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Phosphatized animal embryos from the Neoproterozoic Doushantuo Formation at Weng'an, Guizhou, South China
Published online by Cambridge University Press: 20 May 2016
Abstract
Phosphorites of the uppermost Neoproterozoic Doushantuo Formation (ca. 570 ± 20 Ma) exposed at Weng'an, South China, contain globular microfossils characterized by distinctively sculpted outer coverings and precise patterns of cell division. Forms assigned to the genera Megasphaera and Parapandorina were originally interpreted as problematica and volvocacean green algae, respectively, but newly discovered populations support their reinterpretation as the eggs and embryos of early animals. The fossils' large size (about half a millimeter in diameter), persistent enveloping membrane, precise cleavage pattern, and inferred physiology are fundamentally different from those of volvocaceans or other algae, but are expected features of animal embryos preserved in early stages of cleavage. In this light, Megasphaera is interpreted as an egg enveloped within its egg case, and Parapandorina represents equally and totally cleaving stereoblastulas. Despite their exquisite preservation, the phylogenetic placement of Megasphaera and Parapandorina cannot be resolved with confidence, due largely to the absence of recognizable adult morphologies to which they might be linked. Individual characters of Megasphaera and Parapandorina can be found in eggs and embryos of extant sponges, cnidarians, and bilaterians.
Three other distinctive globular forms, Megaclonophycus onustus, Caveasphaera costata n. gen. and sp., and Spiralicellula? bulbifera? occur in the same deposit. Interpretations of these fossils are more problematic, although they may also be animal embryos.
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References
Anderson, D. T.
1973. Embryology and Phylogeny in Annelids and Arthropods (International Series of Monographs in Pure and Applied Biology, Vol. 50). Pergamon Press, Oxford. 495 p.Google Scholar
Awramik, S. M., McMenamin, D. S., Yin, C., Zhao, Z., Ding, Q., and Zhang, S.
1985. Prokaryotic and eukaryotic microfossils from a Proterozoic/Phanerozoic transition in China. Nature, 315:655–658.CrossRefGoogle Scholar
Ayala, F. J., Rzhetsky, A., and Ayala, F. J.
1998. Origin of the metazoan phyla: Molecular clocks confirm paleontological estimates. Proceedings of the National Academy of Sciences, USA, 95:606–611.CrossRefGoogle ScholarPubMed
Belk, D., Mura, G., and Weeks, S. C.
1998. Untangling confusion between Eubranchipus vernalis and Eubranchipus neglectus (Branchiopoda: Anostraca). Journal of Crustacean Biology, 18:147–152.CrossRefGoogle Scholar
Benayahu, Y.
1989. Reproductive cycle and developmental processes during embryogenesis of Clavularia hamra (Cnidaria, Octocorallia). Acta Zoologica (Stockholm), 70:29–36.CrossRefGoogle Scholar
Bengtson, S.
1976. The structure of some Middle Cambrian conodonts, and the early evolution of conodont structure and function. Lethaia, 9:185–206.CrossRefGoogle Scholar
Bengtson, S., Conway Morris, S., Cooper, B. J., Jell, P. A., and Runnegar, B. N.
1990. Early Cambrian Fossils from South Australia. Memoir 9 of the Association of Australian Palaeontologists. Association of Australian Palaeontologists, Brisbane. 364 p.Google Scholar
Bengtson, S., and Yue, Z.
1992. Predatorial borings in late Precambrian mineralized exoskeletons. Science, 257:367–369.CrossRefGoogle ScholarPubMed
Bengtson, S., and Yue, Z.
1997. Fossilized metazoan embryos from the earliest Cambrian. Science, 277:1645–1648.CrossRefGoogle Scholar
Benus, A. P.
1988. Sedimentological context of a deep-water Ediacaran fauna (Mistaken Point Formation, Avalon Zone, eastern Newfoundland), p. 8–9. In
Landing, E., Narbonne, G. M. and Myrow, P. (ed.), Trace Fossils, Small Shelly Fossils and the Precambrian-Cambrian Boundary. Bulletin of the New York State Museum.Google Scholar
Berger, S., and Kaever, M. J.
