., and Percival, I.G., eds., The Great Ordovician Biodiversification Event: New York, Columbia University Press, p. 102–111.


Choh, S.-J., Hong, J., Sun, N., Kwon, S.-W., Park, T.-Y., Woo, J., Kwon, Y.K., Lee, D.-C., and Lee, D.-J., 2013, Early Ordovician reefs from the Taebaek Group, Korea: constituents, types, and geological implications: Geosciences Journal, v. 17, p. 139–149.


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