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Geological Society of Australia ABSTRACTS Number 84 SOUTH AUSTRALIA 2006 XI INTERNATIONAL CONFERENCE OF THE CAMBRIAN STAGE SUBDIVISION WORKING GROUP Editor: J. B. Jago

South Australia, August 14-24,2006

Geological Society of Australia ABSTRACTS Number 84 SOUTH AUSTRALIA 2006 XI INTERNATIONAL CONFERENCE OF THE CAMBRIAN STAGE SUBDIVISION WORKING GROUP Editor: J. B. Jago

South Australia, August 14-24,2006

The XI International Conference of the Cambrian Stage Subdivision Working Group gratefully acknowledges the support of the following organizations Geological Society of Australia International Subcommission on Cambrian Stratigraphy School of Natural and Built Environments, University of South Australia Department of Primary Industries and Resources, South Australia Beach Petroleum Limited

XI International Conference of the Cambrian Stage Subdivision Working Group committee Jim Jago, University of South Australia Elinor Alexander, Primary Industry and Resources, South Australia Glenn Brock, Macquarie University Barry Cooper, Primary Industry and Resources, South Australia Robert Dart, University of Adelaide Margaret Fuller, South Australian Museum Colin Gatehouse, Consulting geologist Jim Gehling, South Australian Museum John Laurie, Geoscience Australia John Paterson, Macquarie University Zang Wenlong, Primary Industry and Resources, South Australia

Copies of this publication may be obtained from Geological Society of Austraha Incorporated, Suite 706, 301 George Street, Sydney, NSW 2000 Australia or on-line at www.shop.gsa.orE.aii

ISSN Number 0729 01IX

SOUTH AUSTRALIA 2006 PLENARY SESSION PROGRAMME, THURSDAY AUGUST 17, 2006, PIRSA 9.00 - 9. 20 Welcome. Chairs: Shanchi Peng and Linda McCollum 9.20 - 9.40. Landing, E., Westrop, S. R. & Keppie, J. D. Cambrian-Ordovician boundary interval in Mexican northwest Gondwana - the Tinu Formatio of Oaxaca State. 9. 40 - 10.00. Geyer, G. & Buschmann, B. A new earliest Middle Cambrian faunule from Saxony (Germany) and its bearing on the tectonostratgraphic history of the Saxothuringian domain. 10. 00 - 10.20. Ahlberg, P., Axheimer, N., Eriksson, M. E., Schmitz, B. & Terfelt, F. High-resolution trilobite biostratigraphy and carbon isotope stratigraphy of the middle Cambrian-lower Furongian of Baltica. 10. 20 - 10. 40. Fletcher, T. P., Some trilobite ranges in the hicksii and davidis zones ifissuspunctuosus zones). 10. 40 - 11.10 BREAK Chairs: Malgosia Moczydlowska and Per Ahlberg 11.10 - 11.30. Peng Shanchi, Babcock, L., Lin Huanling, Zuo Jingxun, Zhu Xuejian, Zhou Chaunming, Yang Xianfeng, Qi Yueping & Li Quan. Potential Global Standard Stratotype-sections (GSSPs) for the unnamed Cambrian Stage 7 and Stage 9 at Luoyixi, NW Hunan and Duibian, W Zhejiang, South China. 11.30 - 11.50 Lin Jih-Pai. On the origin of some Cambrian arthropods. 11. 50 - 12.10 Garcia-Bellido, D. C. Paleoaeoscolecid worms from the Cambrian of Spain: Burgess Shale and Orsten-type preservation. 12.10 - 12.30 Wotte, T. The Lower-Middle Cambrian fauna from the Cantabrian Mountains (north-western Spain): palaeoenvironmental and palaeobiogeographical considerations. 12. 30 - 12.50 Skovsted, C. B. Dailyaitia sclerites from the Arrowie Basin - unexpected taxonomic diversity and morphological complexity of a Lower Cambrian problematicum. 12. 50 - 1.40 LUNCH Chairs: Duck Choi and Jim Jago 1.40 - 2.00 Brock, G. A., Skovsted, C. B., Holmer, L. E. & Paterson, J. R. A preliminary brachiopod biostratigraphy for the Lower Cambrian of the Flinders Ranges, South Australia. 2.00 - 2.20 Paterson, 3.R& Brock, G. A. A new trilobite assemblage from the Pararaia bunyerooensis Zone (Early Cambrian, South Australia) and its biostratigraphic significance. 2.20 - 2. 40 Zhu Maoyan, Zhang Junming, Yang Aihua, Li Guoxiang & Yang Xinglian. The first series of the Cambrian of South China: Subdivision and correlation. 2.40 - 3.00 Li Guoxiang, Zhu Maoyan, Zhang Junming & M. Steiner. Bio- and carbon isotope stratigraphy of the lower Cambrian in eastern Yunnan and the subdivision of the first series of the Cambrian. 3.00 - 3.20 Sun Weiguo. The Chengjiang fauna: A unique window into the Cambrian Explosion. 3. 2 0 - 3 . 40. BREAK

Chairs: Gerd Geyer and Ed Landing 3.40 - 4.00 M. Moczydlowska & W. L. Zang. Biodiversity of Early Cambrian acritarchs and their life cycle. 4. 00 - 4.20 Perejon A., Moreno-Eiris E., Fernandez-Remolar, D., Garcia-Bellido, D. C & Menendez S. Biostratigraphic proposal based on archaeocyaths and small shelly fossils from the southern margin of Gondwana and a tentative correlation. 4.20 - 4.40 Lee S. B., Lee, D. C. & Choi, D. K. The trilobite family Missisquoiidae Hupe, 1955: systematics, evolution and paleogeography. 4.40 - 5.00 McCollum, L. & Sundberg, F. Distribution of agnostids and oryctocephalids within the Laurentian Delamaran Stage. 5.00 - 5.20 Luo Kunli & Hollingsworth, J. S. The sequence and geochemistry of the Precambrian-Cambrian boundary interval in the southern Qinling Mountains, central China.

POSTERS Luo Kunli Quartzite and chert breccias, Precambrian-Cambrian boundary interval. North China Plate. Parkh, T. Y., Han, Z. Z., Bai, Z. Q. & Choi, D. K. The Middle Cambrian trilobite Cyclolorenzella Kobayashi 1960 and related genera from Korea and China: morphometric analysis and taxonomic revision. Smith, M. Predatory drill holes in Lapworthella fasciculata from the Wilkawillina Limestone, Wilkawillina Gorge, Flinders Ranges, South Australia. Sohn, J. W. & Choi, D. K. Revised Middle to Upper Cambrian trilobite biostratigraphy of the Sesong and Hwajeol formations, Taebaek Group, Taebaeksan Basin, Korea. Topper T. P. The identity of the Mongolitulus animal and documentation of small sahelly fossils from the upper Memmema Formation at Donkey Bore Syncline, Central Flinders Ranges, South Australia. Zhu Xuejian & Peng Shanchi On Shergoldia Zhang & Jell, 1987 (Trilobita) and the Tsinaniidae.

PLENARY SESSION PROGRAMME, MONDAY AUGUST 21, 2006, LEIGH CREEK Chair: Jim Jago 7.30 - 8.00 Cooper, B. J. & Jago. J. B. History of Cambrian studies in South Australia (1836-1990) with particular reference to the biostratigraphy. BREAK FOR REFRESHMENTS 8.40 - 9.00 Hollingsworth J. S. Early Cambrian trilobites in western Laurentia suggest that a thick unfossiliferous siliciclastic sequence correlates with thin, fossiliferous carbonates in Siberia. 9.20 - 9.40 Perejon A., Moreno-Eiris E. & Menendez S. Archaeocyathan biostratigraphy and palaeobiogeography of the southwestern margin of Gondwana. 9.40-10.00 Babcock, L. E. & Ciampaglio, C. N. Frondlike fossil from the Cambrian of Georgia, USA: another holdover from the Ediacaran biota.

HIGH-RESOLUTION TRILOBITE BIOSTRATIGRAPHY AND CARBON ISOTOPE STRATIGRAPHY OF THE MIDDLE CAMBRIAN-LOWER FURONGIAN OF BALTICA Per Ahlberg, Niklas Axheimer, Mats E. Eriksson, Birger Schmitz, & Fredrik Terfelt Department of Geology, GeoBiosphere Science Centre, Lund University, Solvegatan 12, SE223 62 Lund, Sweden During the past two decades, attention has been paid to the potential of carbon isotopes in the global stratigraphic correlation of Cambrian strata. In the uppermost middle Cambrian-lower Furongian, a significant positive shift in values o f - 4 % o , referred to as the Steptoean positive carbon isotope excursion (SPICE), has been documented from a wide range of regions, including South China, Kazakhstan, Australia, and the United States. The onset of the SPICE coincides with significant biotic turnovers and verifies the largely agnostoid-based intercontinental correlations in the middle Cambrian-Furongian transitional interval. Although known from several palaeocontinents, this excursion has not been confirmed previously from Baltica. A new core drilling at Andramm in Scania (Skane), southernmost Sweden, penetrated a c. 29 m thick, highly condensed succession of lower Furongian-middle Cambrian dark grey or black shales (alum shales) with subordinate limestone beds and lenses. The core contains a continuous stratigraphical succession from the lower Ptychagnostus atavus Zone (middle Cambrian) to the lower Parabolina brevispina Subzone (Furongian). Carbon isotope analyses on organic matter recovered from 51 alum shale samples show, for the first time, that the SPICE can also be identified in Baltica. The curve obtained from Andramm is calibrated against a high-resolution trilobite biostratigraphy and spans an interval from the middle Lejopyge laevigata Zone into the lower P. brevispina Subzone. With small fluctuations, the values become increasingly positive through the L. laevigata and Agnostuspisiformis zones, and reach peak values in the Olenus wahlenbergi and O. attenuatus subzones of the lower Furongian (2-4 m above the first appearance of Glyptagnostus reticulatus). Thereafter the values gradually decrease to reach significantly lower values in the upper O. scanicus Subzone and the lower P. brevispina Subzone. These post-excursion values roughly coincide with the occurrence of the cosmopolitan trilobite Irvingella in Scandinavia. The maximum amplitude of the documented excursion is approximately half of that recorded in other regions. This may be explained by the fact that the analyses were made on organic matter as opposed to whole-rock carbonate analyses in other regions. The stratigraphic fit of the recorded excursion, however, leaves little doubt that it is the SPICE.

FRONDLIKE FOSSIL FROM THE CAMBRIAN OF GEORGIA, USA: ANOTHER HOLDOVER FROM THE EDIACARAN BIOTA Loren E. Babcock^ & Charles N. Ciampaglio^ ^School of Earth Sciences, The Ohio State University, Columbus, Ohio 43210, USA ^Department of Geological Sciences, Wright State University, Lake Campus, 7600, State Route 703, Celina, Ohio 45822, USA Siliceous concretions in the Conasauga Formation (Cambrian) of the Coosa River Valley, northwestern Georgia and northeastern Alabama, USA, contain a moderately diverse assemblage of biomineralized and non-biomineralized organisms, plus trace fossils. In addition to polymerid and agnostoid trilobites characteristic of the Laurentian open shelf, biomineralizing organisms occurring in the concretions or in shaly intervals include inarticulate brachiopods, echinoderm ossicles, hyolithids, hyolithelHds, salterellids, chancelloriids, Scenella, Helcionella, Pelagiella, and the hexactinellid sponge Brooksella. Non-biomineralized fossils include graptolites, appendages of the trilobite Glyphaspis, limb fragments of Anomalocaris, and a vermiform animal. Trace fossils preserved in the concretions include Palaeophycus and coprolites. The Conasauga Formation includes strata ranging from the upper part of the Olenellus Zone (Dyeran Stage as used in Laurentia) to the Glyptagnostus reticulatus Zone (Furongian Series, Paibian Stage). The specimen reported here is associated with trilobites indicative of the Bolaspidella Zone (Marjuman Stage as used in Laurentia). One siliceous concretion from the Conasauga Formation of Floyd County, Georgia, contains an exceptionally preserved frondlike fossil. The specimen preserves only the distal end of the frond and is weathered. Nonetheless, the gross morphology is distinct, and it shares broad similarities to two frondlike fossils previously reported from the Cambrian (Thaumaptilon from the Burgess Shale Biota of British Columbia, Canada, and Priscapennamarina from the Chengjiang Biota of Yunnan, China). These frondlike taxa, and the new one from Georgia, bear strong similarities and probable relationships to Charnia, Charniodiscus, and other frondlike organisms from the Ediacaran Period. Tentatively, all these taxa are interpreted as pennatulacean cnidarians, a group whose evolutionary history thus extends from the Ediacaran, across the Neoproterozoic-Cambrian boundary, to the Holocene. The new frondlike fossil from Georgia is preserved in a siliceous concretion by means of siliceous infilHng. As such, it appears to retain original convexity. The specimen has a narrow, tapering, leaflike morphology distally, with rather broad cushionlike branches extending disto-laterally from a broad but weakly defined central axis. The branches appear connected to the axis. Branches show ringlike partitions suggestive of chambers that in life housed zooids. The basal end of the organism is not preserved, and the total length is not known. Comparison with Charnia, Charniodiscus, and Thaumaptilon suggests a total length exceeding 15 cm. To retain its convexity, the new frondlike fossil must have undergone rapid silicification, probably mediated by the activities of a microbial consortium that quickly formed a biofilm around the dead host. The source of colloidal silica needed to precipitate the concretion is inferred to be the dissolution of opaline spicules of co-occurring organisms, most notably Brooksella sponges, which occur in great abundance in the Conasauga Formation.

A PRELIMINARY BRACHIOPOD BIOSTRATIGRAPHY FOR THE LOWER CAMBRIAN OF THE FLINDERS RANGES, SOUTH AUSTRALIA Glenn A. Brock\ Christian B. Skovsted\ Lars E. Holmer^ i& John R. Paterson^ ^Centre for Ecostratigraphy cS: Palaeobiology, Dept. of Earth & Planetary Sciences, Macquarie University, NSW, Australia 2109. ^Uppsala University, Department of Earth Sciences, Palaeobiology, Norbyvdgen 22, SE-752 36 Uppsala, Sweden. Detailed sampling of key Lower Cambrian successions in eastern South Australia (Stuart Shelf, Flinders Ranges and Yorke Peninsula) combined with investigation of previously unstudied shelly fossil collections belonging to the late Brian Daily has revealed a plethora of exquisitely preserved, previously undocumented, organophosphatic and calciate brachiopods from this region. These new assemblages provide new data for a preliminary biostratigraphic "biozonation" for the Lower Cambrian succession of South Australian based on brachiopods. Whilst much work needs to be completed, four distinct brachiopod biozone assemblages can be recognised in the Lower Cambrian succession of South Australia. The oldest assemblage, dominated by the cryptotretid Askepasma occurs in pre-trilobitic (mid Atdabanian) successions of the Wilkawillina and Wirrapowie limestones. The top of the Askepasma assemblage zone is broadly equivalent with the Abadiella huoi trilobite zone (late Atdabanian) and best represented in the Flinders Ranges, but also occurs in the Stansbury Basin and on the Stuart Shelf. The succeeding assemblages, best defined in the Stansbury Basin, are early Botoman in age and characterised by Eoobolus, Minlatonia, Eodicellomus and Kyrshabaktella. This is followed by a mid-late Botoman assemblage with Eoobolus, Karathele and Curdus. The youngest (Toyonian) assemblage, best represented in the Wirrealpa Limestone is characterised by the first acrotretid (Vandalotreta) in the South Australian sequence, along with Karathele and the calciate taxon Trematobolus wirrialpensis.

