Oct. 24-26, 2009, Yingjie Overseas Exchange Center, Peking University, Beijing, China中文版

Deep Root of the Modern Animal Diversity

Jun-Yuan Chen

Nanjing Institute of Geology and Paleontology, CAS, China

Abstract

Beautifully preserved organisms from the Lower Cambrian Maotianshan Shale in central Yunnan, southern China, document the sudden appearance of diverse metazoan body plans at phylum or subphylum levels, which were either short-lived or have continued to the present day. These 530 million year old fossil representatives of living animal groups provide us with unique insight into the foundations of living animal groups at their evolutionary roots. Among these diverse animal groups, many including ctenophores, priapulids, sipunculans, arrow worms, tunicates, linguloids, are conservative, changing very little since the Early Cambrian. Others, especially Panarthropoda (superphylum), however, evolved rapidly, with origination of novel body plans representing different evolutionary stages one after another in a very short geological period of Early Cambrian time. These nested body plans portray a novel big picture of pararthropod evolution as a progression of step-wise changes both in the head and the appendages. The evolution of the pararthropods displays how the head/trunk boundary progressively shifted to the posterior, and how the simple annulated soft uniramous appendages progressively changed into stalked eyes in the first head appendages, into whip-like sensorial and grasping organs in the second appendage, and into jointed and biramous bipartite limbs in the post-antennal appendages. The two-segmented head in the original arthropod body plan contributes new understanding to the meaning of the otd/ems-Hox boundary and why this boundary was buried within the head, and it also challenges the deeply-rooted hypothesis of the tripartite-brain. Haikouella is one of most remarkable fossils representing the origin body plan of Cristozoa, or “crest animals” (procraniates+craniates). The anatomy of Early Cambrian crest animals, including Haikouella and Yunnanozoon, contributes to novel understanding and discussion for the origins of the vertebrate brain, neural crest cells, branchial system, and vertebrae. Lophophore-bearing organisms include a group of sessile, stalked organisms known as Phlogites (=Chenungkongella) and a group of medusaform organisms (including Eldonia and Rotadiscus), which have been interpreted as tunicate and problematic, respectively. Restudy of their body plans reveal that they are likely the fossil representatives of extinct basal deuterostomes, in a close affinity with echinoderms. Vetulicolians remain one of the Cambrian’s biggest controversies, being recently interpreted as a basal deuterostome group. Restudy of their body plan suggests that they were a distinct pararthropod group related to arthropods.

Jun-Yuan Chen

Nanjing Institute of Geology and Paleontology, CAS, China

Biography

He is the author of several books and monographs, and publishes over hundred of research papers, numerously in Science, Nature, and other international high classified journals with a brief list of current oublications (see attached appendix).

He has received senior research fellowship from several institutions of different countries and region (including: Univ. of Rochester, NY, States in 1991-1982; Royal Museum of Ontario, Toronto, Canada in 1982-1983; Univ. of Stockholm during 1989-1990; and Tsing-Hua Univ., Taiwan, China in 1998), and owned the high praise as one of “National Distinguishing Scientist of Middle to Young age” from by China National Council of Science and Technology in 1987. He also received the Gordon and Betty Moore Distinguished Scholar fellowship from Caltech in 2008.

He wins the National Prize for Natural Sciences (First Grade) at 2003; being the awardee for several prizes from Chinese Academy of Sciences (Special Grade at 1997, First Grade at 1991, and Second Grade at 1987); receiving Qiu-Shi Prize for Scientific achievement from Hongkong Qiu-Shi Foundation at 1997, and Prize for Natural Sciences (First Grade) from Jiangsu Province at 2003. He also wins the medal from Nanjing as “One of ten achievements in Science & Technology” at 1997.  In 2007, he received two prizes: Li Sgi-Guan prize and He Liang-Li Liang prize. He received an honour as one of the ten most outstanding researchers in Jiansu Province since 1949y in 2009.