1992. Dasycladales: An Illustrated Monograph of a Fascinating Algal Order. Georg Thieme Verlag, Stuttgart, 247 p.Google Scholar
Bi, Z., Wang, X., Zhu, H., Wang, Z., and Ding, F.
1988. The Sinian of southern Anhui. Professional Papers of Stratigraphy and Palaeontology, 27–60.Google Scholar
Boaden, P. J. S.
1989. Meiofauna and the origins of the Metazoa. Zoological Journal of the Linnean Society, 96:217–228.CrossRefGoogle Scholar
Bold, H. C., and Wynne, M. J.
1985. Introduction to the Algae. Prentice-Hall, Englewood Cliffs, New Jersey, 720 p.Google Scholar
Boury-Esnault, N., Efremova, S., Bezac, C., and Vacelet, J.
1999. Reproduction of a hexactinellid? sponge: first description of gastrulation by cellular delamination in the Porifera. Invertebrate Reproduction and Development, 35:187–201.CrossRefGoogle Scholar
Brasier, M.
1990. Phosphogenic events and skeletal preservation across the Precambrian-Cambrian boundary interval, p. 289–303. In
Notholt, A. J. G. and Jarvis, I. (ed.), International Geological Correlation Program, 11th and final international field workshop and symposium; Project 156, Phosphorites. Geological Society of London, London. United Kingdom.Google Scholar
Brasier, M., and McIlroy, D.
1998.
Neonereites uniserialis from c. 600 Ma year old rocks in western Scotland and the emergence of animals. Journal of the Geological Society, London. 155:5–12.CrossRefGoogle Scholar
Brookfield, M. E.
1994. Problems in applying preservation, facies and sequence models to Sinian (Neoproterozoic) glacial sequences in Australia and Asia. Precambrian Research, 70:113–143.CrossRefGoogle Scholar
Bureau of Geology and Mineral Resources of Guizhou Province. 1987. Regional Geology of Guizhou Province. Chinese Ministry of Geology and Mineral Resources, Geological Memoirs, series 1, number 7. Geological Publishing House, Beijing. 698 p.Google Scholar
Bureau of Geology and Mineral Resources of Shaanxi Province. 1989. Regional Geology of Shaanxi Province. Chinese Ministry of Geology and Mineral Resources, Geological Memoirs, series 1, number 13. Geological Publishing House, Beijing. 1–698 p.Google Scholar
Chen, J., Li, C.-W., Chien, P., Z. G.-Q., , and Gao, F.
1999. Weng'an Biota—A light casting on the Precambrian world, p. 43–46. In
Chen, J., Chien, P., Bottjer, D., Li, G.-X. and Gao, F. (ed.), Symposium on the Origin of Animal Body Plans and Their Fossil Record. Kunming.Google Scholar
Chen, M., and Liu, K.
1986. The geological significance of newly discovered microfossils from the upper Sinian (Doushantuo age) phosphorites. Scientia Geologica Sinica, 1:46–53.Google Scholar
Chen, M., and Xiao, Z.
1991. Discovery of the macrofossils in the Upper Sinian Doushantuo Formation at Miaohe, eastern Yangtze Gorges. Scientia Geologica Sinica, No. 4:317–324.Google Scholar
Chen, M., and Xiao, Z.
1992. Macrofossil biota from upper Doushantuo Formation in eastern Yangtze Gorges, China. Acta Palaeontologica Sinica, 31(5):513–529Google Scholar
Chen, M., Lu, G., and Xiao, Z.
1994a. Preliminary study on the algal macrofossils—Lantian Flora from the Lantian Formation of Upper Sinian in southern Anhui. Bulletin Institute of Geology, Academia Sinica, No. 7:252–267.Google Scholar
Chen, M., Xiao, Z., and Yuan, X.
1994b. A new assemblage of megafossils—Miaohe biota from Upper Sinian Doushantuo Formation, Yangtze Gorges. Acta Palaeontologica Sinica, 33(4):391–403Google Scholar
Chen, X., Rowley, D. B., Rong, J.-Y., Zhang, J., Zhang, Y.-D., and Zhan, R.-B.