HISTORY OF CAMBRIAN STUDIES IN SOUTH AUSTRALIA (1836-1990) WITH PARTICULAR REFERENCE TO THE BIOSTRATIGRAPHY B. J. Cooper^ & J. B. Jago^ ^Department of Primary Industries and Resources of South Australia, GPO Box 1671, Adelaide, South Australia 5001, Australia (Cooper.Barry@saugov.sa.govMu) ^School of Natural and Built Environments, University of South Australia, Mawson Lakes, South Australia 5095, Australia (jim.jago@unisa.eduMu) Although some early South Australian geologists used the term Cambrian and reported possible fossils, the first definite Cambrian fossils were found by Tepper (1879) from near Ardrossan on Yorke Peninsula. These included the first Cambrian trilobites to be described in Australia, by Woodard (1884) as Dolichometopus tatei and Conocephalites australis (now Pararaia tatei and Yorkella australis); Woodard assigned a Lower Silurian age. The Cambrian age of the faunas was first recognised by Etheridge (1890) who described archaeocyatha from both Yorke Penisula and the Flinders Ranges. Ralph Tate, professor of Natural Sciences at Adelaide University, described several new taxa in 1892. Walter Howchin, who succeeded Tate at Adelaide University in 1902, concentrated on unravelling the Cambrian stratigraphic succession, but Howchin's Cambrian included a lot of what is now known to be Neoproterozoic, although earlier, Howchin (1897) had recognised archaeocyatha on Fleurieu Peninsula for the first time. Taylor (1910) published a major monograph on archaeocyatha, including the superbly preserved material from near the Ajax Mine, Beltana. Etheridge (1919) summarized the known information on Australian Cambrian trilobites. In the 1920s and 1930s significant contributions to Cambrian stratigraphy were made by Douglas Mawson and Cecil Madigan from Adelaide University. Another significant contribution in the 1930s was by the redoubtable Robert Bedford of Kyancutta, a remote farming community on Yorke Peninsula. Bedford, who fell foul of the scientific establishment, independently published a series of monographs on archaeocyatha in the Memoirs of the Kyancutta Museum. However, neither Taylor nor Bedford attempted any biostratigraphy. R. C. Sprigg estabhshed the Geological Mapping branch within the Geological Survey of South Australia in 1946. This was the start of an excellent programme of systematic mapping that continued for several decades. Sprigg discovered the Ediacara fauna at Ediacara, trilobites on Kangaroo Island and recognised the Cambrian age of the Kanmantoo Group on Fleurieu Peninsula. Glaessner (1979) described part of the lagerstatte from Big Gully, Kangaroo Island. R. Dalgamo reviewed and summarized the Cambrian stratigraphy of the Flinders Ranges (Dalgamo 1964). Walter (1967) produced the first biostratigraphy based on archaeocyathan taxonomy. H. Wopfner of the Geological Survey produced a facies analysis (Wopfner 1970) of the Cambrian of the Flinders Ranges as part of a petroleum exploration programme. Brian Daily (1931-1986) was the first person to make the Cambrian stratigraphy of South Australia his research specialty. Daily supervised a series of honours and postgraduate students who made a major contribution to the understanding of the Cambrian of the Flinders Ranges. As part of his PhD, Daily (1956) erected 12 faunal assemblages, which for many years were the basis of Lower Cambrian correlations between Australia and other continents. Daily's students, P. G. Haslett(1975) and P. S. Moore(1980), plus B. Youngs of the Geological Survey produced the first detailed sedimentological studies of the Cambrian of the Flinders Ranges. Another of Daily's students, David Gravestock, did his PhD studies on the archaeocyatha from the lower part of the South Australian Cambrian succession. This work of Gravestock (1984), plus earlier studies from the classic Ajax Mine localities by Fran9oise

Debrenne (1969, 1974a, 1974b), saw the start of modem taxonomic studies of the South Australian Cambrian faunas. These were continued by Bengtson et al (1990) who provided detailed taxonomic descriptions of trilobites, small shelly fossils and others. Jell in Bengtson et al (1990) erected four trilobite zones. References BENGTSON S., CONWAY MORRIS S., COOPER B. J., JELL P.A. & RUNNEGAR B.N. 1990. Early Cambrian shelly fossils from South AustraHa. Association of Australasian Palaeontologists Memoir 9, 1-364. DAILY, B. 1956. The Cambrian in South Australia. 91-47 in Rodgers, J. (ed.), El Sistema Cambrico, supaleogeografiya y elproblema su base, 20^^ Intemational Geological Congress Mexico, 1956, volume 2. DALGARNO C. R., 1964. Lower Cambrian stratigraphy of the Fhnders Ranges. Transactions of the Royal Society of South Australia 94, 21-48. DEBRENNE F. 1969. Lower Cambrian Archaeocyatha from the Ajax Mine, Beltana, South Austraha. British Museum of Natural History. Bulletin (Geology) 17, 297-376. DEBRENNE F. 1974a. Les archeocyathes irreguliers d'Ajax Mine (Cambrien inferieur, Australie du Sud). Bulletin du Museum National d'Histoire Naturelle, sciences de la terre 33, 185-258 DEBRENNE F. 1974b. Anatomie et systematique des archeocyathes reguliers sans plancher d'Ajax Mine (Cambrien inferieur, Australie du Sud). Geobios 7, 91-138. ETHERIDGE R. L. 1890. On some Australian species of the family Archaeocyathinae. Transactions of the Royal Society of South Australia 13, 10-22. ETHERIDGE R. L. 1919. The trilobites of Australia and Tasmania. Transactions of the Royal Society of South Australia 43, 373-393. GLAESSNER M. F. 1979. Lower Cambrian Crustacea and annelid worms from Kangaroo Island, South Austraha. Alcheringa 3, 21-31. GRAVESTOCK D. I. 1984. Archaeocyatha from lower parts of the Cambrian carbonate sequence in South Australia. Association of Australasian Palaeontologists Memoir 2, 1-139. HASLETT P. G. 1975. The Woodendinna Dolomite and Wirrapowie Limestone—two new Lower Cambrian formations. Flinders Ranges, South Australia. Transactions of the Royal Society of South Australia 99,211-220. HOWCHIN W. 1897. On the occurrence of Lower Cambrian fossils in the Mount Lofty Ranges. Transactions of the Royal Society of South Australia 21, 74-86. MOORE P. S. 1980. Stratigraphy and depositional environments of the Billy Creek Formation (Cambrian) east of the Flinders Ranges, South Australia. Transactions of the Royal Society of South Australia 104, 117-132. TATE R. 1892. The Cambrian fossils of South Australia. Transactions of the Royal Society of South Australia 15, 183-189. TAYLOR T. G. 1910. The Archaeocyathinae from the Cambrian of South Australia with an account of the morphology and affinities of the whole class. Memoirs of the Royal Society of South Australia 2, 55-188. TEPPER J. G. O. 1879. Introduction to the cliffs and rocks at Ardrossan. Transactions of the Philosophical Society of South Australia 2, 71-79. WALTER M. R. 1967. Archaeocyatha and the biostratigraphy of the Lower Cambrian Hawker Group. Journal of the Geological Society of Australia 14, 139-152. WOODARD H. 1884. Note on the remains of trilobites from South Australia. Geological Magazine, new series, Decade 5, 1, 342-344. WOPFNER H. 1970. Early Cambrian palaeogeography, Frome Embayment, South Australia. American Association of Petroleum Geologists. Bulletin, 54, 2395-2409. YOUNGS B. C. 1977. The sedimentology of the Cambrian Wirrealpa and Aroona Creek Limestones. South Australia. Geological Survey. Bulletin, 47.

SOME TRILOBITE RANGES IN THE PARADOXIDID ZONES OF hicksii AND davidis Terence P. Fletcher

Bowmont Cottage, East Links, Road, Dunbar,East Lothian, Scotland, EH42 ILT The paradoxidid zones of hicksii and davidis incorporate the more-widely recognized agnostoid fissus-atavus to punctuosus zones and contain a suite of polymerid trilobites commonly associated with paradoxidid sequences, notably those of New Brunswick (Hayes & Howell 1937), Newfoundland (Hutchinson 1962), Wales (Hicks & Salter 1866; Salter & Hicks 1869; Nicholas 1916), England (Illing 1916), Scandinavia (Westergard 1946) and the Siberian sections along the Lena, Judoma and Maya rivers (Yegorova et al 1982). Due to the absence in some sections of the relevant agnostoid zonal taxa, correlations have been based upon recognition of such polymerids. However, certain anomalous ranges are evident in faunal lists from the above-mentioned countries. At a previous group meeting of the Cambrian Stage Subdivision Working Group, Geyer (2001) outlined the numerous pitfalls of correlation, in particular those effected by dubious taxonomy and quality of the collections. Although a chronological agnostoid succession of first appearances of Ptychagnostus gibbus-Tomagnostus fissus and Ptychagnostus atavus-Hypagnostus parvifrons-Ptychagnostus punctuosus is apparent (Westergard 1946; Rowell et al 1982), a comparable succession of polymerids is, for the most part, much less succinct. In my short talk, some misidentifications and certain synonymous taxa affecting correlation of late-paradoxidid sequences will be highlighted. Comparing fossil distribution in the Manuels River Formation of south-eastern Newfoundland with contemporary paradoxidid sequences may provide a good illustration. The fossil assemblages of four Newfoundland sections at Manuels (Howell 1925), Highland Cove (Hutchinson 1962, Section 6, p. 131-132), McLeod Point (Hutchinson 1962, Section 8, p. 134) and Deep Cove (Fletcher 2006) are markedly different and appear to be due to very subtle lithological differences affecting preservation and, therefore, the quality of collecting. References FLETCHER T. P. 2006. Geology of the Cape St. Mary's Peninsula, southwest Avalon Peninsula, Newfoundland. Geological Survey Branch, Department of Natural Resources, Govemment of Newfoundland. Report 2006-2. GEYER G. 2001. Correlation in the Cambrian: puzzling facts and wrong concepts? In Cambrian System of South China. Peng, S., Babcock, L. E. & Zhu, M. (eds.). Palaeoworld 13, 87-98. Press of University of Science and Technology of China. 3 lOp. HAYES A. O. & HOWELL B. F. 1937. Geology of Saint John, New Brunswick. Geological Society

ofAmerica, Special Papers, Number 5. 146p.

HICKS H. & SALTER J. W. 1866. Report on further researches in the Lmgw/a-Flags of South Wales. Report of the British Association for the Advancement of Science for 1865, 281-286. HOWELL B. F. 1925. The faunas of the Cambrian Paradoxides Beds at Manuels, Newfoundland.

Bulletins ofAmerican Paleontology, 11, Number 43, 140p. HUTCHINSON R. D. 1962. Cambrian stratigraphy and trilobite faunas of southeastem Newfoundland. Geological Survey of Canada, Bulletin 88, 156p, 25 pis. ILLING V. C. 1916. The Paradoxidian Fauna of a part of the Stockingford Shales. Quarterly Journal of the Geological Society ofLondon 71, 386-450. NICHOLAS T. C. 1916. Notes on the trilobite fauna of the Middle Cambrian of St. Tudwal's Peninsula (Camarvonshire). Quarterly Journal of the Geological Society ofLondon 71, 83-143.

ROWELL A. J., ROBISON R. A. & STRICKLAND D. K. 1982. Aspects of Cambrian agnostoid phylogeny and chronocorrelation. Journal ofPaleontology 56, 161-182. SALTER J. W. & HICKS H. 1869. On some fossils from the 'Menevian Group'. Quarterly Journal of

the Geological Society ofLondon 25, 51-57.

WESTERGARD A. H. 1946. Agnostidea of the Middle Cambrian of Sweden. Sveriges Geologiska Undersokning, Series C, 477, 141p. YEGOROVA L. I., SHABANOV YU. YA., PEGEL T. V., SAVITSKY V. E., SUCHOV S. S. & TCHERNYSHEVA N. E. 1982. The type locality of the Mayan Stage. Transactions of the Academy of Sciences of the U.S.S.S.R., Ministry of Geology, 8, 146p. [in Russian].

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PALAEOSCOLECID WORMS FROM THE CAMBRIAN OF SPAIN: BURGESS SHALE-TYPE AND ORSTEN-TYPE PRESERVATION" Diego C. Garcia-Bellido Departamento de Paleontologia. Instituto de Geologia Econdmica (CSIC-UCM). Facultad de Ciencias Geoldgicas. Jose Antonio Novais, 2. 28040-Madrid. Spain. Palaeoscolecidans are a Lower Palaeozoic group of vermiform animals of millimetric to decimetric size, which can be identified by the presence of an annulated cuticle with rows of phosphatic microelements. These worms have been known since the nineteenth century (Ulrich 1878), but it was not until the mid-eighties that they were allocated under their own class (Conway Morris & Robison 1986). The taxonomic assignment of the group has been under debate for some time, having been associated with the annelids, the nematomorphs, the chaetognaths and the priapulids. The idea that the Palaeoscolecida is located near or within the Priapulida appears to be receiving wider support. Palaeoscolecid fossil remains in Cambrian rocks have been described from Australia, USA, China, Spain, United Kingdom, Siberia, Greenland, Turkey, Sardinia, Kazhakstan, Iran and Antarctica. The fossils of these animals can be preserved in at least three different ways. One is known as soft-bodied, or Burgess Shale-type, preservation. Here, the remains are preserved by the interaction of the original organic carbonaceous material and the clay minerals of the matrix, producing thin compressions of the organisms including their soft tissues (e.g. Conway Morris & Robison 1986). A second way is Orsten-type preservation, where the external organic cuticle of the animals has been secondarily phosphatized and is now recovered as three-dimensional microscopic cuticle fragments with phosphatic elements, and occasionally other structures, preserved in their original arrangement (e.g. Mtiller & Hinz-Schallreuter 1993). Finally, the microelements are also found as SSF (Small Shelly Fossils), in the form of isolated sclerites or tubercles, and these have been usually described under the parataxa Hadimopanella, Milaculum, Kaimenella and Utahphospha (e.g. Hinz et al 1990). All three types of preservation have now been recognized from the Cambrian of Spain. Isolated sclerites assigned to Hadimopanella were described from the Middle Cambrian member of the Lancara Formation in NW Spain by Van den Boogaard (1983) and FemandezRemolar (2001). A large (c. 8 cm long) soft-bodied fossil was described by Conway Morris & Robison (1986), and a small specimen (c. 3 cm long) by Gamez Vintaned (1995). They were collected in Murero (Zaragoza), and both were assigned to Palaeoscolex cf P. ratcliffei Robison 1969. Here two new specimens are presented, a c. 22 cm long specimen of Palaeoscolex cf P. antiquus Glaessner 1979, and a fragment of Palaeoscolex cf P. ratcliffei, also from the Middle Cambrian Murero Formation in NE Spain. Acid etching of carbonate samples associated with archaeocyath reef mounds from the Lower Cambrian Pedroche Formation in SW Spain has recently produced some fragments which possibly represent Orsten-type preservation of palaeoscolecid cuticles. References CONWAY MORRIS S. & ROBISON R. A. 1986. Middle Cambrian priapulids and other soft-bodied fossils from Utah and Spain. The University of Kansas Paleontological Contributions Papers 117, 122.