Appendix： Brief list of current publications
Chen jun-yuan, Bottjer D.J., Gang L, Hadfield§, M.G., Gao F., Cameron A.R. , Zhang C.-Y., Xian D-C., Tafforeau P, Liao X, and Yin Z-Y, 2009. Complex embryos displaying bilaterian characters from Precambrian Duoshantou phosphate deposits, Weng’an, Guizhou, China. PNAS.( will be issued on 19, October).
Chen Jun-yuan, 2009. The sudden appearance of diverse animal body plans during the Cambrian Explosion. International Journal of Developmental Biology.53, 733-751.
Chen J-Y, Bottjer D-J et al. 2009.  Synchrotron X-ray tomography of Neoproterozoic metazoan microfossils: Phylogenetic diversity and evolutionary implications. Precambrian Research。173,191-200.
Chen Jun-Yuan. Early Crest Animals and the insight they provide into the origin of craniates. Genesis４6 (2008)：623-639。
Chen Jun-Yuan, Schopf J. William，Bottjer David J., Chen-Y Zhang, Kudryavtsev Anatoliy B.，Tripathi Abhishek B., Wang Xiu-Qiang, Yang Yong-Hua, Gao Xiang, and Yang Ying. Raman Spectra of a Lower Cambrian ctenophore embryo from SW Shaanxi, China. PNAS. 104(15)(2007): 6289-6292。
Chen. Junyuan, 2004. The Dawn of Animal World. Jiangsu Publishing House of Science and Technology, Nanjing (2004) (Chinese).p.1-306, 546 figs in color.
Chen, Jun-yuan, David J. Bottjer, Eric H. Davidson, Stephen Q. Dornbos, Xiang Gao, Yong-Hua Yang, Chia-Wei Li, Gang Li, Xiu-qiang Wang, Ding-chang Xian, Hung-Jen Wu, Yeu-Kuang Hwu, Paul Tafforeau, 2006. Phosphatized Polar Lobe-Forming Embryos from the Precambrian of Southwest China. Science 312: 1644-1646.
Chen Jun-yuan, D.J. Bottjer, P. Oliveri, S.Q. Dornbos, Gao Feng, S. Ruffins,`, Li Chiawei, & E.H. Davidson. Small Bilaterian Fossils from 40 to 55 Million Years Before the Cambrian. Science 305（2004）: 218-222.
Chen Jun-yuan, Oliveri, P., Davidson E. & D.J. Bottjer. Response to Comment on “Small Bilaterian Fossils from 40 to 55 Million Years Before the Cambrian”. Science 306（2004）: 1291b.
Chen Jun-yuan and Huang Di-ying.　A possible Lower Cambrian Chaetognath (Arrow Worm).　Science 298（2002）: 197。
Chen Jun-yuan, Huang Di-yong, & Li Chi-wei.　An Early Cambrian craniate-like chordate.　Nature 402（1999）: 518－522.
Li Chia-wei, Chen Jun-yuan & Huai, T-E,　Precambrian sponges with cellular structure.　Science 279（1998）: 879－882。
Chen Jun-yuan, Dzick, J., Edgecombe, G. D., Ramsköld, L., Zhou Gui-qing.　The earliest chordate from Early Cambrian, Yunnan, China.　Nature 377（1995）: 720－722。
Chen Jun-yuan, Edgecombe, G. D., Ramsköld, L. & Zhou Gui-qing.　Head Segmentation in Early Cambrian Fuxianhuia: Implications for Arthropod evolution.　Science 268（1995）: 1339－1343。
Mallatt, J. and Chen Jun-yuan,. Fossil Sister Group of Craniates: Predicted and Found. Journal of Morphology 258（2003）: 1-31.
Chen Jun-yuan, Ramsköld, L. & Zhou Gui-qing.　Evidence for monophyly and Arthropod affinity of Cambrian giant predatos.　Science 264（1994）: 1304－1308。
Chen Jun-yuan, Huang Di-ying, Peng Qing-qing, Chi Hui-mei, Wang Xui-qing &Feng Man. The first tunicate from Early Cambrian of south China. PNAS 100(14)(2003):8314-8318.