1997. Late Precambrian through Early Paleozoic stratigraphic and tectonic evolution of the Nanling region, Hunan Province, South China. International Geology Review, 39:469–478.Google Scholar
Child, C. M.
1900. The early development of Arenicola and Sternapsis
. Arch. Entw. Mech. Org., 9:587–723.Google Scholar
Compston, W., Williams, I. S., Kirschvink, J. L., Zhang, Z., and Ma, G.
1992. Zircon U-Pb ages for the Early Cambrian time-scale. Journal of the Geological Society, London, 149:171–184.CrossRefGoogle Scholar
Conway Morris, S. and Chen, M.
1992. Carinachitiids, hexangulaconulariids, and Punctatus: Problematic metazoans from the Early Cambrian of South China. Journal of Paleontology, 66(3):384–406CrossRefGoogle Scholar
Conway Morris, S., and Peel, J.
1995. Articulated halkieriids from the Lower Cambrian of North Greenland and their role in early protostome evolution. Philosophical Transactions of the Royal Society of London B Biological Sciences, 347:305–358.Google Scholar
Dahan, M., and Benayahu, Y.
1998. Embryogenesis, planulae longevity, and competence in the octocoral Dendronephthya hemiprichi
. Invertebrate Biology, 117:271–280.CrossRefGoogle Scholar
Davidson, E. H., Peterson, K. J., and Cameron, R. A.
1995. Origin of bilaterian body plans: Evolution of developmental regulatory mechanisms. Science, 270:1319–1325.CrossRefGoogle ScholarPubMed
Ding, L., Zhang, L., Li, Y., and Dong, J.
1992. The Study of the Late Sinian—Early Cambrian Biotas from the Northern Margin of the Yangtze Platform. Scientific and Technical Documents Publishing House, Beijing, 135 p.Google Scholar
Ding, L., Li, Y., Hu, X., Xiao, Y., Su, C., and Huang, J.
1996. Sinian Miaohe Biota. Geological Publishing House, Beijing. 221 p.Google Scholar
Duncan, I. J., Briggs, D. E. G., and Archer, M.
1998. Three-dimensionally mineralized insects and millipedes from the Tertiary of Riversleigh, Queensland, Australia. Palaeontology, 41:835–851.Google Scholar
Fortey, R. A., Briggs, D. E. G., and Wills, M. A.
1996. The Cambrian evolutionary “explosion”: Decoupling cladogenesis from morphological disparity. Biological Journal of the Linnean Society, 57:13–33.Google Scholar
Fortey, R. A., Briggs, D. E. G., and Wills, M. A.
1997. The Cambrian evolutionary ‘explosion’ recalibrated. BioEssays, 19:429–434.CrossRefGoogle Scholar
Freeman, G.
1983. The role of egg organization in the generation of cleavage patterns, p. 171–196. In
Jeffery, W. R. and Raff, R. A. (ed.), Time, Space, and Pattern in Embryonic Development, MBL Lectures in Biology, vol. II. Alan R. Liss, Inc., New York, NY.Google Scholar
Fritsch, E E.
1965. The Structure and Reproduction of the Algae, vol. 1. Cambridge University Press, Cambridge, 791 p.Google Scholar
Gilbert, S. F., and Raunio, A. M.
1997. Embryology: Constructing the Organism. Sinauer Associates, Sunderland, MA. 1–537 p.Google Scholar
Glenn, C. R., Follmi, K. B., Riggs, S. R., Baturin, G. N., Grimm, K. A., Trappe, J., Abed, A. M., Galli-Olivier, C., Garrison, R. E., Ilyin, A. V., Jehl, C., Rohrlich, V., Sadaqah, R. M. Y., Schidlowski, M., Sheldon, R. E. et al. 1994. Phosphorus and phosphorites: Sedimentology and environments of formation. Eclogae geologicae Helvetiae, 87:747–788.Google Scholar
Grey, K.
1998. Ediacaran Palynology of Australia. PhD Thesis, Macquarie University, Sydney, Australia.Google Scholar
Grotzinger, J. P., Watters, W., and Knoll, A. H. In press. Calcified metazoans in thrombolite-stromatolite reefs of the terminal Proterozoic Nama Group, Namibia. Paleobiology.Google Scholar
Grotzinger, J. P., Bowring, S. A., Saylor, B. Z., and Kaufman, A. J.
