Polymerid Trilobites from the Cambrian of Northwestern Hunan, China

Home , Asaphida, Corynexochida, Lichida, Olenina, Paibi, Ptychagnostus

POLYMERID TRILOBITES FROM THE CAMBRIAN OF NORTHWESTERN HUNAN, CHINA

Volume 1 Corynexochida, Lichida, and Asaphida

PENG Shanchi Loren E. BABCOCK LIN Huanling

Science Press Beijing

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Responsible Editresses: HU Xiaochun and LIN Caihua

POLYMERID TRILOBITES FROM THE CAMBRIAN OF NORTHWESTERN HUNAN, CHINA Volume 1 Corynexochida, Lichida, and Asaphida PENG Shanchi, Loren E. BABCOCK, and LIN Huanling

Published by Science Press http://www. sciencep. com 16 Donghuangchenggen North Street Beijing 100717 P. R. China

Printed in Beijing, 2004 Reprinted in Beijing, 2006

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the copyright owner.

ISBN 7-03-014905-X/Q· 1538

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LIST OF AUTHORS

PENG Shanchi Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences 39 East Beijing Road Nanjing 210008, China

Loren E. BABCOCK Department of Geological Sciences The Ohio State University 275 Mendenhall Laboratory 125 South Oval Mall Columbus, Ohio 43210, USA

LIN Huanling Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences 39 East Beijing Road Nanjing 210008, China

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This research was funded by

National Natural Science Foundation of China (49070077, 40072003, 40023002, 40332018)

Chinese Academy of Sciences (KZCX2-SW-129)

Ministry of Technology and Science of China (2001 DEB20056, G2000077700)

National Geographic Society (No. 5819-96; 7151-01)

State Key Laboratory of Paleobiology and Stratigraphy (No. 933114)

State Education Commission of China The Ohio State University

US National Science Foundation (EAR 9405990, 9526709, 0073089, 0106883, EAR OPP-0346829)

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FOREWORD

China is richly endowed with Cambrian strata yielding some of the best-preserved fossils known anywhere in the world. The trilobites are most important element in the fauna, and of scientific relevance for several reasons. First, they are of regional importance in the precise correlation of strata, and are of primary use in characterising mappable formations. Second, some of the species are widespread internationally, and these permit the placing of Chinese stratigraphical schemes within the global chronostratigraphy. Thirdly, the variety, relationships and endemicity of the faunas contributes to the broad questions of how evolution proceeded in the Cambrian, and is relevant to debates about whether special conditions applied at the early stage of the Phanerozoic radiation. The polymerid trilobite faunas of northwestern Hunan are remarkable for their diversity and excellence of preservation. Many of them belong to genera confined to China or to its palaeogeographic neighbours. However, some of these important taxa have remained imperfectly known or undescribed. This monograph makes good this omission. Thus in several cases pygidia or free cheeks are assigned where they had not been known previously, thus providing a much fuller picture of morphology in assessing relationships. This is particularly welcome where the species concerned is the type of its genus. In addition a number of new genera are added to the fauna. The paper also documents the endemic radiation of the specialised and interesting Dameselloidea, a family showing some of the most specialised pygidia in the Trilobita. The systematics of these trilobites is fully discussed, and the whole work is illustrated by photographs of the highest quality. This work should remain the standard account for the foreseeable future. The detailed work on the trilobites is placed in the wider context of biostratigraphy and correlation, which should be of interest to all those concerned with Cambrian geology. A refinement of the biostratigraphic zones based on the ranges of trilobite species will have implications for those currently seeking to increase the precision in international correlation of subdivisions within the Cambrian. Careful new work, of which this paper is an excellent example, is a more valuable contribution than almost anything else in this endeavour.

Professor Richard A. Fortey F R S Department of Palaeontology The Natural History Museum and Department of Zoology Oxford University

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CONTENTS

FOREWORD...... i INTRODUCTION...... 1 ACKNOWLEDGMENTS...... 2 REPOSITORIES ...... 2 PREVIOUS WORK...... 3 GEOLOGIC SETTING...... 4 PALEOGEOGRAPHY ...... 4 STRATIGRAPHY ...... 4 MEASURED SECTIONS...... 10 CORRELATION...... 40 NORTH CHINA AND NORTHEAST CHINA PLATFORMS ...... 40 TARIM AND NORTHWEST CHINA ...... 40 WESTERN ZHEJIANG...... 42 AUSTRALIA ...... 42 BALTICA...... 42 KAZAKHSTAN...... 43 LAURENTIA ...... 43 SIBERIA ...... 43 SYSTEMATIC PALEONTOLOGY ...... 44 Class TRILOBITA Walch, 1771...... 44 Order CORYNEXOCHIDA Kobayashi, 1935 ...... 44 Suborder CORYNEXOCHINA Kobayashi, 1935 ...... 44 Family CORYNEXOCHIDAE Angelin, 1854...... 44 Genus CORYNEXOCHUS Angelin, 1854 ...... 44 Corynexochus xiangxiensis sp. nov...... 45 Genus CORYNEXOCHINA Lermontova, 1940 ...... 46 Corynexochina sinensis sp. nov...... 47 Genus CHATIANIA Yang in Zhou et al., 1977...... 48 Chatiania chatianensis Yang in Zhou et al., 1977...... 49 Chatiania expansa (Yuan and Yin, 1998)...... 52 Chatiania sp. cf. C. chatianensis Yang in Zhou et al., 1977...... 53 Chatiania convexa sp. nov...... 53 Family DOLICHOMETOPIDAE Walcott, 1916...... 54 Genus AMPHOTON Lorenz, 1906 ...... 54 Amphoton deois (Walcott, 1905)...... 56 Amphoton alceste (Walcott, 1905) ...... 57 Amphoton sp. cf. A. typicum (Kobayashi, 1942a) ...... 59 Genus FUCHOUIA Resser and Endo in Kobayashi, 1935 ...... 60 Fuchouia chiai Lu, 1957 ...... 62 Fuchouia kuruktagensis Zhang, 1981 ...... 64 · iii·

Fuchouia oratolimba Yang in Zhou et al., 1977...... 65 Fuchouia bulba sp. nov...... 67 Fuchouia sixinensis sp. nov...... 68 Fuchouia sp. indet...... 69 Family DORYPYGIDAE Kobayshi, 1935...... 70 Genus DORYPYGE Dames, 1883 ...... 70 Dorypyge richthofeni Dames, 1883...... 71 Dorypyge perconvexalis Yang in Zhou et al., 1977...... 73 Dorypyge bisulcata sp. nov...... 75 Dorypyge huaqiaoensis sp. nov...... 76 Dorypyge globosa sp. nov...... 77 Dorypyge? sp...... 78 Suborder LEIOSTEGIINA Bradley, 1925 ...... 79 Superfamily LEIOSTEGIOIDEA Bradley, 1925 ...... 79 Family LEIOSTEGIIDAE Bradley, 1925...... 79 Subfamily LEIOSTEGIINAE Bradley, 1925...... 79 Genus CHUANGIA Walcott, 1911...... 79 Chuangia subquadrangulata Sun, 1935...... 79 Chuangia austriaca Yang in Zhou et al., 1977 ...... 80 Genus MEROPALLA Öpik, 1967...... 81 Meropalla bella Yuan and Yin, 1998...... 82 Meropalla gibbera sp. nov...... 82 Subfamily CHELIDONOCEPHALINAE Wittke, 1984 ...... 83 Genus GEMINICLAVULA gen. nov...... 83 Geminiclavula wangcunica gen. et sp. nov...... 84 Subfamily CHIAWANGELLINAE Chu, 1959 ...... 84 Genus CHIAWANGELLA Chu, 1959...... 85 Chiawangella hunanensis sp. nov...... 86 Subfamily ORDOSIINAE Lu, 1954 ...... 89 Genus WANSHANIA Rong and Yang in Zhou et al., 1977 ...... 89 Wanshania wanshanensis Rong and Yang in Zhou et al., 1977 ...... 90 Subfamily PAGODIINAE Kobayashi, 1935...... 93 PAGODIINAE gen. et sp. indet...... 93 Genus PROCHUANGIA Kobayashi, 1935 ...... 93 Prochuangia granulosa Lu, 1956...... 94 Prochuangia linicispinata Peng, 1992 ...... 95 Prochuangia sp. cf. P. leiocephala Peng, Geyer, and Hamdi, 1999 ...... 95 Order LICHIDA Moore, 1959...... 96 Superfamily DAMESELLOIDEA Kobayashi, 1935...... 96 Family DAMESELLIDAE Kobayashi, 1935...... 96 Subfamily DAMESELLINAE Kobayashi, 1935 ...... 96 Genus DAMESELLA Walcott, 1905...... 96 Damesella hunanensis sp. nov...... 96 Damesella? sp...... 98 Genus BLACKWELDERIA Walcott, 1906 ...... 98 Blackwelderia youshuica sp. nov...... 99 Blackwelderia? sp...... 100 Genus PARABLACKWELDERIA Kobayashi, 1942b ...... 101 Parablackwelderia jimaensis (Yang in Lu et al., 1974a)...... 104