FERNANDEZ-REMOLAR D. C. 2001. Nota sobre la distribucion estratigrafica de Hadimopanella Gedik, 1977 (microscleritos de paleoscolecidos), en el Cambrico. Revista Espahola de Micropaleontologia 33 (2), 113-121. GAMEZ VINTANED J. A. 1995. Nuevo hallazgo de un anelido (?) paleoscolecido en el Cambrico Medio de Murero (Cadena Iberica Occidental, NE de Espana), pp. 205-218. In: J.A. Gamez Vintaned & E. Linan (eds.) La Expansion de la Vida en el Cambrico, Homenaje al Profesor Klaus Sdzuy. Institucion "Femando El Catolico", Zaragoza, 272 pp.

GLAESSNER M. F. 1979. Lower Cambrian Crustacea and annelid worms from Kangaroo Island, South Australia. Alcheringa 5, 21-31. HINZ I., KRAFT P., MERGE M. & MULLER K. J. 1990. The problematic Hadimopanella, Kaimenella, Milaculum and Utahphospha identified as sclerites of Palaeoscolecida. Lethaia 23, 217221. MULLER K. J. & HINZ-SCHALLREUTER, I. 1993. Palaeoscolecid worms from the Middle Cambrian of Australia. Palaeontology 36, 549-592. ROBISON R. A. 1969. Annelids from the Middle Cambrian Spence Shale of Utah. Journal of Paleontology^?^, 1169-1173. ULRICH E. O. 1878. Observations on fossil annelids, and descriptions of some new forms. Journal of the Cincinatti Society of Natural History 1, 87-91. VAN DEN BOOGAARD M. 1983. The occurrence oi Hadimopanella oezgueli Gedik in the Lancara Formation in NW Spain. Proceedings of the Koninklijke Nederlandse Akademie van Wettenschappen Series B 331-341.

A NEW EARLIEST MIDDLE CAMBRIAN FAUNULE FROM SAXONY (GERMANY) AND ITS BEARING ON THE TECTONOSTRATIGRAPHIC HISTORY OF THE SAXOTHURINGIAN DOMAIN Gerd Geyer^ & Bernd Buschmann^

Institutfur Paldontologie, Bayerische Julius-Maximilians-Universitdt Wurzburg, Germany Institut fur Geologic, TUBergakademie Freiberg, Freiberg, Germany Fossiliferous Cambrian rocks are rare in Central Europe but quite well preserved in Lusatia and northern Saxony. Although the mode of preservation is quite different between the two regions, the lithologies suggest a common depositional domain that also indicates a common faunal province. Cambrian rocks of the Delitzsch-Torgau-Doberlug Synclinory in northern Saxony and adjacent areas do not represent a continuous succession. Deposition during the Cambrian sedimentation starts after a stratigraphic and structural gap (Cadomian unconformity) with local conglomerates, followed by Early Cambrian shallow marine carbonates and minor siliciclastics. The Lower Cambrian consists of shallow marine carbonates and siliciclastics with common calcimicrobial biogenetic carbonates that contain archaeocyaths. Bilaterian skeletal fossils are rare and do not allow an exact stratigraphic position of the strata. A late Early Cambrian (early Banian) age is plausible. The Middle Cambrian (Arenzhain Group, with Trobitz and Delitzsch Formations) is represented by siliciclastics with minor carbonate intercalations. The Trobitz Formation, dominated by quartzitic sandstones and alternating with micaceous claystones is early but not earliest Middle Cambrian in age as indicated by comparatively rich fossil associations with trilobites, inarticulate brachiopods, and hyoliths. The trilobites indicate a stratigraphic level equivalent to the Iberian Paradoxides (Eccaparadoxides) sdzuyi biozone, corresponding to the middle to upper Agdzian sensu Geyer & Landing (2004). The overlying Delitzsch Formation consists of dominating quartzarenitic sandstones alternating with claystones. As for the Trobitz Formation, the faunas are dominated by trilobites, inarticulate brachiopods, and hyoliths. Two different stratigraphic levels can be distinguished. The older level has an early Middle Cambrian age equivalent to the younger fauna of the Trobitz Formation. A younger fauna includes the trilobites, brachiopods, and helcionelloid molluscs. Most trilobites, such as Badulesia tenera, represent a relatively narrow stratigraphic interval of mid Middle Cambrian age (early Caesaraugustan). Unfortunately, the transition from Lower to Middle Cambrian strata is unknown. This led to the assumption that a significant stratigraphic gap between the strata of the two series is present in this area. However, a newly identified faunal assemblage reduces this supposed hiatus considerably so that it may indeed represent a gap created by incomplete biostratigraphic data rather than physical. The fossils were identified from a drill-core from west of Doberlug-Kirchhain and south of Herzberg (drill-core 1209/78). This recently identified assemblage yields with trilobites such as Protolenus (Hupeolenus) aff termierelloides, Cambrunicornia n. sp., and two other trilobite species as well as inarticulate brachiopods (the obolellid Trematobolus cf splendidus., an acrothelid, and an unidentified acrotretoid). Despite the relative paucity of the fauna due to the limited amount of material from the drill-core, the preservation is remarkably good with only faint distortion of the specimens and partly a preservation of shells. The faunule features the lowest Middle Cambrian upper Hupeolenus and/or lowest Cephalopyge zones (lower Agdzian in the West 14

Gondwanan standard). It therefore represents not only the oldest known Middle Cambrian from the Lusatian/Saxonian segment of the Saxothuringian but also the oldest Middle Cambrian fauna known from the Saxothuringian domain in general. All of the species have near relatives in coeval strata of the typical West Gondwanan realm, particularly in southern Morocco, from where Hupeolenus, Cambrunicornia, and Trematobolus splendidus were first described. The fossils were found in thin limestone beds within fine to medium-grained siliciclastics. The lithology and facies differ to some extent from those of the Trobitz Formation so that it probably represents a lithostratigraphic unit underlying the Trobitz Formation which has not yet been identified from other parts of the Delitzsch-Torgau-Doberlug Synclinory. Remarkably, the thin limestone layers which yield the macrofossils appear to indicate a transgressive development and thus parallel the environmental development seen in the coeval strata of the Jbel Wawrmast Formation in southern Morocco which marks the termination of the regressional events at the Lower-Middle Cambrian boundary interval.

EARLY CAMBRIAN TRILOBITES IN WESTERN LAURENTIA SUGGEST THAT A THICK UNFOSSILIFEROUS SILICICLASTIC SEQUENCE CORRELATES WITH THIN, FOSSILIFEROUS CARBONATES IN SIBERIA J. Stewart Hollingsworth

Institute for Cambrian Studies, 729 25 Road, Grand Junction, Colorado 81505, USA. (stewhoUiMcioI. com.) Efforts to define stages within the Lower Cambrian are severely hampered by endemism of the early trilobite faunas. Excluding certain eodiscids, there are virtually no cosmopolitan trilobite species until late in the Early Cambrian, and in most regions polymerid trilobites predate the eodiscids. The areas of most concern, when attempting to define the first occurrence of trilobites as a stage or series boundary indicator, are Siberia, western Gondwana (Morocco and Spain), and Laurentia. The earliest trilobite occurrences in other palaeocontinents currently appear to be younger than the faunas of these areas. In western Nevada the base of the Cambrian occurs at or near the base of the Upper Member of the Deep Spring Formation (Corsetti & Hagadom 2003). Upper Member siliciclastics preserve a variety of trace fossils including Treptichnus pedum and probable arthropod scratches, but no small shelly fossils have been reported from the carbonate beds of the Upper Member. At the top of the Deep Spring Formation, there is a distinct flooding surface at the base of the Andrews Mountain Member of the Campito Formation which is dark grey very fine sandstone and siltstone with rare trace fossils, apparently deposited in relatively deep water. This major boundary probably correlates with the base of the Sauk Sequence identified in the coarser, shallow-water siHciclastics of the Wood Canyon Formation (Cooper & Fedo 1995). One interpretation would suggest that this flooding event is correlative with the base of the black shales of the Niutitang Formation in South China (Steiner et al. 2001) and thereby possibly equivalent to the sequence boundary near the base of the Tommotian Stage in Siberia (Zhuravlev 1996). The Andrews Mountain Member is about 800 m of dark grey siliciclastics, often devoid of trace fossils. Near the top, two cycles beginning with light coloured transgressive quartzite unit have abundant and diverse traces with hyoliths in the lower unit and a varied metazoan (brachiopods, trilobites, and hyoliths) fauna in the upper interval which ranges from 58 to nearly 100 m in thickness. Recent work on this interval in western Nevada has developed more data on the early trilobite occurrences. Above this interval for about 40 m, the siliciclastics are devoid of body fossils although trace fossils are common and the sediments are bioturbated. In the upper fossiliferous interval, the lowest trilobite, lacking genal spines and with wide-spaced ocular lobes thus resembling Repinaella explicata is soon joined by a second form also lacking genal spines, but with the ocular lobes located close to the conical glabella, and resembling Repinaella sibirica. However, neither form is clearly conspecific with the Siberian forms. Another trilobite with long, widely-directed genal spines, perhaps most resembling Eofallotaspis, becomes common in the middle of the fossiliferous interval. Other forms may emerge as these trilobites are studied in detail. All appear to be olenellines, lacking facial sutures. These trilobites are rare; less than seventy partial or complete cephala have been found in about 25 days of searching. Other than in small bioclastic calcareous nodules and on a couple of siltstone slabs, the trilobites are isolated in quartzitic sandstone or occasionally in siltstone. Preservation is generally poor. Obolellid brachiopods, representing perhaps several species, are at least twice as common as the trilobites in this interval. These trilobite forms suggest that western Laurentia had a closer relationship with Siberia than with western Gondwana, at least initially. The beginning of this fossiliferous interval appears to correspond with the second trilobite zone in the Atdabanian Stage of Siberia. In the

Esmeralda Basin, all of the Tommotian and the earliest zone of the Atdabanian are represented by unfossiliferous and relatively dysoxic arenaceous marine sediments. References COOPER J. D. & FEDO C. M. 1995. Base of the Sauk Sequence in the southem Great Basin and Eastem Mojave Desert. Geological Society of America, Abstracts with Programs, 27(6) A-331. CORSETTI F. A. & HAG ADORN J. W. 2003. The Precambrian transition in the southem Great Basin, USA. The Sedimentary Record 1, 4-8. STEINER M., WALLIS E., ERDTMANN B-D., ZHAO Y. L. & YANG R. D. 2001. Submarinehydrothermal exhalative ore layers in black shales from South China and associated fossils - insights into a Lower Cambrian facies and bio-evolution. Paleogeography, Paleoclimatology, Paleoecology 169, 165-191. ZHURAVLEV A. YU. 1996. Early Cambrian sequence biostratigrapy on the Siberian Platform. In Linan, E., Gamez Vintaned, J. A., and Gonzalo, R. (eds.) II Field Conference of the Cambrian Stage Subdivision Working Groups, Spain, 13-21 September 1996, Field Trip Guide and Abstracts: 123.

CAMBRIAN-ORDOVICIAN BOUNDARY INTERVAL IN MEXICAN NORTHWEST GONDWANA—THE TINU FORMATION OF OAXACA STATE. Ed Landing^ Stephen R. Westrop^ & John D. Keppie^ ^New York State Museum, Madison Avenue, Albany, New York 12230, USA. (elandin^(w/naiL nvsed.ôv) Ôklahoma Museum of Natural History and School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73072, USA (swestrop@ou.edu) Înstituto de Geologia, Universidad National Automona de Mexico, Ciudad Universitaria, 04510 Coyoacan, D. F., Mexico (Duncan@servidor.unam.mx) The Tinu Formation, the oldest fossiliferous unit in southern Mexico, occurs in several inliers along a N-S belt in central Oaxaca State. The thin (ca. 70 m) Tinu Formation nonconformably overlies middle Proterozoic (ca. 1 Ga), high-grade metamorphics and intmsives. This passive margin lithosome is unconformably overlain by the Cretaceous or Tertiary or overthrust by the lower Carboniferous. Although traditionally referred to the lowest Ordovician (Tremadocian), restudy of the Tinu shows that it includes a condensed, uppermost Cambrian lower member (to 13 m) and a lower, but not lowermost, Ordovician upper member (to 60 m). The limestone-rich lower member represents a wave-dominated shelf with echinoderm hash-trilobite fragment-intraclast pebble beds with firmgrounds and dunes in the south (Rio Salinas area). This facies changes into an upper slope facies with carbonate-clast debris flows and distal tempestites in the north (Santiago Ixtaltepec area). These shell hash-dominated limestones are a non-Laurentian, non-tropical, temperate lithofacies with abundant, low-diversity conodonts that record two or, more probably, three eustatic onlaps in the lower and uppermost Cordylodus proavus Chron (terminal Cambrian). After Cambrian-Ordovician boundary offlap (recorded by a thin conglomerate or a phosphate horizon), strong middle Tremadocian eustatic onlap brought dendroid graptolite-bearing and olenid trilobite-bearing, dysoxic mudstone across the lower-upper member unconformity. Shoaling into the high-stand facies again led to deposition of temperate shell-hash limestones with upper lower Tremadocian (Hunnebergian Stage) conodonts and macrofaunas. Highenergy, wave-dominated sandstones with orthid brachiopods are the highest units of the Tinu. Although a "Grenvillian" basement and the facies and biotas of Carboniferous and younger units of the Oaxaquia terrane are "North American," the Lower Paleozoic of this terrane is non-Laurentian, non-Avalonian, and best considered deposited on the southern margin of the Rhetic Ocean.