1995. Biostratigraphic and geochronologic constraints on early animal evolution. Science, 270:598–604.CrossRefGoogle Scholar
Haeckel, E.
1874. The gastrea theory, the phylogenetic classification of the animal kingdom and the homology of the germ-lamellae. Quarterly Journal of Microscopical Science, 14:142–165.Google Scholar
Hofmann, H. J., Narbonne, G. M., and Aitken, J. D.
1990. Ediacaran remains from intertillite beds in northwestern Canada. Geology, 18:1199–1202.2.3.CO;2>CrossRefGoogle Scholar
Hoffman, P. F.
1991. Did the breakout of Laurentia turn Gondwanaland inside-out?
Science, 252:1409–1412.CrossRefGoogle ScholarPubMed
Iyengar, M. O. P., and Desikachary, T. V.
1981. Volvocales. Indian Council of Agricultural Research, New Delhi, 532 p.Google Scholar
Jägersten, G.
1972. The Evolution of Metazoan Life Cycle. Academic Press, London, 282 p.Google Scholar
Jahn, B.-M.
1997. Discussion on Sm-Nd isotopic age of Precambrian-Cambrian boundary in China. Geological Magazine, 134:571–572Google Scholar
Jenkins, R. J. F., McKirdy, D. M., Foster, C. B., O'Leary, T., and Pell, S. D.
1992. The record and stratigraphic implications of organic-walled microfossils from the Ediacaran (terminal Proterozoic) of South Australia. Geological Magazine, 129:401–410.CrossRefGoogle Scholar
Jura, C., and Krzysztofowicz, A.
1982. Scanning electron microscopy of Tetrodontophora bielanensis (Waga) (Collembola) embryogenesis: Fertilized egg to 64-blastomere stage. Acta Biologica Academiae Scientiarum hungaricae, 33:39–48.Google Scholar
Kasahara, S., Uye, S., and Onbe, T. 1974. Calanoid copepod eggs in sea-bottom muds. Marine Biology, 26:161–171.CrossRefGoogle Scholar
Kato, K.
1968. Platyhelminthes, p. 125–143. In
Kume, M. and Dan, K. (ed.), Invertebrate Embryology. NOLIT, Belgrade.Google Scholar
Knoll, A. H.
1992. Microfossils in metasedimentary cherts of the Scotia Group, Prins Karls Forland, western Svalbard. Palaeontology, 35:751–774.Google Scholar
Knoll, A. H., and Walter, M. R.
1992. Latest Proterozoic stratigraphy and Earth history. Nature, 356:673–678.CrossRefGoogle ScholarPubMed
Knoll, A. H., and Xiao, S.
1999. On the age of the Doushantuo Formation. Acta Micropalaeontologica Sinica, 16:225–236.Google Scholar
Koga, F.
1968. On the pelagic eggs of Copepoda. Journal of the Oceanographical Society of Japan, 24:16–20.CrossRefGoogle Scholar
Kohring, R.
1997. Calcareous dinoflagellate cysts from the Blue Clay Formation (Serravallian, Late Miocene) of the Maltese Islands. Neues Jahrbuch fur Geologie und Palaeontologie Monatsheft, 151–164.Google Scholar
Kolosova, S. P.
1991. Pozdnedokembriyskie shipovatie mikrofossilii vostoka Sibirskoy platformi [Late Precambrian acanthomorphic acritarchs from the eastern Siberian Platform]. Algologiya [Algologia], 1:53–59.Google Scholar
Kouchinsky, A., Bengtson, S., and Gershwin, L.
1999. Cnidarianlike embryos associated with the first shelly fossils in Siberia. Geology, 27:609–612.2.3.CO;2>CrossRefGoogle Scholar
Lambert, I. B., Walter, M. R., Zang, W., Lu, S., and Ma, G.
1987. paleoenvironment and carbon isotope stratigraphy of Upper Proterozoic carbonates of the Yangtze Platform. Nature, 325:140–142.CrossRefGoogle Scholar
Lee, J. S.