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Parablackwelderia laterilobata (Yang in Zhou et al., 1977)...... 108 Parablackwelderia sp. cf. P. huabeiensis (Zhang in Qiu et al., 1983)...... 109 Parablackwelderia yangi sp. nov...... 110 Parablackwelderia sp...... 111 Genus PROTAITZEHOIA Yang 1978 in Yin and Li, 1978 ...... 112 Protaitzehoia yuepingensis Yang in Yin and Li, 1978...... 114 Protaitzehoia granifera Yang in Yin and Li, 1978 ...... 115 Protaitzehoia subquadrata Peng, 1987 ...... 117 Protaitzehoia spinifera sp. nov...... 119 Protaitzehoia sp...... 120 Subfamily DORYPYGELLINAE Kobayashi, 1935 ...... 121 Genus TEINISTION Monke, 1903...... 121 Teinistion posterocostum (Yang in Zhou et al., 1977)...... 123 Genus TAIHANGSHANIA Zhang and Wang, 1985 ...... 125 Taihangshania wangcunensis sp. nov...... 126 Subfamily DREPANURINAE Hupé, 1953...... 128 Genus DREPANURA Bergeron, 1899 ...... 128 Drepanura ? crassispina sp. nov...... 129 Genus PALAEADOTES Öpik, 1967...... 130 Palaeadotes hunanensis (Yang in Zhou et al., 1977)...... 132 Palaeadotes bella (Qiu in Qiu et al., 1983)...... 136 Genus PARADAMESELLA Yang in Zhou et al., 1977...... 137 Paradamesella typica Yang in Zhou et al., 1977...... 139 Paradamesella peculiaris Zhou in Zhou et al., 1977...... 142 Paradamesella nobilis Lu and Lin, 1989 ...... 145 Superfamily ODONTOPLEUROIDEA Kobayashi, 1935 ...... 145 Family EOACIDASPIDAE Poletaeva, 1957 ...... 145 Genus PARAACIDASPIS Poletaeva, 1960...... 146 Paraacidaspis hunanica Egorova in Poletaeva, 1960 ...... 147 Paraacidaspis sp...... 149 Order ASAPHINA Salter, 1864...... 150 Superfamily ANOMOCARAROIDEA Poulsen, 1927 ...... 150 Family ANOMOCARIDAE Poulsen, 1927 ...... 150 Genus AFGHANOCARE Wolfart, 1974...... 150 Afghanocare truncatum (Peng, 1987) ...... 150 Genus GLYPHASPELLUS Ivshin, 1953...... 152 Glyphaspellus? sinensis sp. nov...... 152 Genus PARACOOSIA Kobayashi, 1936...... 153 Paracoosia sp. cf. P. kingi Wittke, 1984...... 154 Paracoosia huayuanensis sp. nov...... 156 Genus PAIBIANOMOCARE gen. nov...... 157 Paibianomocare paibiense gen. et sp. nov...... 158 Paibianomocare lineatum gen. et sp. nov...... 159 Family PTEROCEPHALIIDAE Kobayashi, 1935 ...... 160 Subfamily CILIINAE Peng, 1992 ...... 160 Genus YANGWEIZHOUIA Yuan and Yin, 1998...... 161 Yangweizhouia carinata Yuan and Yin, 1998...... 161 Superfamily ASAPHOIDEA Salter, 1864 ...... 162 Family CERATOPYGIDAE Linnarsson, 1869...... 162

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Subfamily CERATOPYGINAE Linnarsson, 1869...... 162 Genus PROCERATOPYGE Wallerius, 1895...... 162 Subgenus PROCERATOPYGE (PROCERATOPYGE) Wallerius, 1895 ...... 163 Proceratopyge (Proceratopyge) fenghwangensis Hsiang in Egorova et al., 1963...... 163 Proceratopyge (Proceratopyge) fuyangensis Lu and Lin in Peng, 1987 ...... 164 Proceratopyge (Proceratopyge) truncata Yang in Zhou et al., 1977 ...... 165 Proceratopyge sp. indet...... 166 Subfamily IWAYASPIDINAE Kobayashi, 1962 ...... 166 Genus PSEUDOYUEPINGIA Chien, 1961 ...... 166 Pseudoyuepingia laochatianensis Yang in Zhou et al., 1977 ...... 167 Superfamily TRINUCLEOIDEA Hawle and Corda, 1847 ...... 169 Family ALSATASPIDIDAE Turner, 1940...... 169 Subfamily HAPALOPLEURINAE Harrington and Leanza, 1957(nom. trans. ex. Hapalopleuridae Harrington and Leanza, 1957)...... 169 Genus GAOLOUPINGIA Yuan and Yin, 1998...... 170 Gaoloupingia gaoloupingensis Yuan and Yin, 1998 ...... 170 Genus AJRIKINA Kraskov in Borovikov and Kraskov, 1963...... 171 Ajrikina wannanensis (Qiu in Qiu et al., 1983)...... 172 Ajrikina hunanensis (Peng, 1987) ...... 173 Genus TORIFERA Wolfart, 1974...... 174 Torifera taoyuanensis (Peng, 1987) ...... 175 Torifera tuma (Yang in Zhou et al., 1977)...... 176 Torifera abrupta sp. nov...... 178 Torifera? paraconvexa (Yang in Yin and Li, 1978)...... 179 Family LIOSTRACINIDAE Raymond, 1937 ...... 180 Genus LIOSTRACINA Monke, 1903...... 180 Liostracina bella Lin and Zhou, 1983...... 180 Superfamily UNCERTAIN ...... 181 Family MONKASPIDIDAE Kobayashi, 1935...... 181 Genus MONKASPIS Kobayashi, 1935...... 181 Monkaspis quadrata Yang in Zhou et al., 1977...... 183 Genus METOPOTROPIS Öpik, 1967 ...... 184 Metopotropis sinensis sp. nov...... 184 REFERENCES...... 186 INDEX OF SPECIES AND GENERA ...... 201 PLATES ...... 207

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CONTENTS

INTRODUCTION...... 1 ACKNOWLEDGMENTS...... 1 REPOSITORIES ...... 1 SYSTEMATIC PALEONTOLOGY ...... 7 Order PTYCHOPARIIDA Swinnerton, 1915 ...... 7 Suborder PTYCHOPARIINA Richter, 1933...... 7 Superfamily PTYCHOPARIOIDAE Matthew, 1887...... 7 ?Family PTYCHOPARIIDAE Matthew, 1887...... 7 Genus TOWNLEYELLA Öpik, 1967...... 7 Townleyella rara Yuan and Yin, 1998...... 7 Genus XILINGXIA Lu in Zhang et al., 1980 ...... 8 Xilingxia ichangensis (Chang, 1964) ...... 9 Ptychopariid gen. et sp. indet...... 10 Superfamily ASAPHISCOIDEA Raymond, 1924 ...... 11 Family ANOMOCARELLIDAE Hupé, 1953...... 11 Genus FISSANOMOCARELLA Peng, Lin, and Chen, 1995...... 11 Fissanomocarella paibiensis Peng, Lin, and Chen, 1995 ...... 11 Genus HUAYUANIA Peng, Lin, and Chen, 1995 ...... 11 Huayuania subcalva Peng, Lin, and Chen, 1995 ...... 12 Huayuania quadrilateralis (Resser and Endo, 1937)...... 12 Genus PARANOMOCARELLA Yang in Zhou et al., 1977 ...... 14 Paranomocarella parallela Yang in Zhou et al., 1977 ...... 15 Paranomocarella fortis Peng, Lin, and Chen, 1995...... 17 Paranomocarella similaris sp. nov...... 18 Paranomocarella sp...... 19 Paranomocarella? obvia sp. nov...... 19 Genus SZEASPIS Chang, 1959...... 20 Szeaspis huananensis sp. nov...... 21 Family PROASAPHISCIDAE Chang, 1963...... 22 Genus PROASAPHISCUS Resser and Endo in Kobayashi, 1935...... 22 Proasaphiscus? sp. cf. P. butes (Walcott, 1905)...... 23 Subgenus PROASAPHISCUS (HONANASPIS) Chang, 1959...... 23 Proasaphiscus (Honanaspis)? sp. cf. P. (H.) parvus Kuo in Lu et al., 1965 ...... 24 Genus ADELOGONUS Öpik, 1967...... 25 Adelogonus hunanensis sp. nov...... 26 Adelogonus? sp...... 27 Genus EYMEKOPS Resser and Endo, 1937...... 28 Eymekops? sp. 1 ...... 28 Eymekops? sp. 2 ...... 29 Genus GRANDIOCULUS Cossmann, 1908...... 29 · i·