THE TRILOBITE FAMILY MISSISQUOIIDAE HUPE, 1955: SYSTEMATICS, EVOLUTION AND PALAEOGEOGRAPHY Seung-bae Lee\ Dong-Chan Lee^ & Duck K. Choi^ ^ School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Korea (shlee77(dlsrnLac,kr; dk.choi(d),smLac,kr) ^Department of Museum, Daejeon Health Sciences College, Daejeon 300-711, Korea The family Missisquoiidae is an important member among the Late Cambrian and Early Ordovician trilobites. Eleven genera have been allocated to this family including Hardy a, Tasmanocephalus, Parakoldinioidia, Pseudokoldinioidia, Missisquoia, Lunacrania, Macroculites, Rhamphopyge, Paranumia, Tangshanaspis, and Fuzhouwania. However, owing to the range of morphological variation, various opinions have been expressed on the systematics of the Missisquoiidae. The genus Missisquoia Shaw, 1951 has long been employed as an index taxon for defining the base of the Ordovician in North America. Missisquoia had been exclusively known to occur in Laurentia until Missisquoia perpetis Zhou and Zhang 1985 was reported in North China. The recognition of Missisquoia in North China apparently enhanced the stratigraphic value of Missisquoia for correlation of eastern Gondwana with Laurentia. However, subsequent examination of the material reveals that the specimens assigned to M. perpetis are morphologically distinct from the typical Missisquoia in Laurentia and can be better accommodated within Pseuokoldinioidia Endo 1944. This study attempts to review the systematics of the Missisquoiidae and to explore its probable evolutionary lineage and implications for palaeobiogeography. Missisquoiid trilobites and related taxa are phenetically compared and accordingly four cranidial and pygidial morphotypes are recognized within the missisquoiids: i.e., Missisquoia, Tangshanaspis, Parakoldinioidia, and Pseudokoldinioidia morphotypes. Hardyia, Lunacrania and Tasmanocephalus are not readily applicable into this scheme. Of great interest is the palaeogeographical and stratigraphical distribution of these morphotypes. The Missisquoia morphotype occur exclusively in Laurentia, while the Pseudokoldinioidia and Parakoldinioidia morphotypes are confined to Gondwana. In contrast, the Tangshanaspis morphotype represented by Tangshanaspis zhaogezhuangensis, Missisquoia depressa and M. mackenziensis is found both in Gondwana and in Laurentia. Hardyia and Lunacrania occur only in Laurentia and Tasmanocephalus is restricted to Australia. The oldest genus, Parakoldinioidia, first appeared in the Iverian Stage of Australia and subsequently dispersed into the east Gondwana region and may have given rise to Pseudokoldinioidia or Tangshanaspis. In the late Late Cambrian, Pseudokoldinioidia became a more important member of the family than Parakoldinioidia in Gondwana, while Tangshanaspis is closely related to Parakoldinioidia in morphology than Pseudokoldinioidia which overlaps with Tangshanaspis in stratigraphic range. In the mean time, it is interesting to see that the Tangshanaspis morphotype occurs in the uppermost Cambrian of Laurentia. At present it is premature to suggest whether the taxa belonging to the Tangshanaspis morphotype from Laurentia and Gondwana form a phylogenetic clade or if they simply represent an example of homeomorphs. The youngest Missisquoia is widespread in Laurentia across the Cambrian-Ordovician boundary interval and displays a wide range of morphological variation. There is no concrete evidence to determine if Missisquoia has been derived from the Laurentian Tangshanaspis or other genera. Even more complicated is that all of the species assigned to Missisquoia in Laurentia may not belong to the same genus. Nevertheless, one of the conclusions deduced from the present analysis is that the Gondwanan and Laurentian missisquoiids are likely to have evolved along separate lineages and hence great caution should be exercised in palaeogeographic interpretations based on these data.

BIO- AND CARBON ISOTOPE STRATIGRAPHY OF THE LOWER CAMBRIAN IN EASTERN YUNNAN AND THE SUBDIVISION OF THE SERIES OF THE CAMBRIAN Guoxiang L i \ Maoyan Zhu\ Junming Zhang^ & Michael Steiner^ ^LPS, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences ^Technical University Berlin, Sekr. ACK14, Ackerstrasse 71-76, 13355 Berlin, Germany The eastern Yunnan Province, located in the southwest of the Yangtze Platform is recognized as one of the most important regions for studying lower Cambrian stratigraphy and the Precambrian-Cambrian boundary. The pretrilobitic Cambrian (i.e., Cambrian Series 1) strata are well exposed there and contain abundant small shelly fossils (SSF), which provide index fossils for biozonation of the pre-trilobitic Cambrian and for subdividing the Series 1 (i.e.. Stage 1-Stage 2 boundary). The pretrilobitic Cambrian rock units in the region include, in ascending order, the Zhongyicun and Dahai members, and the Shiyantou Formation. The Zhongyicun Member consists mainly of phosphorites and dolomites, the Dahai Member mainly of limestones, while the Shiyantou Member consists mainly of siliciclastic rocks but contains many limestone interbeds and lenses. The carbonate or carbonate-bearing stratigraphic successions also provide opportunities for analyzing secular variations of carbon isotopes, which has been proven to be a powerful tool for stratigraphic correlation, through the pre-trilobitic Cambrian interval. The pre-trilobitic Cambrian stratigraphic interval in South China has been traditionally taken as the Meishucunian Stage, which was based on the stratotypes in eastern Yunnan. Based on the SSF record, four biozones have been recognized for the Meishucunian Stage, in ascending order, as follows: Anabarites trisulcatus - Protohertzina anabarica Assemblage Zone, Paragloborilus subglobosus - Purella squamulosa Assemblage Zone (formerly the Paragloborilus subglobosus - Siphogonuchites triangularis Assemblage Zone, but recently revised by Steiner and others), Watsonella crosbyi (=Heraultipegma yunnanensis) Assemblage Zone, and the Sinosachites flabelliformis - Tannuolina zhangwentangi Assemblage Zone. Although SSFs are highly provincial and many of them are not even useful for interregional correlation, some taxa, such as Watsonella crosbyi, Anabarites trisulcatus, Protohertzina anabarica and Protohertzina unguliformis, may exhibit a worldwide distribution and enable a biostratigraphic correlation of the pre-trilobitic sequences between different blocks. Furthermore, the FAD of Watsonella crosbyi can potentially be an important marker for defining the Stage 1 - Stage 2 boundary. The profile across the uppermost Neoproterozoic and the pretrilobitic Cambrian interval in eastern Yunnan exhibits the following features: (1) a sharp negative shift in the lower Daibu Member (Upper Neoproterozoic, underlying the Zhongyicun Member), (2) a gradual shift towards positive values from the upper Daibu Member to the top of the Zhongyicun Member, (3) a major positive excursion spanning the upper Dahai Member, and (4) the Shiyantou Formation showing negative 5 ^C values with a sharp fall near the boundary between the Dahai Member and the Shiyantou Formation. These variations are useful for regional and global correlation. In particular, the major positive excursion spanning the upper Dahai Member may be significant in the subdivision of Cambrian Series 1.

ON THE ORIGIN OF SOME CAMBRIAN ARTHROPODS Jih-Pai Lin Department of Geological Sciences, The Ohio State University, 125 South Oval Mall, Columbus, OH43210, USA. (Lin.542@osu.edu) The Cambrian is a unique time period that encompasses the origination of most modem phyla, including the Arthropoda. Although the evolutionary relationships among Cambrian arthropods are not well understood, due to the limitations of conventional parsimony analyses, they are critical for establishing the timing of origination and the nature of early divergence in Arthropoda. Two case studies are outlined here. First, Lin et al. (2006) hypothesized that parvancorinomorphs, including Ediacaran Parvancorina and Cambrian descendants, such as Primicaris and Skania, are the closest sister group to primitive arachnomorphs, such as Naraoia and calcified trilobites. Furthermore, Parvancorinomorpha is one of the few arthropod groups ranging across the mass extinction event at the traditional Lower-Middle Cambrian boundary that had led to extinction of redlichiid and olenellid trilobites. Intercratonic, biostratigraphic correlation shows that the occurrences of Primicaris and Skania coincide with at least three Cambrian trilobite evolutionary faunas known as biomeres. Thus, parvancorinomorphs coevolved with Cambrian trilobite biomeres and they may share the common ancestry of basic stocks with trilobites as hypothesized in Lin et al. (2006). The second case study is on the divergence of Crustacea and Chelicerata. According to the underlying assumption of parsimony analyses, members of a monophyletic group share the same common ancestry. Thus, if the Arthropoda is a monophyletic group, the Crustacea and Chelicerata should share a common ancestor with a mixture of genetic traits that give rise to groups of descendants with synapomorphies. In a cladogram, the common ancestry is compressed to a node. However, the key questions of understanding divergence are the following. Could a common ancestor be preserved in the fossil record? Could a primitive species bear a mixture of significant morphologic characters that are unique (or become synapomorphies) in separate branches of descendants? There are plenty of enigmatic arthropods in the Cambrian that are potential candidates to help better understand these issues. For example, Burgessia bears a simple dorso-ventrally flattened exoskeleton and primitive biramous appendages. It is unique in that the dorsal morphology is most similar to chelicerates (e.g., Limulus), and the ventral morphology is similar to other coeval arachnomorphs leading to crustaceans. This is a classic example of heterobathmy (see Bechly 2005). Without knowing the proper outgroup for comparison, the character polarity cannot be resolved easily when enigmatic arthropods, such as Burgessia, are included in parsimony analyses. Thus, there must be new approaches for phylogenetic study in order to fully grasp the evolutionary meaning of Cambrian arthropods. References BECHLY G. 1995. Glossary of phylogenetic systematics with a critic of mainstream cladism. Available online at: liitp://www.natiu'kyindemusei^ bw.de/stuttgart/projekte/bemstein/odonata/glossary.htm (accessed 26 May, 2006). LIN J. P., GON S. M., Ill, GEHLING J. G., ZHAO Y. L., ZHANG X. L., HU S. X., YUAN J. L., YU M. Y. & PENG J. 2006. A Parvancorina-\ikQ arthropod from Cambrian strata of South China.

Historical Biology 18, 33-45.

QUARTZITE, CHERT AND BRECCIA AT THE PRECAMBRIANCAMBRIAN BOUNDARY INTERVAL IN THE NORTH CHINA PLATE Luo Kunli Institute of Geographical Sciences and Natural Resource Research, Chinese Academy of Sciences, llA Datun Road, Anwai, Beijing 100101, People's Republic of China (luokl@igsnrr. ac. cn) A bed of breccia ranging from 0.2 to 6 m thick occurs just above the quartzite and chert bed and below the Manto Formation in the Precambrian-Cambrian boundary interval in the North China Plate. Approximately 10-30 m of quartzite (in the west of the North China Plate) and 0.5-4 m of flint stone (in the central part of the North China Plate) occur below the breccia and immediately above the Palaeoproterzoic granite-gneiss. In turn, the breccia is overlain by 20 to 280 m of redlichiid-bearing, upper Lower Cambrian strata (Longwangmiaoan Stage) in the lower part of the Manto Formation (Xiang & Zhu 1999). The quartzite and chert bed can be found at most localities on the North China Plate, including Shaanxi, Shanxi, Shandong, Hebei and northern Jiangsu provinces. This bed is thicker in the western part of the North China Plate. Everywhere it unconformably rests on an erosion surface developed on Palaeoproterozoic rocks. The breccia bed just above the quartzite and chert is thicker in the central part of the North China Plate than it is in the west. The lithologic character of the breccias differs from area to area. In the west, the breccia is mainly chert, yellow shale and quartzite as well as some granite-gneiss blocks. In the east and central part of the North China Plate are mainly dolomite breccias (clasts ranging from 5 to 40 cm in diameter). In Shandong, there is minor chert in the breccia. West of Beijing, chert occurs at the base of the breccia and dolomite occurs in the upper part of the breccia bed. Above the breccia is the redlichiid-bearing lower part of the Manto Formation (Xiang & Zhu 1999), which consists mainly of purple and yellow shale and is overlain conformably by the Maozhuang Formation. The lower part of the Manto Formation contains the Weijiaspis and Redlichia murakamii trilobite zones. The quartzite unit represents the initial Phanerozoic marine transgression on the North China Plate. The overlying breccia may be interpreted as the redeposited weathered material representing the disconformable base of the Manto Formation. Alternatively, the breccia may represent a unique event bed of unknown origin. Similar geochemical characteristics suggest that the quartzite and chert unit of the North China Plate correlates with the Zabriskie Quartzite (Dyeran Stage) of western Laurentia.

THE STRATIGRAPHY AND GEOCHEMISTRY OF THE PRECAMBRIANCAMBRIAN BOUNDARY INTERVAL, SOUTHERN QINLING MOUNTAINS, CENTRAL CHINA Luo Kunli^ & J. Stewart Hollingsworth^ ^Institute of Geographical Sciences and Natural Resource Research, Chinese Academy of Sciences, llA Datun Road, Anwai, Beijing 100101, People's Republic of China (luokl@igsnrr. ac. cn) ^Institute for Cambrian Studies, 729 25 Road, Grand Junction, CO 81505, USA fstewhoIICqlaoI. com) The Lower Cambrian stratigraphy of the Yangtze Platform (eastern Yunnan, Hunan, Guizhou, Sichuan and southern Shaanxi provinces) and of the North China Plate is well studied. Less is known, however, of the Lower Cambrian rocks of the Kunlun-Qinling Fold Belt. About 300 rock samples were collected from five Lower Cambrian sections on south Qingling Mountain to study the geochemical character of the Precambrian-Cambrian boundary interval. The results show that the stratigraphic and geochemical character of the Lower Cambrian in the south Qingling Mountain is different from both the Yangtze Platform and the North China Plate. The Precambrian-Cambrian boundary interval at south Qinling Mountain contains four rock units. The lowermost unit comprises 20 to 70 m of thick-bedded dolomite, dolomitic limestone and siliceous dolomite. This overlies a thick interval of Late Proterozoic volcanic rocks. The upper part contains small shelly fossils: Archaeooides sp., Protohertzsina sp., Chancelloria sp. and hyolithids. The second unit comprises about 20 m of phosphatic dolomite and limestone, variably silicified and brecciated. These units correlate well with the Dengying Formation of the Yangtze Platform. The third and fourth units are included in the Lujiaping Formation. The third unit comprises nearly 300 m of black carbonaceous, siliceous shale with phosphate nodules at the base. This unit contains four recognizable cycles and includes interbeds of witherite (BaC03) and stone coal. Anomalous values of V, Ag and Mo are present. In the upper part, there is a 20 to 30 m siliceous dolomite breccia and somewhat higher a 20 m bed of basic volcanic tuff. No fossils have been recognized in this unit. The fourth rock unit is 82 m of dark slate and light grey (green weathering) sericitized schist and silty slate. Fragments of trilobites and brachiopods have been found in the upper part of this shaly unit. The Lujiaping Formation correlates with the Zhujiaqing, Shiyantou and Yu'anshan formations in Yunnan Province, the Niutitang Formation in Guizhou Province, the Kuanchuanpu Formation in Ningqiang County, southern Shaanxi Province, and the Shuijimgtuo Formation in Hubei Province. The main difference between the Lower Cambrian of south Qinling Mountain and of the Yangtze Platform is the great thickness of the black chert and associated siliceous and carbonaceous shales in the Lujiaping Formation. Geochemical results show elevated levels of selenium associated with carbonaceous beds throughout this interval.

SOUTITCriTNA

SmBRlA

Kunluii-Qi«li»g

Fold Zone Yimiiaii Province (Zhu, 1999) Stages Stage

Fon-nntion.

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LidioJogy

Fauna

Guiziiou

Hitiiaii

Province

i. i

QinJing Mountain, South

{Wang, 1984)

Shaanxi

•{liin-bed-dcd tioloniile and ljn:icstonc

Balang Fni, Jianzhuba Fm.

Minghsingssu ^Fm.

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Ziyang, Daba area, SoiUii

Shale

Liitwstonc

Quarfz Canglangpu Fm.

Black-gray arn1 eray •

saiKl'itoT>e 3nd conglomerate

Chtjjjyjang Fauna

green shuJe a

Uglii gray scriciiizcd scl iisi and sdiy sUut;.

n\?xk and !>rny sliak. cavbtmaceous sbak- and fine sandsione

Tfilobile fragments

{•"irsi trilobite, PurahiKhidtc

Black

B!at:V shulvr

and Mo. Ni

with Mo, Ni

suJfules

suHides

Siliceous schist interbcdcd Willi iitJni. vVitheritf bed!i, and anomalous A§ and My vslitci,. 73 m siliceous doiomitc breecfa at base.