1924. Geology of the Gorge district of the Yangtze from Ichang to Tzehui, with special reference to the development of the Gorges. Bulletin Geological Society of China, 3:351–391.CrossRefGoogle Scholar
Li, C.-W., Chen, J.-Y., and Hua, T.-E.
1998. Precambrian sponges with cellular structures. Science, 279:879–882.CrossRefGoogle ScholarPubMed
Li, Y.
1986. Regional review: China, p. 42–62. In
Cook, P. J. and Shergold, J. H. (ed.), Proterozoic and Cambrian phosphorites. Cambridge University Press, Cambridge, United Kingdom.Google Scholar
Li, X.-H.
1999. U-Pb zircon ages of granites from the southern margin of the Yangtze Block: timing of Neoproterozoic Jinning Orogeny in SE China and implications for Rodinia assembly. Precambrian Research, 97:43–57.CrossRefGoogle Scholar
Li, Z. X., Zhang, L., and Powell, C. M.
1995. South China in Rodinia: Part of the missing link between Australia-East Antarctica and Laurentia?
Geology, 23:407–410.2.3.CO;2>CrossRefGoogle Scholar
Li, Z. X., Zhang, L., and Powell, C. M.
1996. Positions of the East Asian cratons in the Neoproterozoic supercontinent Rodinia. Australia Journal of Earth Sciences, 43:593–604.CrossRefGoogle Scholar
Madhupratap, M., Nehring, S., and Lenz, J.
1996. Resting eggs of zooplankton (Copepoda and Cladocera) from the Kiel Bay and adjacent waters (southwestern Baltic). Marine Biology, 125:77–87.CrossRefGoogle Scholar
Martill, D. M., and Wilby, P. R.
1994. Lithified prokaryotes associated with fossil soft tissues from the Santana Formation (Cretaceous) of Brazil. Kaupia, Darmstaedter Beitraeger zur Naturgeschichte, 4:71–77.Google Scholar
Martin, V.
1997. Cnidarians, the Jellyfish and Hydras, p. 57–86. In
Gilbert, S. F. and Raunio, A. M. (ed.), Embryology: Constructing the Organism. Sinauer Associates, Sunderland, MA.Google Scholar
Masters, B. A., and Scott, R. W.
1978. Microstructure, affinities and systematics of Cretaceous calcispheres. Micropaleontology, 24:210–221.CrossRefGoogle Scholar
McCaffrey, M. A., Moldowan, J. M., Lipton, P. A., Summons, R. E., Peters, K. E., Jeganathan, A., and Watt, D. S.
1994. Palaeoenvironmental implications of novel C30 steranes in Precambrian to Cenozoic age petroleum and bitumen. Geochimica et Cosmochimica Acta, 58:529–532.CrossRefGoogle Scholar
Metcalfe, I.
1996. Gondwanaland dispersion, Asia accretion and evolution of eastern Tethys. Australian Journal of Earth Sciences, 43:605–623.CrossRefGoogle Scholar
Moczydłowska, M., Vidal, G., and Rudavskaya, V. A.
1993. Neoproterozoic (Vendian) phytoplankton from the Siberian Platform, Yakutia. Palaeontology, 36:495–521.Google Scholar
Müller, K. J.
1985. Exceptional preservation in calcareous nodules, p. 67–73. In
Whittington, H. B. and Conway Morris, S. (ed.), Extraordinary Fossil Biotas: Their Ecological and Evolutionary Significance. The Royal Society, London.Google Scholar
Müller, K. J., and Walossek, D.
1986. Arthropod larvae from the Upper Cambrian of Sweden. Transaction of the Royal Society of Edinburgh: Earth Sciences, 77:159–179.Google Scholar
Nielsen, C.
1995. Animal Evolution: Interrelationships of the Living Phyla. Oxford University Press, Oxford. 467 p.Google Scholar
Nielsen, C., and Nørrevang, A.
1985. The trochaea theory: An example of life cycle phylogeny, p. 28–41. In
Conway Morris, S., George, J. D., Gibson, R. and Platt, H. M. (ed.), The Origins and Relationships of Lower Invertebrates. The Systematics Association, special volume No. 28. Clarendon Press, Oxford.Google Scholar
Pyatiletov, V. G., and Rudavskaya, V. V.