Grandioculus obscurus sp. nov...... 31 Grandioculus truncatus sp. nov...... 32 Genus HUAYUANASPIS gen. nov...... 33 Huayuanaspis granulosa gen. et sp. nov...... 34 Huayuanaspis perpauca gen. et sp. nov...... 35 Huayuanaspis? sp...... 36 Genus INIOTOMA Öpik, 1967 ...... 37 Iniotoma laevis sp. nov...... 37 Iniotoma porosus sp. nov...... 38 Genus MAOTUNIA Zhang and Jell, 1987...... 39 Maotunia sp. cf. M. blackwelderi (Resser and Endo, 1937)...... 39 Maotunia sp. cf. M. semiplectra Zhang and Jell, 1987...... 41 Maotunia rectangularis sp. nov...... 41 Maotunia sp...... 43 Genus SUDANOMOCARINA Jell in Jell and Robison, 1978...... 43 Sudanomocarina traynorae Zhang and Jell, 1987...... 44 Sudanomocarina sp. cf. S. changi Jell in Jell and Robison, 1978 ...... 44 Sudanomocarina? huananensis sp. nov...... 45 Sudanomocarina sp...... 47 Genus ZHUJIA Ju in Qiu et al., 1983...... 47 Zhujia hunanensis Peng, Lin, and Chen, 1995...... 48 Genus PAIBIELLA gen. nov...... 48 Paibiella paibiensis gen. et sp. nov...... 49 Genus PARAYUJINIA gen. nov...... 50 Parayujinia constricta gen. et sp. nov...... 50 Family CATILLICEPHALIDAE Raymond, 1938 ...... 52 Subfamily CATILLICEPHALINAE Raymond, 1938...... 52 Genus BUTTSIA Wilson, 1951...... 52 Buttsia globosa Lu and Lin in Peng, 1987 ...... 53 Genus MADAROCEPHALUS Resser, 1938a ...... 55 Madarocephalus orientalis sp. nov...... 56 Genus PARADISTAZERIS Zhu in Zhang et al., 1980a ...... 57 Paradistazeris hubeiensis Zhu in Zhang et al., 1980a ...... 58 Paradistazeris hunanensis (Peng, 1987) ...... 58 Paradistazeris rotundus sp. nov...... 59 Paradistazeris sp...... 60 Subfamily ONCHONOTININAE Lu, 1965...... 61 Genus HUZHUIA Chu, 1965 ...... 62 Huzhuia paratypica Yang, 1978...... 63 Huzhuia curvata sp. nov...... 64 Huzhuia latilimbata sp. nov...... 65 Genus ONCHONOTELLUS Lermontova in Ivshin, 1956 ...... 66 Onchonotellus curvitensus sp. nov...... 67 Genus PLACOSEMA Öpik, 1967 ...... 68 Placosema bigranulosum sp. nov...... 68 Family CREPICEPHALIDAE Kobayashi, 1935 ...... 69 Genus CREPICEPHALINA Resser and Endo in Kobayashi, 1935 ...... 69 Crepicephalina pergranosa Resser and Endo, 1937...... 69 Crepicephalina sp. cf. C. quadrata Resser and Endo, 1937...... 70

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Crepicephalina? sp...... 71 Genus METEORASPIS Resser, 1935...... 71 Meteoraspis sp. cf. M. orientalis Yuan and Yin, 1998...... 72 Family DICERATOCEPHALIDAE Lu, 1954...... 73 Genus FENGHUANGELLA Yang in Zhou et al., 1977 ...... 73 Fenghuangella laochatianensis laochatianensis Yang in Zhou et al., 1977...... 74 Fenghuangella laochatianensis crassa subsp. nov...... 76 Fenghuangella coniforma Yang in Zhou et al., 1977 ...... 77 Fenghuangella liostracinala Yang in Zhou et al., 1977 ...... 79 Fenghuangella fusilis sp. nov...... 80 Family DOKIMOCEPHALIDAE Kobayashi, 1935 ...... 81 Subfamily CONOKEPHALININAE Hupé, 1955...... 81 Genus LOBOCEPHALINA Rùžièka, 1940...... 81 Lobocephalina sinensis sp. nov...... 82 Family EULOMIDAE Kobayashi, 1955 ...... 83 Subfamily EULOMINAE Kobayashi, 1955 ...... 83 Genus STIGMATOA Öpik, 1963...... 83 Stigmatoa yangziensis Yang in Zhou et al., 1977 ...... 84 Family KINGSTONIIDAE Kobayashi, 1933b ...... 85 Genus KINGSTONIA Walcott, 1924 ...... 85 Kingstonia euryaxis sp. nov...... 85 Family LISANIIDAE Chang, 1963...... 87 Genus LISANIA Walcott, 1911 ...... 87 Lisania paratungjenensis Yang in Zhou et al., 1977 ...... 90 Lisania yuanjiangensis (Yang in Zhou et al., 1977) ...... 92 Lisania sp. cf. L. agonius (Walcott, 1905) ...... 94 Lisania paibiensis sp. nov...... 95 Lisania wangcunensis sp. nov...... 97 Lisania? sp...... 97 Genus BAOJINGIA Yang in Zhou et al., 1977 ...... 98 Baojingia youshuiensis Yang in Zhou et al., 1977...... 99 Baojingia jiudiantangensis (Yang in Zhou et al., 1977) ...... 101 Baojingia latilimbata (Peng, 1987) ...... 102 Baojingia paralala (Yang in Zhou et al., 1977)...... 103 Baojingia quadrata (Yang in Zhou et al., 1977)...... 104 Baojingia subquadrata (Yang, 1978)...... 106 Baojingia tungjenensis (Nan in Egorova et al., 1963)...... 108 Genus NEOANOMOCARELLA Hsiang in Egorova et al., 1963 ...... 109 Neoanomocarella asiatica Hsiang in Egorova et al., 1963...... 110 Neoanomocarella incilis sp. nov...... 112 Genus QIANDONGASPIS Yuan and Yin, 1998 ...... 113 Qiandongaspis sinensis (Peng, 1987)...... 114 Qiandongaspis convexa sp. nov...... 115 Qiandongaspis xiangxiensis sp. nov...... 116 Qiandongaspis sp...... 117 Genus SHENGIA Hsiang in Egorova et al., 1963...... 117 Shengia quadrata Hsiang in Egorova et al., 1963...... 118 Shengia trapezia Peng, 1992 ...... 119 Shengia wannanensis Qiu in Qiu et al., 1983...... 120