Biack ^Oiaic with Mo, Ni SiiiikJt;:,

Upper pai-t si 1 Upper panray siltstone, biotxirbated

Tauituoiina Zone Tha-c cycles of black siliceous rock intert^cddod witb black carbon-rich siliceous s>Kjle, iimeslone and doion^ tc. Cycles arc about 40 m.

Cliert and phosphoiile Bbck ^ilnshak with plrosphatic congiomcrnle at base

Anoxic Event Small shcUy extiaction

DaKai N!b.

{'iiuspiiulic di>k>mi(e and }j;nestonc with blpck siSiccous s)i;ilc. Small slK-nyfossifs.

Purm'hhorilus-

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rhospliorites

j'^hdiiphoriicb

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silictvii's rock and dolomite

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Dengying Fm

i Dengying i Fm.

absent

Dengying Fnv

DISTRIBUTION OF AGNOSTOIDS AND ORYCTOCEPHALIDS WITHIN THE LAURENTIAN DELAMARAN STAGE Linda B. McCollum^ & Frederick A. Sundberg^ ^Geology Department, 130 Science Building, Eastern Washington University, Cheney, WA 99004, USA (lmccollum@mailewu.edu) ^821 E, Pine Lane, Show Low, AZ 85901, USA. (freddeb85@cableone.net) The stratigraphic occurrence and geographic distribution of agnostoid and oryctocephalid trilobites within the Laurentian Delamaran Stage may contribute to the establishment of a GSSP below the candidate Ptychagnostus atavus Biozone. These two groups of trilobites evolved rapidly, and although none have global distribution, some species have been found in open marine lithofacies on two or more Cambrian continents. Therefore, they constitute the most likely taxa for a candidate GSSP. The base of the Delamaran Stage occurs immediately above the olenellid extinction, coincident with the traditional Laurentian Middle Cambrian series boundary. The Delamaran Stage encompasses three genus-based biozones, the Plagiura-Poliella, the Albertella, and the Glossopleura Faunizones of Lochman-Balk & Wilson (1958). Subsequent study of the lower portion of the Delamaran Stage in the type area of the southern Great Basin resulted in species-based biozonation, which includes the recognition of two post-olenellid and prePlagiura-Poliella faunas assigned to the Eokochaspis nodosa and Amecephalus arrojosensis biozones of Sundberg & McCollum (2000), replacement of the generic based PlagiuraPoliella Faunizone with the Poliella denticulata Biozone of Sundberg & McCollum (2003), and the division of the Albertella Faunizone into a XOWQV Albertellina aspinosa subbiozone overlain by the Albertella highlandensis subbiozone of Eddy & McCollum (1998). Oryctocephalids occur throughout the Delamaran Stage in the outer carbonate platform and basinal lithofacies. The lack of a comprehensive study of this group world wide hinders any attempt at ascertaining the geographic distribution of species, although recent taxonomic work has shown that Oryctocephalus indicus has a wide distribution through the circumPacific region. Oryctocephalus indicus, a candidate species for a GSSP, occurs near the base of the Poliella denticulata Biozone. The Peronopsis bonnerensis Assemblage Zone of Robison (1976) is the only occurrence of agnostoid trilobites within the Delamaran Stage. This low diversity agnostoid fauna includes Peronopsis bonnerensis, Peronopsis brighamensis, rare Ptychagnostus praecurrens, and several species of eodiscids, along with the highest occurrence of Albertella. Ptychagnostus praecurrens, which is designated as a biozone in Scandinavia, is also present at the top of the Albertella Biozone, and could be considered a candidate for a GSSP. Knowledge of the stratigraphic range of agnostoids and oryctocephalids within the Delamaran Stage is restricted geographically. A complete biostratigraphic section through the Delamaran Stage is present within the type area of the southern Great Basin, and possibly within the southern Canadian Rocky Mountains. There are no reported faunas between the Olenellus and Glossopleura biozones in the Atlantic region of eastern Laurentia. References EDDY J. D. & MCCOLLUM L. B. 1998. Early Middle CdLmhrim Albertella Biozone trilobites of the Pioche Shale, southeastem Nevada. Journal of Paleontology 72, 864-887. LOCHMAN-BALK C. & WILSON J. L. 1958. Cambrian biostratigraphy in North America. Journal of Paleontology 32, 312-350. ROBISON R. A. 1976. Middle Cambrian trilobite biostratigraphy of the Great Basin. In Robison R. A. & Rowell A. J. (eds), Paleontology and depositional environments: Cambrian of westem North America. Brigham Young University Geology Studies 23 (2), 39-50.

SUNDBERG F. A. & MCCOLLUM L. B. 2000. Ptychopariid trilobites of the Lower-Middle Cambrian boundary interval, Pioche Shale, southeastern Nevada. Journal of Paleontology 74, 604-630. SUNDBERG F. A. & MCCOLLUM L. B. 2003. Trilobites of the lower Middle Cambrian Poliella denticulata Biozone (new) of southeastern Nevada. Journal of Paleontology 77, 331-359.

BIODIVERSITY AND LIFE CYCLE OF THE EARLY CAMBRIAN ACRITARCHS Malgorzata Moczydlowska^ & Wenlong Zang^

^Uppsala University, Earth Sciences, Palaeobiology, Norbyvdgen 22, SE-752 36 Uppsala, Sweden (malgo. vidal@pal uu. se) 2 ^Geological Survey, Department ofPrimary Industries and Resources of South Australia, 101 Grenfell Street, Adelaide, SA 5001, Australia (zang.wen-long@saugov.sa.govMu) Diversification of the early Cambrian acritarchs, recorded by several radiation and extinction events, is recognized on a global scale and used for biostratigraphic zonation. The radiation of acritarchs was a part of the Cambrian explosion and is revealed by the appearance of numerous new species with complex morphology. Based on phenetic morphological features alone, more than 100 early Cambrian form-species are described. However, because some biological species produced morphologically diverse stages in their life cycle, which may be preserved and thus recognized as separate form-species, the number of acritarch species may be overestimated. Similarly, the number of species of Leiosphaeridia may be exaggerated because of the lack of objective features to distinguish them. In fact, acritarch species reflect the morphological disparity of phytoplankton, displayed by ornamented cysts, internal dormant or reproductive cells, and external vegetative envelopes that may pertain to a single biological species, and various ecological variants of discrete species. The biodiversity curves constructed on the form-species counts should be revised from the point of view of the morphological disparity, which does not strictly correspond to biodiversity. Global records of early Cambrian acritarchs from the Skiagia plexus reveal that they are stratigraphically significant and can be used as biostratigraphic markers. Skiagia ornata and S. ciliosa have a cosmopolitan distribution and the levels of their first appearance datums are proposed to serve as biostratigraphic horizons for interregional correlation. These levels are close to the lower boundary of the undefined Cambrian Stage 3, and within Stage 3, respectively. The acritarch assemblage diagnostic of the Heliosphaeridium dissimilareSkiagia ciliosa Zone of Baltica is recorded worldwide and some species are traced on four of the Cambrian palaeocontinents that include South Australia, South China and Laurentia. This supports the intercontinental correlation of certain Lower Cambrian strata and establishes the time equivalence between the regional trilobite zones to which these strata are attributed. The biostratigraphic correlation of the Lower Cambrian strata, belonging to different faunal provinces, is based for the first time on the same fossil species, which have a cosmopolitan distribution and well-defined first appearance datums, and on the entire diagnostic acritarch assemblages.

THE MIDDLE CAMBRIAN TRILOBITE CYCLOLORENZELLA KOBAYASHI, 1960 AND RELATED GENERA FROM KOREA AND CHINA: MORPHOMETRIC ANALYSIS AND TAXONOMIC REVISION Tae-yoon Parkh\ Zuozhen Han^ Zhiqiang Bai^ & Duck K. Choi^ ^School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Korea (id7@snu.ac.kr; dkchoi@snu.ac.kr) ^College of Geo-Information Science and Technology, Shandong University of Science and Technology, Qingdao, China ^School of Earth and Space Sciences, Peking University, Beijing 100871, China The genus Cyclolorenzella was established by Kobayashi in 1960 based on a single fragmentary cranidium, originally assigned to Lorenzella quadrata Kobayashi 1935, from the Drepanura Zone of the Sesong Formation, Korea. Subsequently it has been widely documented from the upper Middle Cambrian strata (Damesella-Yabeia, Blackwelderia and Drepanura Zones) of North China, but also has been reported less convincingly from Kashmir and England. More than twenty species were once assigned or transferred to Cyclolorenzella. However, a careful scrutiny of the type specimen of Cyclolorenzella quadrata and new collections from the Gushan Formation of Shandong reveals that all the Chinese species referred to Cyclolorenzella, except C. convexa (Resser and Endo in Endo & Resser 1937), are morphologically distinct from the type species. Principal component analysis of the material also shows that they form three distinct clusters. Consequently the species assigned to Cyclolorenzella are subdivided into three informal morphotypes: i.e., convexa-, acalle-, and regularis-typQS. The convexa-tyipQ comprises two species, C. quadrata and C. convexa, and is characterized by a semicircular cranidium with a very distinctive preglabellar boss; a preglabellar boss outlined by shallow complete furrows, which emerge from the anterolateral comers of the glabella, run parallel to each other and then slightly converge forward; and palpebral lobes that are situated at the glabella midlength. The acalletype includes C. acalle, C. acuta, C. ogurai, C. rotundata, C. subcylindrica, and C. tangshanensis, and differs from the convexa-typQ in having a trapezoidal or subpentagonal cranidium with forwardly-divergent incomplete furrows on the preglabellar field and anteriorly-located palpebral lobes. The regularis-ty^Q is represented by C. regularis only and displays a mixed morphology of the convexa- and acalle-ty^QS in having a semicircular cranidium with forwardly-divergent incomplete furrows on the preglabellar field and anteriorly-located palpebral lobes. They occur successively in the Gushan Formation in Shandong: in ascending order, the acalle-iy^Q in the Damesella-Yabeia and Blackwelderia Zones, the regularis-ty^Q in the lower part of the Drepanura Zone, and the convexa-ty^Q in the upper part of the Drepanura Zone. These morphological changes with time presumably represent a phylogenetic lineage which may eventually have given rise to slightly younger Diceratocephalus. This analysis leads us to suggest that the generic concept of Cyclolorenzella should be restricted to the convexa-Xy^Q, with the acalle- and regularis-ty^QS to be assigned to new genera.

A NEW TRILOBITE ASSEMBLAGE FROM THE Pararaia bunyerooensis ZONE (EARLY CAMBRIAN, SOUTH AUSTRALIA) AND ITS BIOSTRATIGRAPHIC SIGNIFICANCE John R. Paterson & Glenn A. Brock

Centre for Ecostratigraphy & Palaeobiology, Department of Earth & Planetary Sciences, Macquarie University, NSW 2109, Australia

The Pararaia bunyerooensis Zone has been the most poorly understood of the Early Cambrian trilobite zones of South Australia. This was largely due to its supposed low diversity, consisting of the eponym and an indeterminate redlichiid, and its limited occurrence in the Flinders Ranges. This zone has only been previously recorded from the Memmema Formation at Bunyeroo Creek, and from the Third Plain Creek Member of the middle Memmema Formation at Wilkawillina Gorge (Jell in Bengtson et al 1990). A recently discovered silicified trilobite fauna from the Memmema Formation at Angorichina in the eastem Flinders Ranges, South Australia, reveals the presence of a new assemblage from the Pararaia bunyerooensis Zone, including the eponymous species, Yorkella aff australis, Eoredlichia sp., Redlichia sp., and new species of Wutingaspis and Yunnanocephalus (Paterson & Brock, in press). Trilobites of the Pararaia bunyerooensis Zone show a strong affinity with those from the Yu'anshan Member of the Heilinpu Formation in Chengjiang and Jinning counties, Yunnan Province, southwest China. The Pararaia bunyerooensis Zone is correlated with the Yunnanocephalus Assemblage subzone (upper Eoredlichia-Wutingaspis Zone) of the Chiungchussuan (= Qiongzhusian) Stage of China. This, in tum, allows correlation with the early Botoman (Bergeroniellus micmacciformis-Erbiella Zone) of Siberia. References BENGTSON S., CONWAY MORRIS S., COOPER B. J., JELL P. A. & RUNNEGAR B. N. 1990. Early Cambrian fossils from South Australia. Memoirs of the Association of Australasian Palaeontologists 9, 1-364. PATERSON J. R. & BROCK G. A., (in press). Early Cambrian trilobites from Angorichina, Flinders Ranges, South Australia, with a new assemblage from the Pararaia bunyerooensis Zone. Journal of Paleontology 81.

POTENTIAL GLOBAL STANDARD STRATOTYPE-SECTIONS (GSSPs) AT LUOYIXI, NW HUNAN AND DUIBIAN, W ZHEJIANG, SOUTH CHINA FOR UNDEFINED CAMBRIAN STAGE 7 AND CAMBRIAN STAGE 9 Peng Shanchi\ Loren E. Babcock^, Lin Huanling\ Zuo Jingxun\ Zhu Xuejian\ Zhou Chaunming\ Yang Xianfeng\ Qi Yueping\ & Li Quan^ ^State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology), Chinese Academy of Sciences, Nanjing 210008, China ^Department of Geological Sciences, The Ohio State University, Columbus, Ohio 43210, USA The first appearances of two cosmopolitan agnostoid trilobites, Lejopyge laevigata and Agnostotes orientalis, are among the most recognizable levels on an intercontinental scale, which can serve to define global Cambrian stages. The first appearance datum (FAD) of Lejopyge laevigata will be used to define the base of so-far-undefined Stage 7, the upper stage of so-far-undefined Series 3 in the newly approved Cambrian chronostratigraphic fi-amework (Babcock et al., 2005), whereas that of Agnostotes orientalis will define the base of the so far undefined Stage 9, the middle stage of the Furongian Series. In searching for Cambrian Global Standard Stratotype Sections and Points (GSSPs) in South China, two well exposed carbonate sections at Luoyixi, near Wangcun, northwestern Hunan and at Duibian, near Jiangshan, western Zhejiang are selected fi-om well documented Cambrian sections of South China for extensive investigation. These two sections bear the lowest occurrences of Lejopyge laevigata and of Agnostotes orientalis respectively. As indicated by the results of recent years, both sections meet the requirements for establishing a GSSP, and are highly qualified to be candidates for GSSPs defining the bases of the Stage 7 and 9. The Luoyixi section, known also as the Wangcun South section, comprises an interval of some 100 m in the Huaoqiao Formation, which embraces the Goniagnostus nathorsti, Lejopyge armata and Lejopyge laevigata zones. The section sits on the south bank of the Youshui River, opposite the Wangcun section, from which the agnostoid and polymerid trilobites have been thoroughly studied in recent years (Peng & Robison 2000; Peng et al. 2004). The L. armata Zone is a newly recognized agnostoid zone in the lower part of the L. laevigata Zone (in a broad sense) as defined by Peng & Robison (2000). The observed FAD of Lejopyge laevigata is at 64.4 m above the base of the measured section which is some 80 m above the base of the Huaqiao Formation. Carbon isotopic studies show that the FAD of Lejopyge laevigata coincides with a medium negative carbon isotopic excursion. The Duibian B section is located some 250 m south of the Duibian section that was studied by Lu & Lin (1989) who reported a single occurrence of Agnostotes orientalis in the upper part of the Huayansi Formation. The Duibian B section, lying on the same flank of a syncline as the Duibian section, comprises an interval of 42 m in the upper part of the Huayansi Formation, which bears the Erixanium rectangularis, Corynexochus plumulaSinoproceratopyge kiangshanensis, Agnostotes orientalis, and Eolotagnostus duibianensis zones. In the Duibian B section Agnostotes orientalis is recorded from five horizons with its lowest occurrence observed at 19.72 m above the base of the measured section, which is some 105 m above the base of the Huayansi Formation. In addition, Irvingella is recorded from four horizons in the Duibian B section. As an important taxon, Irvingella had never been previously recorded from the sections everjrwhere in western Zhejiang. For its intercontinental distribution, Irvingella can serve as a second tool for defining the middle stage of the Furongian. Its finding at Duibian will certainly enhance the scientific value of the Furongian sections of western Zhejiang. At least three Irvingella species are recognized in our collection, among which I angustilimbata makes its first appearance at the same level, as does A. orientalis. Carbon isotopic study shows that the FAD of Agnostotes orientalis occurs near the top of a large positive carbon isotopic excursion (SPICE).