1990. Acritarchs of the Yudoma complex, p. 179–188. In
Sokolov, B. S. and Iwanowski, A. B. (ed.), The Vendian System, volume 1, Paleontology. Springer-Verlag, Berlin.Google Scholar
Qian, Y.
1977. Hyolitha and some problematica from the Lower Cambrian Meishucun Stage in central and southwestern China. Acta Palaeontologica Sinica, 16:255–275.Google Scholar
Qian, Y., and Bengtson, S.
1989. Palaeontology and biostratigraphy of the Early Cambrian Meishucunian Stage in Yunnan Province, South China. Fossils and Strata, 24:1–156.Google Scholar
Qian, Y., Chen, M., and Chen, Y.
1979. Hyolithids and other small shelly fossils from the Lower Cambrian Huangshandong Formation in the eastern part of the Yangtze Gorge. Acta Palaeontologica Sinica, 18(3):207–232Google Scholar
Qin, S., Zhu, S., Xie, Z., Chen, Y., and Wang, Y.
1984. The Upper Precambrian in Guizhou, p. 37–76. In
Wang, Y., Yin, G., Zheng, S., Qin, S., Zhu, S., Chen, Y., Luo, Q., Zhu, S., Wang, F. and Qian, Y. (ed.), The Upper Precambrian and Sinain-Cambrian Boundary in Guizhou. The People's Publishing House of Guizhou, Guiyang.Google Scholar
Rehánek, J., and Mišík, M.
1991. New Upper Cretaceous cyst Pithonella siniformis n. sp. (Calciodinellaceae) from eastern Algeria. Geologica Carpathica, 42:111–116.Google Scholar
Rieger, R. M.
1994. The biphasic life cycle: A central theme of metazoan evolution. American Zoologist, 34:484–491.CrossRefGoogle Scholar
Runnegar, B.
1982. Molecular-clock date for the origin of the animal phyla. Lethaia, 15:199–205.CrossRefGoogle Scholar
Runnegar, B.
1990. Cyanobacteria, p. 20–24. In
Bengtson, S., Conway Morris, S., Cooper, B. J., Jell, P. A. and Runnegar, B. N. (ed.), Early Cambrian Fossils from South Australia. Memoir 9 of the Association of Australian Palaeontologists. Association of Australian Palaeontologists, Brisbane.Google Scholar
Saylor, B. Z., Kaufman, A. J., and Grotzinger, J. P.
1998. A composite reference section for terminal Proterozoic strata of southern Namibia. Journal of Sedimentary Research, Section B: Stratigraphy and Global Studies, 66:1223–1235.CrossRefGoogle Scholar
Smith, R. J.
1999. Possible fossil ostracod (Crustacea) eggs from the Cretaceous of Brazil. Journal of Micropalaeontology, 18:81–87.CrossRefGoogle Scholar
Spjeldnaes, N.
1963. A new fossil (Papillomembrana sp.) from the Upper Precambrian of Norway. Nature, 200:63–64.CrossRefGoogle Scholar
Steiner, M.
1994. Die neoproterozoischen Megaalgen Sudchinas. Berliner geowissenschaftliche Abhandlungen (E), 15:1–146.Google Scholar
Steiner, M., Mehl, D., Reitner, J., and Erdtmann, B.-D.
1993. Oldest entirely preserved sponges and other fossils from the Lowermost Cambrian and a new facies reconstruction of the Yangtze Platform (China). Berliner geowissenschaftliche Abhandlungen (E), 9:293–329.Google Scholar
Stephens, N. P. and CArroll, A. R.
1999. Salinity stratification in the Permian Phosphoria sea; a proposed paleoceanographic model. Geology, 27:899–902.2.3.CO;2>CrossRefGoogle Scholar
Sun, W.
1986. Late Precambrian pennatulids (sea pens) from the eastern Yangtze Gorge, China: Paracharnia gen. nov. Precambrian Research, 31:361–375.Google Scholar
Thiéry, A., Brtek, J., and Gasc, C.