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Shengia sp...... 121 Family LONCHOCEPHALIDAE Hupé, 1953 ...... 121 Genus AETHIA Qian and Zhou, 1984...... 121 Aethia rectangula Qian and Zhou, 1984 ...... 122 Genus NEOGLAPHYRASPIS Yuan and Yin, 1998...... 122 Neoglaphyraspis nitida Yuan and Yin, 1998 ...... 123 Genus PRODAMESELLA Chang, 1959 ...... 124 Prodamesella punctata Ergaliev, 1980 ...... 125 Prodamesella sp. cf. P. biserrata Jell in Jell and Robison, 1978...... 126 Prodamesella tumidula sp. nov...... 127 Family MAPANIIDAE Chang, 1963...... 128 Genus MAPANIA Resser and Endo in Kobayashi, 1935...... 128 Mapania jiangnanensis sp. nov...... 129 Family ONCHONOTOPSIDAE Shaw, 1966...... 130 Genus LUYANHAOASPIS Peng, Babcock, and Lin, 2001b...... 130 Luyanhaoaspis decorosa (Peng, Lin, and Chen, 1995)...... 131 Luyanhaoaspis inflata sp. nov...... 132 Luyanhaoaspis sp. cf. L. inflata sp. nov...... 132 Genus HUAYUANELLA gen. nov...... 133 Huayuanella paibiensis gen. et sp. nov...... 134 Huayuanella zhiqiangi gen. et sp. nov...... 134 Family PAPYRIASPIDIDAE Whitehouse, 1939 ...... 135 Genus PIANASPIS Saito and Sakakura, 1936...... 135 Pianaspis attenuata (Lermontova and Chernysheva in Chernysheva, 1950)...... 137 Pianaspis sinensis (Yang in Zhou et al., 1977)...... 139 Genus WANGCUNIA Peng, Lin, and Chen, 1995...... 140 Wangcunia wangcunensis Peng, Lin, and Chen, 1995...... 140 Genus PARAPIANASPIS gen. nov...... 141 Parapianaspis hunanensis gen. et sp. nov...... 142 Family RHYSSOMETOPIDAE Öpik, 1967 ...... 143 Genus RHYSSOMETOPUS Öpik, 1967...... 143 Rhyssometopus zhongguoensis Zhou in Zhou et al., 1977 ...... 143 Family SOLENOPLEURIDAE Angelin, 1854 ...... 144 Genus CHANGQINGIA Lu and Zhu in Qiu et al., 1983 ...... 144 Changqingia intermedia (Walcott, 1906)...... 144 Changqingia laevis Peng, Lin, and Chen, 1995 ...... 145 Genus MENOCEPHALITES Kobayashi, 1935...... 145 Menocephalites sp. cf. M. pauperata (Walcott, 1906) ...... 146 Menocephalites hunanensis sp. nov...... 147 Menocephalites? sp. 1 ...... 148 Menocephalites? sp. 2 ...... 148 Family SHUMARDIIDAE Lake, 1907...... 149 Genus OCULISHUMARDIA Peng, Babcock, Hughes, and Lin, 2003...... 149 Oculishumardia hunania Peng, Babcock, Hughes, and Lin, 2003...... 149 Genus LIMBISHUMARDIA gen. nov...... 150 Limbishumardia wangcunensis gen. et sp. nov...... 151 PTYCHOPARIOIDAE FAMILY UNCERTAIN...... 152 Genus PSEUDOMAPANIA Yuan and Yin, 1998...... 152 Pseudomapania cylindrica Yuan and Yin, 1998...... 152

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Suborder OLENINA Burmeister, 1843 ...... 153 Superfamily OLENOIDEA Burmeister, 1843...... 153 Family OLENIDAE Burmeister, 1843...... 153 Subfamily OLENINAE Burmeister, 1843 ...... 153 Genus OLENUS Dalman, 1827 ...... 153 Olenus austriacus Yang in Zhou et al., 1977...... 153 Olenus punctatus sp. nov...... 155 Subfamily PELTURINAE Corda, 1847...... 156 Genus SULCARECLAVA gen. nov...... 156 Sulcareclava sagitta gen. et sp. nov...... 157 Suborder HARPINA Whittington, 1959...... 158 ?Family HARPIDIDAE Whittington, 1950...... 158 Genus BAIKADAMASPIS Ergaliev, 1980...... 158 Baikadamaspis sinensis (Yang in Zhou et al., 1977) ...... 159 Baikadamaspis sp. cf. B. granulosa (Yuan and Yin, 1998) ...... 161 Baikadamaspis linearis sp. nov...... 161 Baikadamaspis paibiensis sp. nov...... 163 Baikadamaspis sp...... 165 TRILOBITA ORDER UNCERTAIN ...... 165 Family BURLINGIIDAE Walcott, 1908...... 165 Genus SCHMALENSEEIA Moberg, 1903 ...... 165 Schmalenseeia sinensis Yang in Yin and Li, 1978...... 167 Schmalenseeia fusilis sp. nov...... 170 UNDETERMINED TRILOBITE SCLERITES...... 171 Family UNDETERMINED...... 171 Genus Undetermined...... 171 Undetermined larva ...... 171 Undetermined pygidium 1...... 172 Undetermined pygidium 2...... 172 Undetermined librigena 1...... 173 Undetermined librigena 2...... 173 Undetermined librigena 3...... 173 Undetermined librigena 4...... 174 Undetermined hypostome 1...... 174 Undetermined hypostome 2...... 175 Order EODISCIDA Kobayashi, 1939 ...... 175 Suborder EODISCINA Kobayashi, 1939...... 175 Superfamily EODISCOIDEA Raymond, 1913...... 175 Family EODISCIDAE Raymond, 1913...... 175 Genus HELEPAGETIA Jell, 1975 ...... 175 Helepagetia bitruncula Jell, 1975 ...... 176 REFERENCES...... 177 INDEX OF SPECIES AND GENERA ...... 191 PLATES ...... 199

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LIST OF TEXT-FIGURES

Text-figure 1. Map showing distribution of rocks assigned to the Jiangnan Slope Belt facies (Cambrian) in Hunan and Guizhou provinces, China Text-figure 2. Table showing the correlation of polymerid and agnostoid biozones recognized within the Huaqiao Formation of northwestern Hunan, China Text-figure 3. Geological map of northwestern Hunan, China, showing locations of measured stratigraphic sections near Paibi and Wangcun Text-figure 4. Zonation and observed stratigraphic distribution of non-agnostoid species in the Huaqiao Formation of the Paibi section near Paibi, Huayuan, northwestern Hunan Text-figure 5. Zonation and observed stratigraphic distribution of non-agnostoid species in the Huaqiao Formation of the Paibi-2 section near Paibi, Huayuan, northwestern Hunan Text-figure 6. Zonation and observed stratigraphic distribution of non-agnostoid species in the Huaqiao Formation of the Wangcun section, northwestern Hunan Text-figure 7. Correlation of zonal sequence for the studied interval of Huaqiao Formation in northwestern Hunan in South China with zonal schemes for the North and Northeast China Platform, Western Zhejiang in East China, and Tarim in North- west China, and the zonal schemes of other continents Text-figure 8. Chatiania chatianensis Yang in Zhou et al., 1977. Reconstruction of cephalon and pygidium, and lectotype Text-figure 9. Reconstruction of cranidium and pygidium of Chiawangella hunanensis sp. nov. Text-figure 10. Type material of Wanshania wanshanensis Rong and Yang in Zhou et al., 1977 and specimens referred to the species Text-figure 11. Reconstructions of some species attributed to Parablackwelderia Kobayashi, 1942 Text-figure 12. Type material of Paradamesops jimaensis Yang in Lu et al., 1974a Text-figure 13. Parablackwelderia sp. Text-figure 14. Holotype cranidium of Protaitzehoia yuepingensis Yang in Yin and Li, 1978 Text-figure 15. Holotype cranidium of Protaitzehoia granifera Yang in Yin and Li, 1978 Text-figure 16. Holotype cranidium of Protaitzehoia subquadrata Peng, 1987 Text-figure 17. Type material of Teinistion posterocostum (Yang in Zhou et al., 1977) Text-figure 18. Reconstruction of cranidium and pygidium of Taihangshania wangcunensis sp. nov. Text-figure 19. Type material of Bergeronites hunanensis Yang in Zhou et al., 1977, transferred to Palaeadotes Öpik, 1967 Text-figure 20. Reconstruction of dorsal exoskeleton of Palaeadotes hunanensis (Yang in Zhou et al., 1977) Text-figure 21. Type material of Paradamesella typica Yang in Zhou et al., 1977

Text-figure 22. Reconstruction of dorsal exoskeleton of Paradamesella typica Yang in Zhou et al., 1977 Text-figure 23. Holotype of Paradamesella peculiaris Zhou in Zhou et al., 1977 and specimens referred to the species Text-figure 24. Reconstruction of cephalon and pygidium of Paraacidaspis hunanica Jegorova in · vii·