Chen Jun-yuan, Olivert, P., Li Chi-Wei., Zhou Gui-Qing,　 Feng Gao, Hagadorn, J.W., Peterson, K.J. & Davidson, E.H. Precambrian animal diversity: Putative phosphatized embryos from the Doushantuo Formation of China.　PNAS 97(9)（2000）: 4457－4462.
Chen, Jun-yuan, Di-ying Huang & D.J. Bottjer, 2005: Vetustovermis and its possible affinities. Proc. R. Soc. B. 272:2003-2007.
Huang Di-ying, Chen Jun-yuan, Vannier J. &  Saiz Salinas, J.I., Early Cambriansipunculan worms from southwest China, Proc. R. Lond. B271（2004）: 1671-1676 .
Chen Jun-yuan, Oliveri, P., Gao Feng, Dornbos, S.Q., Li, C. W., Bottjer, D.J. & Davidson, E. H,　Precambrian Animal Life: Probable Developmental and Adult Cnidarian Forms from Southwest China.　Developmental Biology 248(1)（2002）：182-196。
Mallatt J., Chen Jun-yuan, Holland, N.D. Comment on “A New Species of Yunnanozoan with Implications for Dcuterostome Evolution. Science 300（2003）: 1372.
Holland, N.D. and Chen Jun-yuan. Origin and early evolution of the vertebrates: new insights from advances in molecular biology, anatomy, and palaeontology.　Bio Essays 23 (2) （2001）: 142-151。
Chen Jun-yuan, Jean Vannier & Huang Di-Ying.　The origin of crustanceans: new evidence form the Early Cambrian of China.　Proceedings of Royal Society, London B 268（2001）: 1-7.
Ramsköld,L., Junyuan Chen, Edgecombe, G.D. and Guiqing Zhou.  Cindarella and the arachnate clade Xandarellida (Arthropoda, Early Cambrian) from China. Transaction of the Royal Society of Edinburgh: Earth Science 88:19-38, 1997.
Huang Di-Ying, Jun-Yuan Chen, Vannier Jean and Saiz Salinas J.I.. Early Cambrian sipunculan worms from southwest China. Proc. R.Soc.Lond.B (2004) 271:1671-1676 .
Chen Jun-yuan, Zhou Guiqing and Lars Ramsköld. A new Early Cambrian onychophoran-like animal Paucipodia gen, nov., from the Chengjiang fauna, China. Transactions of the Royal society of Edinburgh: Earth Science 85: 275-282,1995.
Chen Jun-yuan, Zhou Gui-qing & Ramsköld, L. A new Early Cambrian onychophoran -like animal Paucipodia gen. nov., from the Chengjiang fauna, China. Transaction of the Royal Society of Erdinburgh,Earth Sciences 85（1995）: 275－282.
Vannier, J. & Chen, Jun-yuan. Early Cambrian food chain: new evidence from fossil aggregates in the Maotianshan Shale Biota, SW China. Palaios 20（2005）: 3-26.
Waloszeck, D., Chen Jun-yuan, Maas, A. and Wang Xiu-qiang. Early Cambrian Arthropods – New Insights into Arthropod Head and Structural Evolution. Arthropod Systematic and Development 34(2)（2005）：189-205 .
Dornbos S.Q., Bottjer D.J., and Chen Jun-yuan. Paleoecology of benthic metazoans in the Early Cambrian Maotianshan biota and the Middle Cambrian Burgess Shale biota: evidence for the Cambrian substeate revolution. Palaios. （2005）.
Dornbos, S.Q., Bottjer D.J., & Chen. Jun-yuan, 2005. Paleoecology of benthic metazoans in the Early Cambrian Maotianshan Shale biota and the Middle Cambrian Burgess Shale biota: evidence for the Cambrian subtrate revolution. Palaios 220: 47-67.
Dornbos, S. Q., Bottjer,D.J., Chen Jun-yuan, Oliveri, P., 2005. Precambrian animallife: Taphonomy of hosphatized metazoan embryos from southwest China. Lethaia 38: 101-109.