References BABCOCK L. E., PENG SHANCHl, GEYER G. & SHERGOLD J. H. 2005. Changing perspectives on Cambrian chronostratigraphy and progress toward subdivision of the Cambrian System. Geoscience Journal 9, 101-106. PENG SHANCHl & ROBISON R. A. 2000. Agnostoid biostratigraphy across the Middle-Upper Cambrian boundary in China. Paleontological Society Memoir 53, 1-104. PENG SHANCHl, BABCOCK L. E. & LIN HUANLING 2004. Polymerid trilobites from the Cambrian of northwestern Hunan, China. Volume 1, 1-333; volume 2, 1-355, Beijing: Science Press. LU YANHAO & LIN HUANLING 1989. The Cambrian trilobites of western Zhejiang. Palaeontologica Sinica, series B 25(178), 1-287.

ARCHAEOCYATHAN BIOSTRATIGRAPHY AND PALAEOBIOGEOGRAPHY OF THE SOUTHWESTERN MARGIN OF GONDWANA Antonio Perej6n\ Elena Moreno-Eiris\ & Silvia Menendez^ ^Instituto de Geologia Econdmica CSIC-UCM. Facultad de Ciencias Geoldgicas. Universidad Complutense de Madrid. ^ Museo Geominero Instituto Geologico y Minero de Espaha. (aparqueo(a).2eo. ucm. es\ eiris(a),2eo. ucm. es, s. menendez(a)is:me. es)

The Lower Cambrian platforms in the SW Gondwanan margin offer a wide record of archaeocyaths from the Ovetian (Atdabanian) to the Bilbilian (Toyonian). These Cambrian porifera grew on shallow carbonate platforms and they were bioconstmctor elements of the mounds, mainly as components in skeletal mounds or as accessory elements with calcimicrobes in microbial mounds. Before carrying out palaeobiogeographical analyses, the ecological factors that control the distribution of these organisms must be considered, but the presence of some archaeocyathan genera in other palaeogeographic areas allows us to analyse the geographic dispersion potential. The biostratigraphic precision of each genus allows us to determine the source area and migration patterns during the Early Cambrian. The stratigraphic distribution of the genera is related to the chronostratigraphic subdivision of Russian stages, which are perfectly calibrated with the Spanish subdivisions. The geographic distribution of the genera is given taking into account their presence in different areas such as the Siberian Platform, Kolyma, Altay Sayan, Baikal, Mongolia, Tuva and the Far East and Hinggan in the Siberian plate. Morocco, Spain, Sardinia, Montagne Noire and Normandy (France), Germany, central Asia (Urals, Kazakhstan,etc), China, Australia, Antarctica and South Africa are the areas for Gondwana. Pacific and Atlantic North America and Greenland are the areas for Laurentia. The Lower Cambrian in southwestern Gondwana is divided into ten archaeocyathan zones, defined by archaeocyathan genera assemblages, with reference to the trilobite, small shelly fossils and ichnofossil genera that are found in these successions. The established zones are in precise stratigraphic position and correlated with the stages published by Russian authors. The stratigraphic ranges of archaeocyathan genera in different geographic areas of the Lower Cambrian allow us to determine the following properties: a) the cosmopolitan character, b) their area of appearance, c) the main migration ways, d) the type of communication of the different palaeogeographic areas during some intervals in the Lower Cambrian, and e) their biostratigraphic value and their precision. The data have been inserted into an Excel calculus sheet to obtain the graphics on each genus, which allow us precision analysis of the biogeographic and biostratigraphic characteristics.

BIOSTRATIGRAPHIC PROPOSAL BASED ON ARCHAEOCYATHS AND SMALL SHELLY FOSSILS FOR THE SOUTHWESTERN MARGIN OF GONDWANA AND A TENTATIVE CORRELATION Antonio Perej6n\ Elena Moreno-Eiris\ David Fernandez-Remolar^ Diego C. Garcia-Bellido^ & Silvia Menendez^

Înstituto de Geologia Econdmica CSIC-UCM, Facultadde Ciencias Geoldgicas. Universidad Complutense de Madrid. ^Centra de Astrobiologia INTA. ^Museo Geominero. Instituto Geoldgico y Minero de Espaha. {aparqueo(a).2eo. ucm. es; eiris(a),jêo. ucm. es, fernandezrd(a)inta. es, Dieô. GBC&.êo. ucm. es, s. menendez(a)j2me. es) The Lower Cambrian in southwestern Gondwana is divided into ten archaeocyathan zones, defined by generic assemblages with reference to trilobite taxa found in these successions (Perejon 1986), and later addition of small shelly fossil and ichnofossil genera (Perejon 1994, Femandez-Remolar 2001, Linan et al. 2004). The established zones are in precise stratigraphic position and correlated with the Russian stages. The palaeontological assemblages in each archaeocyathan zone of the Iberian Peninsula allow the establishment of correlations between Germany, Normandy, Montagne Noire, Morocco and Sardinia. This proposal completes or modifies those made by other authors (Debrenne et al 1992, Geyer et al. 1995, Linan et al. 1993, Zhuravlev 1995). For the detailed archaeocyath assemblages see Perejon et al. (2005). The precise stratigraphic position is an essential criterion for establishing this tentative correlation. CORDUBIAN: The Lower Cordubian is characterized by the Monomorphichnus lineatus and Phycodes pedum Zone. Phycodes pedum also appears in Avalonia and is considered as an index-fossil for the Precambrian/Cambrian boundary. In the East Galician-Castilian area, besides the ichnofossil assemblage containing these taxa, there are also other fossils such as anabaritids, bigotinids, chancellorids, halkierids, hyolithids and sponges. In the LusitanianAlcudian area, the occurrence of Sabellidites cambriensis may support the correlation with the Watsonella-Sabellidites assemblage from Australia, and the presence of Anabarella may be correlated with the Baltic Platform of Upper Nemakit-Daldynian age. The Upper Cordubian is here characterized by the Cruziana-Rusophycus Zone, with Rusophycus also occurring in the Baltic Platform. OVETIAN: The Lower Ovetian is characterized by archaeocyathan Zones I, II and III. There are several common taxa with Morocco, which allows Zones I and II to be correlated with the Atdabanian. The occurrence of Astropolichnus hispanicus in several Spanish regions may be correlated with Normandy and Sardinia, with most of their localities from the lowermost levels of the Lower Ovetian. In the Sierra de Cordoba several phosphatized molluscs and other shelly remains have been found co-occurring with Zone I archaeocyathan taxa. Hispanoconus cordobaensis sp. nov., Obtusoconus reduncus sp. nov., Latouchella arcuata sp. nov., Helcionella atdabanica, Bestashella tortilis, Archiasterellapentactina, Tannuolina sp., Conotheca mammilata and Actinotheca sp. appear, among other remains, at the bottom of the Lower Oventian deposits near Cordoba (Femandez-Remolar 2001; Gubanov et al 2004). Zone III is correlated with Atdabanian 2, the archaeocyathan genera occur in Morocco, Normandy and Germany. The taxa shared with Morocco are Agastrocyathus, Dictyocyathus, Erismacoscinus, Neoloculicyathus, Nochoroicyathus, Protopharetra, Retecoscinus and Rotundocyathus; taxa shared with Normandy are Nochoroicyahtus, Protopharetra, Sibirecyathus and the trilobite Bigotina bivallata. With Germany the shared genera are Cordobicyathus, Dictyocyathus, Erismacoscinus, Neoloculicyathus, Nochoroicyathus, Protopharetra and Retecoscinus. In Zones IV and V of the Upper Ovetian in Spain, the archaeocyathan record is scarce, with just five genera. However, it is worth noting that this is the earliest occurrence of

Rasetticyathus, equivalent to Atdabanian 3 and 4, but in Sardinia and China it has a Botomian age. The uppermost Ovetian is represented by archaeocyathan Zones VI and VIL The assemblage of Zone VI presents the highest diversity of genera, and the first appearance of Anthomorpha is correlated to early Botomian age in Montagne Noire and Sardinia (Sa Tuvara Member). There is one trilobite species in common with Montagne Noire, Granolenus midi. The assemblage of Zone VII is correlated with Sardinia (Monte Azziedas and Punta Su Pranu Members) and the upper levels of Montagne Noire; the age corresponds to Botomian 2. In Morocco the Botomian 1 and 2 are characterized by the Pollystillicidocyathus/Paranacyathus/Leptosocyathus Zone. MARIANIAN: The assemblages of Zones VIII and IX are characteristic of the Botomian 3 from the West Ossa-Morena area, and are correlated with Sardinia (Santa Barbara and Planu Sartu Formations) and with Morocco {Jebileticoscinus /Porocyathellus Zone). Some shelly taxa, such as the ones forming the Saukiandia-'&XMifQ fauna, found by Richter & Richter (1940), seem to occur in the Upper Marianian (Femandez-Remolar 2001). BILBILIAN: Zone X is characterized by an assemblage of Archaeocyathus, Okulitchicyathus, Polythalamia and Pycnoidocyathus. Archaeocyathus and Pycnoidocyathus are common in Sardinia (San Giovanni Formation), while different species of Archaeocyathus are recorded from Altay Sayan, Australia, China, Laurentia, Sardinia and the Siberian Platform. The age of this unit is equivalent to Toyonian 1 and 2. References DEBRENNE F. & ZHURAVLEV A.YU. 1992. Irregular Archaeocyaths. Editions du CNRS, Paris, 212p. FERNANDEZ-REMOLAR D. C. 2001. Latest Neoproterozoic to Middle Cambrian body fossil record in Spain (exclusive of trilobites and archaeocyaths). Geologiska Foreningens i Stockholm Forhandlingar 123, 73-80. GEYER G., LANDING E. & HELDMAIER W. 1995. Faunas and depositional environments of the Moroccan Atlas region. Beringeria, Special Issue 2, 47-119. GUBANOV A. P., FERNANDEZ REMOLAR D. C. & PEEL J. S. 2004. Early Cambrian molluscs from Sierra de Cordoba (Spain). Geobios 37, 199-215. LINAN E., PEREJON A., GOZALO R., MORENO-EIRIS E. & OLIVEIRA J. T. 2004. The Cambrian System in Iberia. Cuad. Mus. Geominero 3, 1-63. LINAN E., PEREJON A. & SDZUY K. 1993. The Lower-Middle Cambrian stages and stratotypes from the Iberian Peninsula: a revision. Geological Magazine 130, 817-833. PEREJON A. 1986. Bioestratigrafia de los Arqueociatos en Espana. Cuad. Geol Iter, 9 [1984], 213266.

PEREJON A. 1994. Palaeogeographic and biostratigraphic distribution of Archaeocyatha in Spain. Cours. Forsch.-Inst. Senck, 111, 341-354. PEREJON A., MORENO-EIRIS E. & GARCIA-BELLIDO D.C. 2005. Biostratigraphic proposal based on Archaeocyaths for the southwestem margin of Gondwana, and its global correlation, Acta Micropalaeontologica Sinica, 22 (Supplement), 150-151. RICHTER R. & RICHTER E. 1940. Die Saukiandia-StaffQ von Andalusien, eine fremde Fauna in europaisle Ober-Kambrium. Abh. Senckenb. Naturforsch. Ges., 450, 1-88. ZHURAVLEV A. YU. 1995. Preliminary suggestions on the global Early Cambrian zonation. Beringeria, Special Issue!, 147-160.

Dailyatia SCLERITES FROM THE ARROWIE BASIN - UNEXPECTED TAXONOMIC DIVERSITY AND MORPHOLOGICAL COMPLEXITY OF A LOWER CAMBRIAN PROBLEMATICUM. Christian B. Skovsted Centre for Ecostratigraphy & Palaeobiology, Department of Earth & Planetary Sciences, Macquarie University, NSW 2109, Australia Extensive collections of small shelly fossils from numerous localities in the Arrowie Basin (Flinders Ranges) have revealed a previously undocumented faunal diversity and biostratigraphical resolution within the Hawker Group. In particular, well preserved sclerites of various tommotiid taxa are very common. Tommotiid sclerites were formed by basalinternal accretion of phosphate, and multiple sclerites are presumed to have formed a scleritome of unknown size and construction (Landing 1984; Bengtson 1986). The group was common throughout most of the Lower Cambrian, but died out in the Middle Cambrian, and very little is known about its relationships to other metazoan groups, although a relationship to brachiopods have been suggested (Williams & Holmer 2002). Among all tommotiids, the genus Dailyatia Bischoff 1976 appear to have had the most complex scleritome. Laurie (1986) recognized three basic sclerite types (A, B and C), each of which occur in two morphs (Ai, A2, etc.). While the A sclerites are bilaterally symmetrical, both the B and C sclerites are asymmetrical, and occur in left and right handed symmetry pairs. This model thus includes a total of ten different sclerite varieties in one scleritome. A previously undocumented morphological diversity was found among a total of about 1000 Dailyatia sclerites from seven sections through the sediments of the Hawker Group. As many as six different species of Dailyatia (five new) may be represented, but complete sclerite sets are only known for three of these. The Dailyatia species have overlapping geographical and stratigraphical ranges and as many as three species can be found in one sample. However, the unexpected diversity suggests that Dailyatia, and possibly other tommotiid genera, may provide the basis for a regional biostratigraphy. Close examination of Dailyatia has also revealed a number of new morphological features. Muscle scars and paired muscle platforms in different sclerite types of the same scleritome provide the first detailed evidence for the muscle system of tommotiids. More difficult to interpret is the fact that all Dailyatia sclerites appear to have one, occationally two, open perforations at the apex. A sensory function may be the most likely explanation for the perforations in Dailyatia, although no other tommotiids appear to have had perforated apices. References BENGTSON S. 1986. A new Mongolian species of the Lower Cambrian genus Camenella and the problems of scleritome-based taxonomy of the Tommotiidae. Paldontologische Zeitschrift 60, 45-55. BISCHOFF G. C. O. 1976. Dailyatia, a new genus of the Tommotiidae from Cambrian strata of SE. AustraUa (Crustacea, Cirripedia). Senckenbergiana Lethaea 57, 1-33. LANDING E. 1984. Skeleton of lapworthelHds and the supragenetic classification of tommotiids (Early and Middle Cambrian phosphatic problematica). Journal of Paleontology 58, 1380-1398. LAURIE J. R. 1986. Phosphatic fauna of the early Cambrian Todd River Dolomite, Amadeus Basin, central Austraha. Alcheringa 10, 431-454. WILLIAMS A. & HOLMER L. E. 2002. Shell structure and inferred growth, functions and affinities of the sclerites of the problematic Micrina. Palaeontology 45, 845-873.