Poletaeva, 1960 Text-figure 25. Lectotype of Coosia asiatica Mansuy, the type species of Paracoosia Kobayashi, 1938 Text-figure 26. Reconstruction of cephalon and pygidium of Paracoosia sp. cf. P. kingi Witteke, 1984 Text-figure 27. Holotype cranidium and associated paratype pygidium of Proceratopyge (Pro- ceratopyge) truncata Yang in Zhou et al., 1977 Text-figure 28. Lectotype of Pseudoyuepingia laochatianensis Yang in Zhou et al., 1977 Text-figure 29. Reconstruction of cephalon of Torifera tuma (Yang in Zhou et al., 1977) Text-figure 30. Reconstruction of cephalon and pygidium of Liostracina bella Lin and Zhou, 1983 Text-figure 31. Lectotype of Monkaspis quadrata Yang in Zhou et al., 1977

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INTRODUCTION

The Wulingshan Mountains region of northwestern Hunan and eastern Guizhou provinces, China, contains some of the most complete and fossiliferous strata known in the upper part of the Cambrian. Easy access to good exposures has helped make this area the subject of numerous systematic, biostratigraphic, lithostratigraphic, chemostratigraphic, and sequence-stratigraphic studies. A west-to-east cross-section through eastern Guizhou and northwestern Hunan reveals a paleogeographic profile representing a shelf-to-basin transect through carbonate shelf paleo- environments of the Yangtze (or South China) Platform, the adjacent carbonate-dominated Jiangnan Slope Belt, and the more distal Jiangnan Basin (e.g., Gao and Duan, 1985; Lu and Qian, 1986; Liu et al., 1990; Pu and Ye, 1991; Peng and Babcock, 2001). In recent years, dark carbonates of the Huaqiao Formation, which represent the Jiangnan Slope Belt, have been particularly well studied as part of a larger effort to develop series and stage subdivisions within the Cambrian System. The Huaqiao Formation contains the most diverse trilobite fauna known from anywhere. More than 260 valid species occur through a stratigraphic interval of approximately 400 meters. Agnostoid trilobite species, 76 in number, were documented by Peng and Robison (2000), and many of them have intercontinental distributions and considerable utility for the correlation of strata globally. Agnostoid trilobites occurring in a section through the Huaqiao Formation of northwestern Hunan provide the key indicators for the base of the Paibian Stage and the Furongian Series, the first internationally ratified subdivisions within the Cambrian. The purpose of this two-volume set is to document the polymerid (or non-agnostoid) trilobites from the Huaqiao Formation of northwestern Hunan. A total of 196 species, some in open nomenclature, are reported, including a large number of new genera and new species. Some additional individual sclerites remain undetermined, however so the true diversity of polymerid taxa in the Huaqiao Formation is slightly greater than that reported here based on good, identifiable material. The polymerids have paleogeographic distributions ranging from regional to intercontinental. Most of the genera and some of the species are useful as biostratigraphic zonal indicators within Gondwana, and a few have utility intercontinentally. The work reported here continues and builds on earlier studies of the trilobite faunas and stratigraphy of northwestern Hunan by Peng (1984, 1987, 1990a, b, 1992), Peng and Robison (2000), Peng and Babcock (2001), and Peng et al. (1995, 2001a, 2001b, 2001c, 2001d, 2001e, 2001f, 2004). Volume 1 of this set contains general geologic information concerning the Huaqiao Formation of northwestern Hunan, lithostratigraphic data, biostratigraphic zonation, detailed descriptions of three stratigraphic sections, and the systematics of corynexochid, lichid, and asaphid trilobites. Volume 2 contains systematic treatments of ptychopariids, eodiscids, trilobites of uncertain affinity, and some undetermined sclerites. In both volumes, considerable effort was made to reillustrate type material of many previously described taxa. In some older literature, illustrations were not always reproduced well, so the new illustrations should help to clarify taxonomic concepts.

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ACKNOWLEDGMENTS

This work is the outgrowth of nearly two decades of field and laboratory work, and we are grateful to the numerous colleagues and institutions that have provided support for this effort over the years. Among them, Chen Yongan, G. Geyer, A. R. Palmer, R. A. Robison, J. H. Shergold, and Zhang Wentang (W. T. Chang), have been particularly helpful in a variety of aspects of the study. Han Yaojun, Luo Kunli, Li Jun, Li Yue, M. N. Rees, and Wang Huayu aided in collecting fossils. G. A. Wasserman helped to prepare and photograph specimens, and J. St. John helped to locate some references. Ren Yugao helped to draft figures, and K. Polak helped to prepare the manuscript for publication. Research was supported by grants to S. Peng from the National Natural Science Foundation of China (49070077, 40072003, 40023002, 40332018), the Chinese Academy of Sciences (KZCX2-SW-129), the Ministry of Technology and Science of China (2001 DEB20056, G2000077700), the State Key Laboratory of Paleobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (No. 933114), the National Geographical Society (No. 5819-96; 7151-01), the National Scholarship Council for International Studies, State Education Commission of China; and by grants to L. E. Babcock from the US National Science Foundation (EAR 9405990, 9526709, 0073089, 0106883, EAR OPP-0346829) and The Ohio State University (Seed Grant).

REPOSITORIES

All the specimens mentioned and described in the text, and illustrated on the text-figures and plates are reposited in the following institutions. Acronyms used to identify the repositories precede the repository names.

CUGB China University of Geology (Beijing), Beijing, China EM (E.N.S.M) École des Mines, Departement des Sciences de la Terre, Université de Lyon, France GMC Geological Museum of China, Beijing, China GPIBo Institut für Paläontologie, Universität Bonn, Germany HIT Nanjing Institute of Geology and Mineral Resources, the Chinese Academy of Geological Sciences, Nanjing, China MB Museum für Naturikund of Humboldt-Universität, Berlin, Germany NIGP Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, China USNM United States National Museum of Natural History, Smithsonian Institution, Washington, D.C., USA XTR Xinjiang Regional Surveying Team, Bureau of Geology and Mineral Resources, Ürümqi, China

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PREVIOUS WORK

Geologic study of the Cambrian stratigraphy in northwestern Hunan and eastern Guizhou began in the early Twentieth Century. Most of the major Cambrian lithologic units in eastern Guizhou were named during regional studies conducted by Ting (1930) and others during the 1940s (Tian, 1940; Lu, 1942, 1945; Liu, 1945; Yin et al., 1945; Wang, 1947). In western Hunan (Tian, 1940; Liu, 1945; Lu, 1956) and central Hunan (Wang and Pien, 1949; Liu, 1945), Cambrian lithologic units were investigated primarily in the search for mercury ore. During the 1960s and 1970s, regional geologic mapping and surveying conducted through Hunan and Guizhou resulted in the documentation of numerous Cambrian sections, and provided the basis for regional stratigraphic and paleogeographic syntheses. The work also provided important information about Cambrian faunas, and established the basis for comprehensive work on the biostratigraphy of the Hunan- Guizhou region (e.g., Qian, 1961; Egorova et al., 1963; Lin et al., 1966; Lu et al., 1974a; Yin and Li, 1978; Yang, 1978; Zhou et al., 1979, 1980; Peng and Tan, 1979; Peng, 1984, 1987, 1990a, 1990b, 1992; Dong 1990, 1991; Peng and Robison, 2000; Peng and Babcock, 2001; Peng et al., 2001a, 2001b, 2001c, 2001d, 2001e, 2001f, 2004; Dong and Bergström, 2001). Biostratigraphic zonation through Hunan and Guizhou forms a major part of the zonal scheme applied generally through the South China tectonic block (Peng, 2000; Peng and Babcock, 2001a; Peng et al., 2004).

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GEOLOGIC SETTING

PALEOGEOGRAPHY

The paleogeographic setting of northwestern Hunan and eastern Guizhou was summarized by Peng (1992) and Peng and Babcock (2001a). Major regions, defined by sedimentary facies and fauna, are the Yangtze (or South China) Platform, the Jiangnan Slope Belt, and the Jiangnan Basin (Text-figure 1). Together, these regions comprise a carbonate platform-to-basin transition. The Yangtze Platform was located tropically, and received sediments ranging from dolostones, phosphorites, and evaporites to siliciclastics such as black shales, calcareous and carbonaceous shales, siltstones, and marls. Strata representing the Jiangnan Slope Belt include calcareous shales, siltstones, and black shales. The Huaqiao Formation, which is dominated by dark carbonates, was deposited in the Jiangnan Slope Belt. Strata representing the Jiangnan Basin are dominated by dark-gray or black, thinly laminated carbonates.