Chen Jun-yuan, D. Waloszek, and A. Maas. A new ‘great-appendage’ arthropod from the Lower Cambrian of China and homology of chelicerate chelicerae and raptorial antero-ventral appendages. Lethaia 37（2004）: 3-20.
Dornbos S.Q., Bottjer D.J., and Chen Jun-yuan. Evidence for seafloor microbial mats and associated metazoan lifestyles in Lower Cambrian phosphorites of Southwest China. Lethaia 37（2004）: 127-137.
Huang Di-ying, Vannier, J. & Chen Jun-yuan. Anatomy and lifestyles of Early Cambrian priapulid worms exemplified by Corynetis and Anningvermis from the Maotianshan Shale (SW China). Lethaia 37（2004）: 21-33.
Huang Di-ying, Vannier, J. & Chen Jun-yuan. Recent Priapulidae and their Early Cambrian ancestors: comparisons and evolutionary significance. Geobios 37（2004）: 217-228.
Zhu, Mao-yan, Zhao Yuan-long and Chen Jun-yuan,　Revision of the Cambrian medusiform animals Stellostomites eumorphus Sun et Hou and Pararotadiscus guizhouensis (Zhao et Zhu) from South China.　Geobios 35（2002）: 165-185。
Vannier, J. & Chen Jun-yuan,　Digestive system and feeding mode in Cambrian naraoiid arthropods.　Lethaia 35（2002）: 107-120。
Vannier. J. & Chen Jun-yuan.　The Early Cambrian colonization of pelagic niches exemplified by Isoxys (Arthropoda).　Lethaia 33（2000）: 295-331。
Chen J.Y., G.Q. Zhou G.Q., Zhu M.Y. & Yeh K.Y., 1997. The Chengjiang Biota: a unique window of the Cambrian Explosion. Taichung, National Museum of Natural Science Press, 1997. (in Chinese ).(p.1-222, with 292 figs).
Ramsköld, L.& Chen Jun-yuan,　Preservational folds simulating tergite junctions in tegopeltid and naraoiids arthropods.　Lethaia 29（1996）: 15-20。
Chen Jun-yuan, Zhu Mao-yan, & Zhou Gui-qing.　The early Cambrian medusiform metazoan Eldonia from Chengjiang Lagerstätte.　Acta Palaeontologica Polonica 40(3)（1995）: 213－244, 17figs。
Chen Jun-yuan & Lindström, M. Cephalopod septal strength indices (SSI) and depositional depth of Swedish Orthoceratite limestone.　Geologica et Palaeonologica 25 （1991）: 5－18, 13 textfigs, 11 Tabs。
Chen Jun-yuan, Edgecombe, G. D., Ramsköld, L.　Morphological & ecological disparity in Naraoiids (arthropoda) from the Early Cambrian Chengjiang fauna, China.　Records of the Australia Museum 47（1997）: 1－24。
Chen Jun-yuan, Braun A., Waloszek D., Peng Qingqing and Maas. A. Lower Cambrian yolk-pyramiod embryos from southern Shaanxi, China. Progress in Natural Science 14(2) （2004）: 167-172.
Chen Jun-yuan & Zhou Gui-qing, 1997. Biology of the Chengjiang Fauna.　Bulletin of National Museum of Natural Science 10: 11-106。
Ramsköld, L. & Chen Jun-yuan,　Cambrian Lobopodians: Morphology and Phylogeny.　In: Edgecombe (ed.), Arthropod Fossils and Phylogeny.（1998）107-150, Columbia Press。
Chen Jun-yuan, Cheng Yehnian & Van Iten H. (eds),　The Cambrian explosion and the fossil records.　Taichung, National Museum of Natural Science Press,（1997） 1-318。
Chen Jun-yuan & Teichert C. Cambrian Cephalopoda of China.　Palaeontographica, Abt. A., Bd. 181, p. 1－102, 19pls。(1983)。
Chen Junyuan & Chi Huimei, 2005. Precambrian Phosphatized Embryos and Larvae from Doushantuo Formation, Guizhou (S.W. China) and Their Affinity. Chinese Science Bulletin 50(19): 2193-2200.