PREDATORY DRILL HOLES IN Lapworthella fasciculata FROM THE WILKAWILLINA LIMESTONE, WILKAWILLINA GORGE, FLINDERS RANGES, SOUTH AUSTRALIA Mitchell Smith

Centre for Ecostratigraphy & Palaeobiology, Department ofEarth & Planetary Sciences, Macquarie University, NSW 2109, Australia Lapworthellids are problematic small shelly fossils with a widespread distribution in Lower Cambrian successions around the globe. Phosphatic in composition, these tiny coniform fossils are thought by some (e.g. Bengtson et al 1990) to be elements that compose a larger external scleritome of a (probably bilaterian) animal whose nature remains elusive. Earher investigations into lapworthellids have been hampered by the highly variable morphology of sclerite form and a lack of specimens. One study by Conway Morris & Bengtson (1994) has previously documented predatory holes in Lapworthella from Siberia. A new large collection from the Wilkawillina Limestone (Atdabanian) type section at Wilkawillina Gorge in the eastern Flinders Rangers, South Australia has yielded at total of -- 4000 sclerites of Lapworthella fasciculata Conway Morris & Bengtson (in Bengtson et al 1990), with some 50 specimens displaying small circular holes. Preferential drilling occurs between the prominent concentric ridges in an area where the sclerite is considerably thinner, strongly suggesting a predatory origin for the holes. There are two distinct sizes ranges of drill holes, though this may be a function of the different sizes of inter ridge areas along a size gradient for individual sclerites. Holes appear to be randomly located on the sclerite and there is typically only one hole per sclerite. This new evidence has direct implications for understanding the growth and palaeobiology of Lapworthella, suggesting that the internal cavity of each sclerite probably consisted of soft tissue (possibly epithelial) that attracted the attention of potential predators. It seems reasonable to assume that this soft tissue may also have played a role in forming internal septa and possibly the walls of individual sclerites. References CONWAY MORRIS S. & BENGTSON S., 1994. Cambrian Predators: Possible evidence from hoYoholQS. Journal ofPaleontology 1-23. BENGTSON S., CONWAY MORRIS S., COOPER B. J., JELL P. A. & RUNNEGAR B. N., 1990. Early Cambrian fossils from South Australia. Memoirs of the Association of Australasian Palaeontologists 9, 1-364.

REVISED MIDDLE TO UPPER CAMBRIAN TRILOBITE BIOSTRATIGRAPHY OF THE SESONG AND HWAJEOL FORMATIONS, TAEBAEK GROUP, TAEBAEKSAN BASIN, KOREA Jang Won Sohn & Duck K. Choi School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Korea (dkchoi@snu.ac.kr) The Cambrian-Ordovician Taebaek Group is a siliciclastic-carbonate succession representing shallow marine facies of the Taebaeksan Basin in Korea and has been divided into ten lithostratigraphic units: i.e., in ascending order Jangsan/Myeonsan, Myobong, Daegi, Sesong, Hwajeol, Dongjeom, Dumugol, Makgol, Jigunsan, and Duwibong Formations. Over 20 biozones were recognized within the Taebaek Group by Kobayashi (1966), but most of these biozones were not well defined and accordingly have seldom been subsequently relocated. Recent detailed investigations on the Middle to Upper Cambrian Sesong and Hwajeol Formations reveal that the previous trilobite biostratigraphy has to be profoundly revised. Kobayashi (1966) established seven biozones in the Sesong and Hwajeol Formations of the Taebaek Group: in ascending order Stephanocare and Drepanura zones of the Sesong Formation; and Prochuangia, Chuangia, Kaolishania, Dictyites, and Eoorthis zones of the Hwajeol Formation. In this study we are able to locate five biozones from the Sesong and Hwajeol Formations: from oldest to youngest, they are the Drepanura, Kaolishania, Ptychaspis, Quadraticephalus, and Mictosaukia Zones. The Sesong Formation contains the lower two biozones, while the Hwajeol Formation includes the upper three zones. The Middle Cambrian Drepanura Zone is recognized at the lower part of the Sesong Formation and is composed predominantly of damesellid trilobites, such as Cyclolorenzella sp., Drepanura sp., Blackwelderia octaspina Resser & Endo 1937, Blackwelderia sp., Bergeronites sp., and Shantungia sp. The middle part of the Sesong Formation is poorly fossiliferous and so far no biozones have been documented in this interval. The Kaolishania Zone was previously known to occur in the Hwajeol Formation (Kobayashi 1935, 1966), but is herein recovered from the uppermost part of the Sesong Formation. It is recognized by the association of characteristic trilobites, Kaolishania granulosa Sun 1924 and Taishania taianensis Sun 1935. The superjacent Ptychaspis Zone from the lowermost part of the Hwajeol Formation yields Pseudagnostus planulatus (Raymond 1924), Ptychaspis subglobosa Sun 1924, Tsinania canens (Walcott 1905), Tsinania sp., mAHaniwa sp. The succeeding Quadraticephalus Zone comprises a relatively diverse trilobite assemblage composed of twelve species belonging to eight genera: namely, Pseudagnostus planulatus, Pseudagnostus sp., Micragnostus hoiformis Kobayashi 1933, Koldinioidia sp., Sinosaukia angulata (Sun 1924), Sinosaukia sp., Quadraticephalus elongatus Kobayashi 1935, Tsinania canens, Hamashaniapulchera Kobayashi 1942, Hamashania sp. cf. H. busiris (Walcott 1905), ?indHaniwa sp. The uppermost Cambrian Mictosaukia Zone includes Micragnostus sp., Koldinioidia sp., Mictosaukia sp., Calvinella sp., Coreanocephalus sp., Haniwa sosanensis Kobayashi 1933, and Pagodia sp. This refined Middle to Upper Cambrian trilobite biozonation of the Taebaeksan Basin provides a more reliable correlation than known previously and can be traced, zone by zone, into coeval zones of North China, hence supporting a close palaeobiogeographic link between the Taebaeksan Basin and the North China Platform during the Cambrian Period.

References KOBAYASHI T. 1935. The Cambro-Ordovician formations and faunas of South Chosen. Paleontology, Part III, Cambrian faunas of South Chosen with a special study on the Cambrian trilobite genera and families. Journal of the Faculty of Science, Imperial University of Tokyo, Section II4,49344. KOBAYASHI T. 1966. The Cambro-Ordovician formations and faunas of South Korea, Part X, Stratigraphy of the Chosen Group in Korea and South Manchuria and its relation to the CambroOrdovician formations and faunas of other areas, Section A, The Chosen Group of South Korea. Journal of the Faculty of Science, University of Tokyo, Section II16, 1-84.

THE CHENGJIANG FAUNA: A UNIQUE WINDOW INTO THE CAMBRIAN EXPLOSION Sun Weiguo State Key Laboratory of Paleobiology and Stratigraphy, Nanjing Museum of Palaeontology, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, P.R.China, (wgsun@nigpas.ac.cn) Through the extremely long history of the evolution of life, the most spectacular and enigmatic phenomenon is the explosive radiation of life in very early Cambrian time, commonly called the "Cambrian explosion". In the geological record everywhere in the world, it seems that the Cambrian faunas almost suddenly appeared. In his monumental masterpiece "The Origin of Species", Charles Darwin in 1859 noticed such an unfathomable phenomenon and tried to explain the sudden appearance of abundant and diversified invertebrates "in the lowest known fossiliferous strata" by referring it to "the imperfection of the geological record". Although he considered that the case at his time must remain inexphcable, he recognized that it might be used as a valid argument against his views on the evolution of life. The Early Cambrian Chengjiang fauna from East Yunnan in southwestern China is one of the most exciting discoveries of the last century. This discovery has made the Cambrian explosion appear to be much more sudden than ever before suspected. Many thousands of specimens have been collected from mudstones of the Eoredlichia Zone, the second oldest trilobite zone, with an age of about 530 Ma. Both shelled and soft-bodied animals are exceptionally well preserved. The soft-bodied preservation is so remarkable that naturally very delicate structures, such as muscles, gut, antennae, appendages and even eyes, are preserved almost intact. The superb preservation has allowed a great variety of animals to be documented, including many strange forms found for the first time in the fossil record, e.g. Microdictyon and Yunnanozoon. From the type locality at Maotianshan (Maotian Hill) and several other localities in the eastern mountainous district of Chengjiang County (National Geopark of the Chengjiang Fauna), about 120 species have been described from more than 10 extant phyla and include sponges, coelenterates, priapulids, lobopods, brachiopods, molluscs, arthropods and chordates plus several problematic taxa, e. g. eldoniids and vetulicolids, that represent extinct major groups and can not be assigned to any known phyla. The Chengiang fauna reveals the true composition and general appearance of marine communities from 530 million years ago, extends the fossil records of most living animal phyla back to the beginning of the Cambrian, and provides extremely valuable evidence for deciphering the mystery of the "Cambrian explosion" in the early evolutionary history of life. The discovery of the Chengjiang fauna attested to the existence of the "Cambrian explosion", the most significant radiation event in the evolutionary history of life. The ftindamental framework of animal diversity, i.e. the phylogenetic evolution at the level of phyla, was already established in the "Cambrian explosion", while all extant animal phyla were derived through evolution from some of those that existed in the Early Cambrian. However, the discovery of the Chengjiang fauna does not indicate that all extant animal phyla could have generated in a geological instant at the start of the Cambrian. Palaeontological and molecular-biological data have consistently demonstrated that the phylogenetic relationship between different phyla is varying in distance. As so many highly diversified metazoan groups occurred in the same Chengjiang fauna, simple or complex, primitive or advanced, from sponges to chordates, this phenomenon strongly supports the concept that long periods of biological evolution must have occurred before the earhest Cambrian time.

THE IDENTITY OF THE Mongolitubulus ANIMAL AND DOCUMENTATION OF SMALL SHELLY FOSSILS FROM THE UPPER MERNMERNA FORMATION AT DONKEY BORE SYNCLINE, CENTRAL FLINDERS RANGES, SOUTH AUSTRALIA Timothy P. Topper Centre for Ecostratigraphy & Palaeobiology, Department of Earth & Planetary Sciences, Macquarie University, NSW 2109, Australia The Donkey Bore Syncline, located in the central Flinders Ranges, contains a suite of deeper water carbonates and siliciclastics representing sediments of the Hawker Group in the Arrowie Basin. Recent sampling through the transgressive upper Memmema Formation has revealed the presence of a well preserved, diverse phosphatic small shelly fossil assemblage including species of Dailyatia, Lapworthella, the enigmatic bradoriid taxon Mongolitubulus and various other bradoriid species. The bradoriid species are represented by exceptionally preserved complete carapaces with additional characteristic ornamented spines and fragments. Although Mongolitubulus is a common constituent of Early Cambrian small shelly fossil assemblages, the morphology and affinity of the organism which secreted the spines has been controversial. Dzik (2003), for instance, suggested Mongolitubulus should be restored as defensive spines of a lobopod-like organism. Current views favour a defensive functional morphology affiliated with bradoriid arthropods (Skovsted & Peel 2001, Skovsted 2005, Skovsted et al in press). The discovery of a bradoriid specimen exhibiting a single mature spine of Mongolitubulus attached to the central portion of its carapace provides definitive evidence of a bradoriid affinity for this widespread SSF taxon. The faunal assemblage in the upper Memmema Formation at Donkey Bore Syncline facilitates correlation with successions to the south, in particular the Bunkers, Chace and Elder Ranges, within the Arrowie Basin and neighbouring depocentres in the Stansbury and Officer Basins. References DZIK J. 2003. Early Cambrian lobopodian sclerites and associated fossils from Kazakhstan. Palaeontology 46, 93-112 SKOVSTED C. B. & PEEL J. S. 2001. The problematic fossil Mongolitubulus from the Lower Cambrian of Greenland. Bulletin of the Geological Society of Denmark 48, 135-147 SKOVSTED C. B. 2005. A carapace of the bradoriid arthropod Mongolitubulus from the Early Cambrian of Greenland. Geologiska Foreningens i Stockholm Fdrhandlingar 127, 217-220. SKOVSTED C. B., BROCK G. A. & PATERSON J. R. in press. Bivalved arthropods from the Lower Cambrian Memmema Formation, Arrowie Basin, South Australia and their implications for identification of Cambrian small shelly fossils. Memoir of the Association of Australasian Palaeontologists 32.

THE LOWER-MIDDLE CAMBRIAN FAUNA FROM THE CANTABRIAN MOUNTAINS (NORTH-WESTERN SPAIN): PALAEOENVIRONMENTAL AND PALAEOBIOGEOGRAPHICAL CONSIDERATIONS Thomas Wotte Freiberg University of Mining and Technology, Institute of Geology, D-09599 Freiberg, Germany (Thomas. wotte@geo. tufreiberg. de) The Cantabrian zone is situated in the NW of the Iberian Peninsula. The most complete Cambrian succession (Figure 1) is found only in its western section; this reflects a continuous drowning of the mixed carbonate-siliciclastic Cantabrian ramp environment. The base of this succession is represented by the siliciclastic ?Neoproterozoic-Lower Cambrian Herreria Formation. It rests unconformably on the Precambrian basement, and passes continuously into the carbonate-rich Lower - Middle Cambrian Lancara Formation. The Lancara Formation is divided into a lower and an upper member that are in turn overlain by the siliciclastic Middle Cambrian - Ordovician Oville Formation. Significant are the diachronic boundaries between the different formations and members, characterised by a southwest-directed movement into stratigraphic younger positions. For over three years the carbonates of the Lancara Formation have been the focus of our research with special emphasis given to its microfauna and its lithologic and stratigraphic characteristics. Whereas the fossil content of the siliciclastic portions is rather poor, the Lancara Formation (especially the upper member) contains a highly diverse fauna of trilobites, echinoderms, brachiopods, chancelloriids and sponges, as well as molluscs and phosphatic small shelly fossils. The investigation and documentation of about 60 outcrops of the Lancara Formation, more than 400 thin sections, and dissolved rock samples allowed the reconstruction of the palaeoenvironment of the Lancara Formation, as well as yielding a fundamental increase in the knowledge of stratigraphic ranges, taxonomy, and paleobiology of the faunal elements of the Lower - Middle Cambrian interval for this part of the European Gondwana shelf Thus, new taxa of lingulid, acrotretid, paterinid, obolellid and kutorginid brachiopods, and helcionellid molluscs could be verified. Hyolithelminths, hyolithes and cambroclaves are documented for the first time from this area. With the first detection of Ctenocephalus cf coussesensis (Thoral 1946) from the uppermost part of the upper member of the Lancara Formation, the first time detection of this species in the Cantabrien zone, but overall its stratigraphic distribution till the ?Lower Caesaraugustan could be evidenced. Until now this form was only known from the southern Montagne Noire, representing an Upper Caesaraugustan to Upper Languedocian age. This talk presents the faunal content of the Lower - Middle Lancara Formation; special stratigraphic positions, and facies characteristics will be pointed out. Further, the palaeoecological, palaeobiogeographical, and biostratigraphical relevance of this fauna is discussed.