STRATIGRAPHY Lithostratigraphy Strata representing the upper part of the Cambrian System in northwestern Hunan (Wulingian to lower Hunanian series of South China terminology; Peng and Babcock, 2001) were originally subdivided into four formations (Anonymous, 1974). In ascending order, the units were the Aoxi, Huaqiao, Chefu, and Bitiao formations. Peng and Robison (2000) recognized that differences between the Huaqiao, Chefu, and Bitiao formations were biostratigraphically based, rather than lithostratigraphically based, and expanded the definition of the Huaqiao Formation to include intervals formerly referred to the Chefu and Bitiao formations. The Aoxi Formation is a heterogeneous unit consisting mostly of dark-gray to yellowish gray thinly laminated to medium-bedded dolostone, with interbeds of black shale near the top. The Huaqiao Formation consists mostly of alternating thin beds of dark limestone and argillaceous limestone with interbeds of dolomitic limestone and intercalated light-colored, medium- to thick- bedded carbonate breccia. Carbonate breccia beds are more numerous in the upper part of the Huaqiao Formation at Paibi. Only one such bed occurs at the Wangcun section. The Huaqiao Formation is inferred to represent sedimentation in a slope environment (part of the Jiangnan Slope Belt), and the distribution of breccia beds suggests that the Paibi sections represent deposition higher on the slope apron than does the Wangcun section.

Biostratigraphy Cambrian polymerid and agnostoid trilobites have markedly different paleogeographic distributions. Most polymerid genera are restricted to shelf and slope deposits of individual paleocontinents, whereas many agnostoid genera and species are cosmopolitan in open-marine deposits (Robison, 1976; Peng and Robison, 2000). As a result of the differences in distribution patterns, Robison (1976) proposed that separate sets of zones be developed for polymerid and · 4·

2, . Trilobites hina

, C rovinces iandongian Jiangnan Slope Belt; II Q and Guizhou p in Hunan ) iandongian and Fenghuang area, whereas those dealt with in this book - D 2, +II 1 Cambrian lt (II angnan Slope Be i , 1977; Yang, 1978) are from the Tongren . al

et Zhou in . I, Yangtze Platform; II, J Yang ( , Hunan and Furongian Jiangnan Slope Belt); III, Basin; IV, Zhujiang Region (modified from Peng and Babcock, 2001). distribution of rocks assigned to the Jiangnan Slope Belt facies (

(1963) . al

et Wulingian and Map showing gorova E . near Huayuan and Yongshun figure 1 - from

Text described by are

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agnostoid trilobites, and we continue to advocate that practice. Peng and Robison (2000) documented thoroughly the agnostoid zonation of the Huaqiao Formation. Here, we provide a significantly revised zonation of polymerid trilobites through the stratigraphic interval represented by the Huaqiao Formation. The correlation and relationship between the polymerid and the agnostoid biostratigraphy is shown on Text-figure 2.

Polymerid biostratigraphy Agnostoid biostratigraphy Stage Series System

Shengia quadrata Zone Glyptagnostus reticulatus Zone Chuangia subquadragulata Zone PAIBIAN FURONGIAN

Glyptagnostus stolidotus Zone Liostracina bella Zone Linguagnostus reconditus Zone YOUSHUIAN

Wanshania wanshanensis Zone Proagnostus bulbus Zone

Lejopyge laevigata Zone CAMBRIAN Pianaspis sinensis Zone

WULINGIAN Goniagnostus nathorsti Zone WANGCUNIA

Ptychagnostus punctuosus Zone

Dorypyge richthofeni Zone Ptychagnostus atavus Zone

Unnamed Zone Ptychagnostus gibbus Zone

TAIJIANGIAN

Text-figure 2. Table showing the correlation of polymerid and agnostoid biozones recognized within the Huaqiao Formation of northwestern Hunan, China. Chronostratigraphic names in boldface are applicable globally, and those in plain type are applicable to South China.

Biozones based on polymerid trilobites used here are identified by an eponymous species and characterized by a number of other species. Eponymous species are not necessarily confined to the zones that they represent, and the species do not necessarily have the same stratigraphic ranges outside of northwestern Hunan. Each of the zones defined here is identified by the first appearance of a single species selected for its relatively short stratigraphic range and abundance. The species or genera also have been selected for their relatively wide geographic distributions within Gondwana, wherever practical. The base of each zone is defined by the lowest stratigraphic occurrence of its eponymous species. In most, but not all cases, characterizing species are absent from zones above. The top of each zone is defined by the base of the next overlying zone. In ascending order, six zones are named for the species Dorypyge richthofeni, Pianaspis sinensis, Wanshania wanshanensis, Liostracina bella, Chuangia subquadrangulata, and Shengia quadrata.

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1. Dorypyge richthofeni Zone. The lowest observed occurrences of Dorypyge richthofeni in the Huaqiao Formation are at 3.2 m above the base of the formation in the Paibi section and 33.0 m above the base of the formation in the Wangcun section. Because underlying strata of the Huaqiao and Aoxi formations are poorly fossiliferous, these occurrences may be younger than the first appearances of D. richthofeni elsewhere. In the Wangcun section, a species that characterizes the D. richthofeni Zone, Sudanomocarina sp. cf. S. changi, occurs at 1.2 m above the base of the Huaqiao Formation, so it is inferred that the D. richthofeni Zone extends downward to at least that level. D. richthofeni extends slightly into the lowermost part of the overlying Pianaspis sinensis Zone. Species that characterize the lower part of the D. richthofeni Zone include Huayuanaspis spp., Sudanomocarina sp. cf. S. changi and Maotunia spp. Species that characterize the upper part of the D. richthofeni Zone include Wangcunia wangcunensis, Fuchouia sixinensis, Fuchouia kuruktagensis, Paranomocarella parallela, and Amphoton deois. Paranomocarella fortis ranges from the upper part of the D. richthofeni Zone through much of the overlying Pianaspis sinensis Zone. The base of the D. richthofeni Zone is close to the base of the Ptychagnostus atavus Zone of agnostoid trilobite zonation.

2. Pianaspis sinensis Zone. The lowest observed occurrences of Pianaspis sinensis in the Huaqiao Formation are at 112.6 m above the base of the formation in the Paibi section and 82.1 m above the base of the formation in the Wangcun section. P. sinensis extends through approximately the lower half of the zone. Species that characterize the lower part of the P. sinensis Zone include Lisania yuanjiangensis, Parapianaspis hunanensis, Fuchouia bulba, and Amphoton alceste. Damesellids including Palaeadotes, Blackwelderia, Parablackwelderia, and Paradamesella make their first appearances in the middle to upper part of this zone. Species that characterize and range through much of the P. sinensis Zone include Fuchouia chiai, Fuchouia bulba, and Dorypyge bisulcata. Parablackwelderia jimaensis and Fuchouia oratolimbata range from the upper part of the P. sinensis Zone through much of the Wanshania wanshanensis Zone. Huzhuia paratypica, Palaeadotes hunanensis, Paradamesella peculiaris, and Baojingia subquadrata range from the P. sinensis Zone through the lower part of the Liostracina bella Zone. The base of the Pianaspis sinensis Zone is just below the base of the Goniagnostus nathorsti Zone of agnostoid trilobite zonation.

3. Wanshania wanshanensis Zone. The lowest observed occurrences of Wanshania wanshanensis in the Huaqiao Formation are at 240.5 m above the base of the formation in the Paibi section and 170.0 m above the base of the formation in the Wangcun section. W. wanshanensis extends into about the lower third of the overlying Liostracina bella Zone, although it is relatively uncommon above the W. wanshanensis Zone. Species that characterize the lower part of the W. wanshanensis Zone include Paibiella paibiensis and Dorypyge perconvexalis. Species that characterize the upper part of the W. wanshanensis Zone include Chatiania convexa, Neoglaphyraspis nitida, Damesella hunanensis, and Fenghuangella spp. Damesellids are both abundant and diverse in this zone; they comprise as much as 20% of the polymerid trilobite fossils. Neoanomocarella asiatica, Teinistion posterocostum, Luyanhaoaspis decorosa, Ajrikina hunanensis, Protaitzehoia subquadrata, Monkaspis quadrata, Protaitzehoia granifera, and Buttsia globosa are among the species that range from the W. wanshanensis Zone into the overlying Liostracina bella Zone. Torifera is common in this zone although it ranges into the lower part of the overlying zone. Paraacidaspis hunanica and Proceratopyge (Proceratopyge) fuyangensis range from the W. wanshanensis into the Chuangia subquadrangulata Zone. · 7·

The base of the W. wanshanensis Zone is just below the base of the Proagnostus bulbus Zone.

4. Liostracina bella Zone. The lowest observed occurrences of Liostracina bella in the Huaqiao Formation are at 310.4 m above the base of the formation in the Paibi section and 218.3 m above the base of the formation in the Wangcun section. L. bella has not been observed to extend into the overlying Chuangia subquadrangulata Zone; its last observed occurrence is just below the base of the overlying zone. Species that characterize L. bella Zone include Liostracina bella, Oculishumardia hunania, Chatiania chatianensi, Taihanshania wangcunensis, Paradamesella typica, and Rhyssometopus zhongguoensis. Species that characterize the lower part of the L. bella Zone include Paracoosia huayuanensis, Paibianomocare paibiensis, and Luyanhaoaspis inflata. Damesellids, which range upward from the underlying W. wanshanensis Zone, are present in the L. bella zone, but they are much less numerous than they are in the W. wanshanensis Zone. Species that characterize the upper part of the L. bella Zone include Pseudoyuepingia laochatianensis, Fenghuangella liostracinala, and Meteoraspis sinensis. Placosema bigranulosum ranges from the upper part of the L. bella Zone into the lower part of the overlying Chuangia subquadrangulata Zone, and Shengia trapezia ranges from the top of the L. bella Zone through the overlying C. subquadrangulata Zone. The base of the L. bella Zone is just above the base of the Linguagnostus reconditus Zone of agnostoid trilobite zonation.

5. Chuangia subquadrangulata Zone. The lowest observed occurrence of C. subquadrangulata in the Huaqiao Formation is at 370.6 m above the base of the formation in the Paibi; strata above the L. bella Zone in the Wancun section have not been studied as part of this work. In the Paibi-2 section, C. subquadrangulata is not present, but the first appearance of Chuangia austriaca is used as a proxy for the base of the C. subquadrangulata Zone. C. austriaca first appears at 4.3 m above the base of the Huaqiao Formation in the Paibi-2 section. C. subquadrangulata has not been observed to extend into the overlying Shengia quadrata Zone. Species or subspecies that characterize the C. subquadrangulata Zone include Olenus punctatus, Proceratopyge truncata, Fenghuangella laochatiensis crassa, Prochuangia granulosa, and Stigmatoa yangziensis. The base of the C. subquadrangulata Zone is immediately above the base of the Glyptagnostus reticulatus Zone (just above the base of the Paibian Stage and Furongian Series).

6. Shengia quadrata Zone. The lowest observed occurrence of Shengia quadrata in the Huaqiao Formation is at 72.0 m above the base of the formation in the Paibi-2 section. The eponymous species has not been observed in the Paibi section, and strata above the L. bella Zone in the Wangcun section have not been studied as part of this work However, Peng (1992) discussed S. quadrata and other co-occurring trilobites from northwestern Hunan.

Chronostratigraphy In recent years, a chronostratigraphic scheme for the Cambrian comprising four series subdivisions has been undergoing development. This scheme, which is intended to be applicable globally, has evolved in concert with a developing chronostratigraphic subdivision of the rocks of South China (Peng et al., 1998, 1999, 2000; Peng, 2000, 2003; Peng and Babcock, 2001). The four-part system introduced for South China, which uses widely recognizable biostratigraphic tie-points, represents an improvement over the more traditional three-part subdivision of the Cambrian of the North China Platform, which was based largely on lithostratigraphic units. The scheme used in North China has been applied in South China, but correlations based on it can be · 8·

imprecise (Peng, 2003). Three boundaries relevant to Cambrian chronostratigraphy globally have been ratified: the lower and the upper boundaries of the system, and the base of the uppermost series. The base of the Cambrian System is marked by the first appearance datum (FAD) of the trace fossil Tricophycus pedum (Brasier et al., 1994; Landing, 1994; Gehling et al., 2001). The base of the Ordovician System, which also corresponds to the top of the Cambrian System, is marked by the FAD of the conodont Iapetognathus fluctivagus (Brasier et al., 1994; Cooper et al., 2001). The conterminous base of the uppermost Cambrian series (Furongian) and the lowermost stage of the series (Paibian), which corresponds to the base of the Hunanian Series and Waergangian Stage as used in South China, is defined by the FAD of the agnostoid trilobite Glyptagnostus reticulatus (Peng et al., in press). The Cambrian System of South China comprises four series, including one pre-trilobite series succeeded by three trilobite-dominated series (Peng et al., 1999; Peng and Babcock, 2001). The series are subdivided into a total of nine stages. The base of each Cambrian stage as used in South China is defined at a level coinciding with the FAD of a fossil distributed widely in South China or distributed globally. The chronostatigraphic framework of South China, and the biostratigraphic tie-points currently used to identify boundaries (Peng and Babcock, 2001), is listed below in descending order. The tie-point used to identify the base of each series is the same as that used to identify the base of the lowermost stage of the series. IV, Hunanian Series 9, Taoyuanian Stage (identified by FAD of Irvingella angustilimbata) 8, Waergangian Stage (identified by FAD of Glyptagnostus reticulatus) III, Wulingian Series 7, Youshuian Stage (identified by FAD of Linguagnostus reconditus) 6, Wangcunian Stage (identified by FAD of Ptychagnostus punctuosus) 5, Taijiangian Stage (identified by FAD of Oryctocephalus indicus) II, Qiandongian Series 4, Duyunian Stage (identified by FAD of Arthricocephalus chauveaui) 3, Nangaoan Stage (identified by FAD of trilobites [Tsunyidiscus, Sinodiscus]) I, Diandongian Series 2, Meishucunian Stage (identified by FAD of Paragloborilus subglobosus) 1, Jinningian Stage (identified by FAD of Trichophycus pedum)

The Diandongian Series is a pre-trilobite series, and the Qiandongian, Wulingian, and Hunanian series are based on trilobite-bearing strata. Sections and criteria used for definition of the series and their stages were reviewed by Peng and Babcock (2001). The Diandongian Series and its stages (Jinningian and Meishucunian) are based on sections in eastern Yunnan Province. The Qiandongian Series, the stages of the Qiandongian Series (Nangaoan and Duyunian), and the Taijiangian Stage of the Wulingian Series, are based on sections in eastern Guizhou Province. The other stages of the Wulingian and Hunanian series are based on sections in northwestern Hunan Province. The Wangcunian and Youshuian stages of the Wulingian Series are based on strata in the Wangcun section, from which many of the specimens reported in this work were collected. The lower boundary of the Wangcunian Stage in the Wangcun section is 56.7 m above the base of the Huaqiao Formation, and the lower boundary of the Youshuian Stage in the Wangcun section is 210.5 m above the base of the Huaqiao Formation (Peng et al., 2001e). The FAD of the agnostoid trilobite Ptychagnostus punctuosus, which marks the base of the Wangcunian Stage, occurs slightly below the FAD of the polymerid trilobite Pianaspis sinensis (eponymic species of the P. sinensis Zone). The FAD of Linguagnostus reconditus, which marks the base of the Youshuian Stage, occurs slightly below the FAD of the polymerid trilobite Liostracina bella (eponymic species of the

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L. bella Zone). The conterminous lower boundaries of the Hunanian Series and the Waergangian Stage, and the lower boundary of the Taoyuanian Stage, are based on strata in the section at Waergang, Taoyuan County, northwestern Hunan Province. The base of the Hunanian Series and the base of the Waergangian Stage were defined at the level of the FAD of the agnostoid trilobite Glyptagnostus reticulatus. However, the equivalent position for global chronostratigraphic purposes (conterminous base of the Furongian Series and Paibian Stage) was defined based on the FAD of G. reticulatus in the Paibi section, northwestern Hunan. That position in the Paibi section is 369.06 m above the base of the Huaqiao Formation (Peng et al., 2001a, 2004b, in press). The FAD of G. reticulatus is slightly above the FAD of the polymerid trilobite Chuangia subquadrangulata (eponymic species of the C. subquadrangulata Zone). Just like the section at Paibi, sections in the Wangcun area have great potential for defining or characterizing Cambrian stages. Peng et al. (2004a) reviewed two widely recognizable datum points, the FADs of the cosmopolitan agnostoid trilobites Ptychgnostus punctuosus and Lejopyge laevigata, in the Wangcun section and the Wangcun North section. Rich polymerid trilobite faunas in these sections enhance the importance of these sections for global chronostratigraphic correlation.