Iberian Nomenclature

Classification of the Cambrian of the Cantabrian zone

p. (A.) mi ire mens is

.s m

g u

s o

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Haniatoleniis (H.) ihericus V) Protolenus (Hripeolemis)

Realaspis Serrocliscus

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Andahisiana

'^Stfvrmaeva " ') ^'Stre- KL nuella " VIII-IX Granolernis Lemda•ci1-H della .AZ > Bigotina I-VII

Serrania

Cla\ stone Sandstone Limestone Dolostone Cae. Caesaraugustan AZ Archaeocvathan zones

Si:

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B. Badulesia zone (H.) (Hamatolemis) PcirdaiUuintcf zone P. (A. Paradoxides (A cadoparadoxides) zone S. Solenopkiiropsis

Figure 1. Stratigraphy and biostratigraphy of the Cambrian of the Cantabrian zone.

THE FIRST SERIES OF THE CAMBRIAN OF SOUTH CHINA: SUBDIVISION AND CORRELATION Zhu Maoyan\ Zhang Junming\ Yang Aihua^ Li Guoxiang^ & Yang Xinglian^ ^LPS, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing, 210008, China ^Department of Earth Sciences, Nanjing University, Nanjing 210093, China ^Institute of Resource and Environment, Guizhou University, Guiyang 550003, China According to the newly defined four series subdivision of the Cambrian, the traditional lower Cambrian has to be subdivided into two series. If the FAD of trilobites is adapted to define the boundary between the First and Second series, the First series should be strata between the base of the Cambrian and the FAD of trilobites. However, application of the FAD of Trichophycus pedum for defining the base of the Cambrian in successions outside of Newfoundland has met major problems, and the FAD of trilobites may not be a synchronous horizon in different palaeogeographic regions. Consequently, the First Series of the Cambrian remains a poorly defined stratigraphic interval resulting in numbers of conflicting applications amongst geologists. In this regard, before establishing global criteria for subdivision and correlation of the First Series of the Cambrian, regional subdivision and correlations should be determined. The succession of the First Series of the Cambrian from shallow to deep water facies of the Yangtze Platform outcrops widely in South China. Based on our recent investigations on more than 50 sections, some major results on litho-, bio- and chemostratigraphy are presented. Lithostratigraphically, the succession of the First Series of the Cambrian is characterised by rocks rich in phosphorus and consists of two parts. The lower part is composed of carbonates, phosphorites and cherts, generally with a sharp contact at the base in shallow water facies. The thickness of the lower part varies from less than 1 m up to 200 m. The upper part comprises siliciclastic rocks with a sharp contact at the base as well. The upper part of the First Series in South China generally represents a condensed interval (thickness ranging from <1 m to 80 m) with abundant phosphatic nodules at the base. Biostratigraphically, four assemblages of small shelly fossils (SSF) can be recognized; these are well represented in eastern Yunnan. The composite carbonate carbon isotopic profile, based on 14 sections from the shallow water facies, demonstrates that the First Series starts with a negative C isotopic excursion. The C isotope data gradually increases in the lower part and reaches a major positive excursion at the top of the lower part of the succession. This is followed by a sharp negative excursion at the base of the upper part of the succession; this is succeeded by a gradual increase in the C isotope data, but it remains negative up to the top of the succession. Integrated correlation indicates the succession of the First Series of the Cambrian in South China is generally incomplete in most areas of the shallow water facies and very condensed in deep water facies. The thickest successions are developed in the basins of the platform interior, located in eastern and northeastern Yunnan (Zhujiaqing and Shiyantou Formations), Emei in central Sichuan (Maidiping Formation and lower member of the Jiulaodong Formation), Ningqiang of southern Shaanxi (Kuanchuanpu Formation and lower member of the Guojiaba Formation), and south of the Yangtze Gorges (Yanjiahe Formation and lower member of the Shuijintuo Formation). The bottom and top boundaries of the First Series of the Cambrian of South China are the FADs of Trichophycus pedum and Parabadiella huoi respectively from the Meishucun section, Jinning, E Yunnan. Integrated chronostratigraphic correlations of the First Series of the Cambrian of South China with those of Siberia, Mongolia, Iran, India, Morocco and

Newfoundland demonstrate that the First Series can be subdivided into three globally recognized stages as follows: (1) If there is no revision of the GSSP at the base of the Cambrian, the First Stage is defined by the FAD of Trichophycus pedum (ca. 538 Ma). According to the Chinese sections, the first stage overlays an interval with a negative C isotope excursion with the occurrence of some distinct small (<15|im) acanthomorphic acritarchs at the base (ca. 542 Ma) and the first appearance of SSF at the top (ca. 540 Ma). (2) The Second Series is characterized by a distinct positive C isotope excursion. It is suggested that its base be defined by the first occurrence of the globally distributed Watsonella crosbyi near the base of the isotope excursion (ca. 530 Ma). (3) The Third Series is marked by a negative C isotope excursion at the base (ca. 525Ma) with new appearances of a number of shelly metazoan taxa, such as archaeocyatha, chancelloriids and other groups of SSF.

ON Shergoldia ZHANG & JELL, 1987 (TRILOBITE) AND TSINANIIDAE Zhu Xuejian^ & Peng Shanchi^ ^ Department of Earth Sciences, Nanjing University, Nanjing 210093, China ^State Key Laboratory on Palaeontology and Stratigraphy; Nanjing Institute of Geology and Palaeontology, the Chinese Academy of Sciences, Nanjing 210008, China Some Furongian articulated specimens of Shergoldia laevigata sp. nov., found in a section at Guole, Jingxi County, southwestern Guangxi Province, China, reveal both its dorsal and ventral characters. The cephalic ventral view shows a rostral plate, which is triangular in outline and defined by outward curved connective sutures laterally, and a hypostoma lying in natant condition. The general dorsal morphology of Shergoldia laevigata sp. nov., including eight thoracic segments, is reminiscent of asaphids. However, Shergoldia laevigata sp. nov. is distinguished by lacking median suture, instead, by developing a rostral plate, which is not known in any asaphids, and by the natant rather than conterminant hypostoma condition as known in asaphids. According to Fortey & Chatterton (1988), the median suture may have arisen by reduction and eventual loss of the rostral plate, and conterminant hypostomal condition could be attained from natant hypostomal condition by different mechanisms, such as backward extension of doublure or loss of preglabellar field (Fortey 1990). As showed by the new material oi Shergoldia, it could be referable that the genus may stand in the same but prior to the lineage of asaphids and give arise to some trilobites of this group by the possible loss of rostral plate and a possible backward extension of doublure or anterior shift of preglabellar furrow, because the connective sutures in Shergoldia laevigata sp. nov. is tend to move adaxially to form median suture and eliminate the rostral plate. In the meantime, attachment of hypostoma against the inner margin of doublure could be attained by reducing the short distance between the inner margin of doublure and anterior margin. Both Tsinania and Shergoldia are commonly classified in the same Family: the Tsinaniidae Kobayashi, 1935 (Zhang & Jell, 1987; Shergold, 1991; Jell & Adrain, 2003). Before the discovery of complete exoskeleton and ventral character, the assignment of Tsinaniidae is only based on dorsal features of disarticulated specimens, and as a result, the family has been referred to different superfamilies by different authors, e.g. Ptychoparioidea (Shaw, 1951; Kobayashi, 1962), Asaphoidea (Hupe, 1955; Lochman in Moore ed., 1959; Chemysheva, 1960; Lu et al 1965), Leiostegioidea (Shergold, 1975, 1991) and Illaenoidea (Fortey, 1990; Fortey in Whittington et al, 1997). Based on the speculation mentioned above, it is reasonable to place Tsinaniidae in the Asaphoidea.

Figure 1. Shergoldia laevigata sp. nov. A, nearly complete internal mould of exoskeleton, x 0.8; B, same specimen as A with the anterior left preglabellar region removed off to uncover rostral plate and doublure, xl.05; C, partial enlargement of the anterior part of B, showing the

rostral plate; arrows show the posterior margin of hypostoma and preglabella furrow respectively, x2.1; D, incomplete internal mould of exoskeleton, xl.05; E, latex cast from D, showing the hypostoma and rostral plate; arrow shows the posterior margin of librigenal doublure, xl.05; F, partial enlargement of E, showing the rostral plate, x2.1.

SOUTH AUSTRALIA 2006 -LIST OF PARTICIPANTS Per Ahlberg, Department of Geology, GeoBiosphere Science Centre, Lund University, Solvegatan 12, SE-223 62 Lund, Sweden (per.ahlberg@geoLlu.se) Elinor Alexander, Primary Industry and Resources SA, GPO Box 1671, Adelaide, South Australia 5000, Australia (Alexander.Elinor@saugov.sa.gov.au) Loren Babcock, Department of Geological Sciences, Ohio State University, Columbus, Ohio 43210, USA (lbabcock@columbus.rr.com) Glenn Brock, Department of Earth and Planetary Sciences, Macquarie University, New South Wales 2109, Australia (gbrock@els.mq.edu.au) Duck K. Choi, School of Earth and Environmental Sciences, Seoul National University, Seoul 151-747, Korea (dkchoi@snu.ac.kr) Barry Cooper, Primary Industry and Resources SA, GPO Box 1671, Adelaide, South Australia 5000, Australia (Cooper.Barry@saugov.sa.gov.au) Terry Fletcher, Bowmont Cottage, East Links Road, Dunbar, East Lothian, Scotland, EH42 ILT (teepeebow@hotmail.com) Margaret Fuller, South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia (fullersm@kem.com.au) Diego Garcia-Bellido, U.E.I de Paleontologia, Instituto de Geologia Economica (CSICUCM), Facultad de Ciencias Geologicas, Jose Antonio Novais 2, 28040-Madrid, Spain (Diego.GBC@geo.ucm.es) Colin Gatehouse, 4 Frontignac Avenue, Wattle Park, South Australia 5066, Australia (gatehouse@olis.net.au) Jim Gehling, South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia (gehling.iim@saugov.sa.gov.au) Gerd Geyer, Institut fur Palaontologie, Pleicherwall 1, 97070 Wurzburg, Germany (gerd.geyer@mail.uni-wuerzburg.de) Stew and Mary Hollingsworth, Institute for Cambrian Studies, 729 25 Road, Grand Junction, CO 81505, USA (stewholl@aol.com) Jim and Adrienne Jago, School of Natural and Built Environments, University of South Australia, Mawson Lakes, South Australia, 5095, Australia (jim.jago@unisa.edu.au) Imseong Kang, Laboratory of Paleontology, School of Earth and Environmental Sciences, NS80, College of Natural Sciences, Seoul National University, Seoul 151-747, Korea (imseongkang@gmail.com) Pierre Kruse, Northern Territory Geological Survey, GPO Box 3000, Darwin, Northern Territory 0801, Austraha. (Pierre.Kruse@nt.gov.au) Ed Landing, New York State Museum, Madison Acenue, Albany, New York 12230, USA (elanding@maiLnysed.gov) Seung-bae Lee, Laboratory of Paleontology, School of Earth and Environmental Sciences, NS80, College of Natural Sciences, Seoul National University, Seoul 151-747, Korea (sblee77@snu.ac.kr) Li Guoxiang, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, China (gxU@nigpas.ac.cn) Jih-Pai Lin, The Ohio State University, Department of Geological Sciences, 125 South Oval Mall, Columbus, Ohio 43210, USA (jplin@hotmail.cm) Luo Kunli, Institute of Geographical Sciences and Natural Resource Research, Chinese Academy of Sciences, 1 lA Datun Road, Anwai, Beijing 100101, People's RepubHc of China (luokl@igsnrr.ac.cn) Linda McCollum, Geology Department, 130 Science Building, Eastern Washington University, Cheney, WA 99004, USA (lmccollum@mail.ewu.edu) Brian McGowran, School of Earth and Environmental Sciences, DP313, University of Adelaide, South Australia 5005 (brian.mcgowran@adelaide.edu.au) Malgorzata Moczydlowska-Vidal, Department of Earth Sciences-Palaeobiology, Uppsala University, Norbyvagen 22, SE-752 36 Uppsala, Sweden (malgo.vidal@pal.uu.se)

Sang June Moon, Laboratory of Paleontology, School of Earth and Environmental Sciences, NS80, College of Natural Sciences, Seoul National University, Seoul 151-747, Korea (threesee@hanmail.net) Elena Moreno-Eiris, Departamento de Paleontologia, Instituto de Geologia Economica (CSIC-UCM), Facultad de Ciencias Geologicas, Jose Antonio Novais 2, 28040-Madrid, Spain (eiris@geo.ucm.es) Tae-yoon Parkh, Laboratory of Paleontology, School of Earth and Environmental Sciences, NS80, College of Natural Sciences, Seoul National University, Seoul 151-747, Korea (id7@snu.ac.kr) John Paterson, Department of Earth and Planetary Sciences, Macquarie University, New South Wales 2109, Australia (agnostoid@hotmail.com) Peng Jin, School of Resource and Environment Engineering, Guizhou University (Caijiaguan Campus), Guiyang, 550003 People's RepubUc of China (gzpengjin@sina.com) Peng Shanchi, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, China (scpeng@nigpas.ac.cn) Antonio Perejon, U.E.I de Paleontologia, Instituto de Geologia Economica (CSIC-UCM), Facultad de Ciencias Geologicas, Jose Antonio Novais 2, 28040-Madrid, Spain (aparqueo@geo.ucm.es) James St John, 1179 University Drive, Ohio State University at Newark, Newark, Ohio 43055, USA (stjohn.2@osu.edu) Christian Skovsted, Department of Earth and Planetary Sciences, Macquarie University, New South Wales 2109, Australia (cskovsted@els.mq.edu.au) Mitchell Smith, Centre for Ecostratigraphy & Paleobiology, Department of Earth and Planetary Sciences, Macquarie University, New South Wales 2109, Australia Jang Won Sohn, Laboratory of Paleontology, School of Earth and Environmental Sciences, NS80, College of Natural Sciences, Seoul National University, Seoul 151-747, Korea (odive@hanmail.net) Sun Weiguo, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, China (wgsun@nigpas.ac.cn) Sun Xiaowen, 32A Lincoln Street, Kensington Gardens, South Australia 5068, Australia (xiao w e n s @y ahoo. com. au) Timothy Topper, Centre for Ecostratigraphy & Paleobiology, Department of Earth and Planetary Sciences, Macquarie University, New South Wales 2109, Australia Thomas Wotte, Institute of Geology, Freiberg University of Mining and Technology, Bemhard-von-Cotta Street 2, D-09599 Freiberg, Germany (thomas.wotte@geo.tu-freiberg.de) Zang Wenlong, Primary Industry and Resources SA, GPO Box 1671, Adelaide, South Austraha 5000, Australia (zang.wen-long@saugov.sa.gov.au) Zhao Yuanlong, School of Resource and Environment Engineering, Guizhou University (Caijiaguan Campus), Guiyang, 550003 People's RepubUc of China (gzpengjin@sina.com) Zhu Maoyan, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, China (myzhu@nigpas.ac.cn)