MEASURED SECTIONS

Specimens forming the basis of this work were collected from three measured sections in the Huaqiao Formation of northwestern Hunan. The sections lie on opposite limbs of a large undulating syncline, the Liexi-Zhuitun Syncline, which strikes to the north-northeast (Text-figure 3). The Liexi-Zhuitun syncline exposes mostly Cambrian and Ordovician formations at the surface. Two measured sections (Paibi and Paibi-2), on the southwestern flank of the syncline, are located near the village of Paibi, Huayuan County, Hunan (Text-figure 1). The third measured section, on the northeastern flank of the syncline, is about 4 km southeast of Wangcun, along the Wangcun to Luoyixi road, along the north side of the Fengtan Reservoir on the Youshui River (Text-figure 1). The Paibi-1 and Wangcun sections represent long, essentially uninterrupted intervals through the upper Aoxi and Huaqiao formations. The Paibi-2 section is a much shorter interval through the Huaqiao Formation. Dark to medium gray carbonate beds constitute the background sedimentation pattern in the Huaqiao Formation in both the Paibi and Wangcun areas. Allochthonous carbonate debris beds occur in the Paibi and Paibi-2 sections but they do not appear to interrupt the stratigraphic appearance of trilobite species (Peng et al., 2004). The Wangcun section is almost completely lacking in carbonate debris beds. The sections near Paibi have a considerably greater diversity of polymerid trilobite species than does the section near Wangcun. The diversity of agnostoid trilobite species is nearly the same in both areas. Measured sections near Paibi and Wangcun, Hunan, China, are described below and accompanied by columnar stratigraphic sections showing the ranges of polymerid trilobite species (Text-figures 4-6). In the following descriptions, numbered beds are indicated at the far left of each bed description. Bed 1 represents the stratigraphically lowest position, and beds are numbered successively in ascending order. Within each bed description collection numbers are indicated. Numbers preceded by a P or W refer to levels in meters above the base of the Huaqiao Formation in the Paibi and the Wangcun sections, respectively. Numbers preceded by a Pb refers to level in meters above an arbitrary zero point (at the base of the massive breccia in the basal part of Bed 58) in the Paibi-2 section. Numbers within parentheses are alternate field collection numbers. Numbers preceeded by HP, Gs, and Gr refer to collections of trilobites, and numbers preceded by PC refer to collections of conodonts.

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Text-figure 3. Geological map of northwestern Hunan, China, showing locations of measured stratigraphic sections near Paibi and Wangcun (modified from Peng and Robison, 2000).

Paibi Section (Text-figure 4) This well exposed section is located near the village of Sixincun. It was orignally measured by Chen Yongan and his colleagues of the 405 Geological Team, Jishou, northwestern Hunan, in 1981. The measured section is on the north side of the Jishou-Huayuan highway (part of the Chinese National Highway 319), about 35 km north of Jishou and 35 km south of Huayuan. Beginning just west of Sixincun, the section extends eastward approximately 1.7 km to the foot of a small hill north of Sixincun, about 1 km nortwest of Paibi. The measured interval is composed almost completely of carbonates. Exposures reveal the uppermost strata of the Aoxi Formation, which consist of dolostone intercalated with black shale, overlain by limestones (lime mudstones, wackestones, packstones, and some intercalated carbonate debris beds) of the the Huaqiao Formation. The Huaqiao Formation includes strata representing the Dorypyge richthofeni through the Chuangia subquadrangulata biozones (equivalent to the upper part of the Ptychagnostus atavus through the lower part of the Glyptagnostus reticulatus biozones in terms of agnostoid trilobite zonation). The section contains the Global Standard Stratotype-section and Point for the base of Furongian Series, which is the uppermost series of the Cambrian System, and the base of the Paibian Stage, which is the lowermost stage of the series (Peng et al., 2004).

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Text-figure 4. Zonation and observed stratigraphic distribution of non-agnostoid species in the Robison (2000) for the agnostoid stratigraphic distribution and zonation

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Huaqiao Formation of the Paibi section near Paibi, Huayuan, northwestern Hunan; see Peng and of the same section. Their agnostoid zonation is adopted in this figure.

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Huaqiao Formation 41. Medium gray to dark-gray, thin-bedded packstone intercalated with medium gray, thin bedded grainstone containing small siliceous concretions (with diameters of 0.5-1.0 cm). 385.50-388.5 m 40. Medium gray, thick-bedded grainstone, with a layer of thick-bedded limestone breccia at base and top. 381-385.5 m P383.5: Chuangia subquadrangulata, Placosema bigranulosum sp. nov.; agnostoid Glyptagnostus reticulatus. 39. Medium gray to dark-gray, thin-bedded packstone and grainstone containing small siliceous concretions (with diameters of 0.5-1.0 cm). 378.2-381 m P379: Placosema bigranulosum sp. nov. P378.3: agnostoids Peratagnostus obsoletus, Pseudagnostus josepha. P378.25 (HP31): polymerids Afghanocare truncatum, Baikadamaspis paibiensis sp. nov., Fenghuangella laochatianensis crassa, Paraacidaspis hunanica, Proceratopyge (Proceratopyge) fenghwangensis, Proceratopyge (Proceratopyge) truncata, Prochuangia granulosa, Prochuangia cf. P. leiocephala, Prochuangia linicispinata, Pseudomapania cylindrica, Shengia wannanensis, Stigmatoa yangziensis; agnostoid Glyptagnostus reticulatus. 38. Dark-gray, thin-bedded packstone intercalated with several layers of dark-gray, striped grainstone and a single layer of limestone breccia. This bed is divided into 4 subbeds (total thickness 7.44 m). 38d. Dark-gray, thin-bedded packstone, intercalated with a single layer of medium gray grainstone. 376.32-378 .2 m P376.4 ( HP30d ): polymerids Paibianomocare paibiensis gen. et sp. nov., P. ( Pro- ceratopyge) fenghwangensis. P376.22 (Gr6): polymerids Acmarhachis typicalis, Chuangia subquadrangulata, P. (Proceratopyge) fenghwangensis; agnostoids Glyptagnostus reticulatus, Peratagnostus obsoletus; conodont Furnishina furnishi. 38c. Dark-gray, thin-bedded packstone, intercalated with two layers of dark, thin-bedded grainstone and a single layer of medium gray, thin-bedded limestone breccia (0.25 m thick). 372.62-376.32 m P375.9: agnostoid Glyptagnostus reticulatus. P375.22 (Gr5, PC59): agnostoids Agnostus inexpectans, Glyptagnostus reticulatus, Peratagnostus obsoletus, Pseudagnostus josepha; conodonts Westergaardodina bicuspidata, Muellerodus sp. cf. M. pomeranensis. P375.15: polymerids Chuangia subquadrangulata, Placosema bigranulosum, Pro- chuangia cf. P. leiocephala. P375.0: polymerids Placosema bigranulosum, P. (Proceratopyge) fenghwangensis; Placosema bigranulosum sp. nov.; agnostoids Peratagnostus obsoletus, Pse- udagnostus josepha. P374.9 (HP30c): polymerids Afghanocare truncatum, Chuangia subquadrangulata, Dorypyge perconvexalis, Huzhuia curvata sp. nov., Placosema bigranulosum, Proceratopyge (Proceratopyge) truncata, Prochuangia leiocephala, Prochuangia cf. P. leiocephala; agnostoids Glyptagnostus reticulatus, Agnostus inexpectans, Peratagnostus obsoletus, Pseudagnostus josepha. P374.76 (PC56): conodont Furnishina sp. cf. F. alata. P373.50 (PC43): conodonts Huayuanodontus tricornis, Furnishina furnishi, F. sp. cf. F. alata. P373.22 (Gr4): polymerid Baikadamaspis paibiensis; agnostoid Glyptagnostus

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