1995. Cyst morphology of European branchiopods (Crustacea: Anostraca, Notostraca, Spinicaudata, Laevicaudata). Bulletin du Museum National d'Historie Naturelle (4), 17:107–140.Google Scholar
Thompson, M. D., Davidek, K. L., and Bowring, S. A.
1996. New U-Pb zircon age constraint of Neoproterozoic Varanger glaciation from Squantum “tillite”, Quincy, Massachusetts. Abstracts with Programs, Geological Society of America Annual Meeting, 28:493.Google Scholar
Tiwari, M., and Knoll, A. H.
1994. Large acanthomorphic acritarchs from the Infrakrol Formation of the Lesser Himalaya and their stratigraphic significance. Journal of Himalayan Geology, 5:193–201.Google Scholar
Uchida, T., and Yamada, M.
1968. Coelenterata, p. 86–124. In
Kume, M. and Dan, K. (ed.), Invertebrate Embryology. NOLIT, Belgrade.Google Scholar
Valentine, J. W.
1997. Cleavage patterns and the topology of the metazoan tree of life. Proceedings of the National Academy of Sciences, USA, 94:8001–8005.CrossRefGoogle ScholarPubMed
van den Hoek, C., Mann, D. G., and Jahns, H. M.
1995. Algae: An Introduction to Phycology. Cambridge University Press, Cambridge, 623 p.Google Scholar
van Waveren, I. M.
1992. Morphology of probable planktonic crustacean eggs from the Holocene of the Banda Sea, Indonesia, p. 89–120. In
Head, M. J. and Wrenn, J. H. (ed.), Neogene and Quaternary dinoflagellate cysts and acritarchs. Publishers Press, Salt Lake City, UT, United States.Google Scholar
van Waveren, I. M., and Marcus, N. H.
1993. Morphology of Recent copepod egg envelopes from Turkey Point, Gulf of Mexico, and their implications for acritarch affinity, p. 111–124. In
Molyneux, S. G. and Dorning, K. J. (ed.), Contributions to acritarch and chitinozoan research. Palaeontological Association, London, United Kingdom.Google Scholar
Vidal, G.
1990. Giant acanthomorph acritarchs from the upper Proterozoic in southern Norway. Palaeontology, 33:287–298.Google Scholar
Vhtasalo, M.
1992. Calanoid resting eggs in the Baltic Sea: implications for the population dynamics of Acartia bifilosa (Copepoda). Marine Biology, 114:397–405.CrossRefGoogle Scholar
Villain, J. M.
1977. Les Calcisphaerulidae, Architectures, calcification de la paroi et phylogenese [The Calcisphaerulidae; ultrastructure, wall calcification and phylogeny]. Palaeontographica. Abteilung A: Palaeozoologie-Stratigraphie, 159:139–177.Google Scholar
Walter, M. R., Elphinstone, R., and Heys, G. R.
1989. Proterozoic and Early Cambrian trace fossils from the Amadeus and Georgina Basins, central Australia. Alcheringa, 13:209–256.CrossRefGoogle Scholar
Wang, D. Y.-C., Kumar, S., and Hedges, S. B.
1999. Divergence time estimates for the early history of animal phyla and the origin of plants, animals and fungi. Proceedings of the Royal Society, Biological Sciences, 266:163–171.CrossRefGoogle ScholarPubMed
Wang, Z., Yang, J., and Sun, W.
1996. Carbon isotope record of Sinian seawater in Yangtze Platform. Geological Journal of Universities, 2(1):112–120.Google Scholar
Wilby, P. R., and Briggs, D. E. G.
1997. Taxonomic trends in the resolution of detail preserved in fossil phosphatized soft tissues. Geobios, Memoire special No. 20:493–502.CrossRefGoogle Scholar
Wilson, E. B.
1892. The cell lineage of Nereis
. Journal of Morphology, 6:361–455.CrossRefGoogle Scholar
Wray, A. G., Levinton, J. S. and Shapiro, L. H.
1996. Molecular evidence for deep Precambrian divergences among metazoan phyla. Science, 274:568–573.CrossRefGoogle Scholar
Xiao, S., and Knoll, A. H.
1999a. Embryos or algae? A reply. Acta Micropalaeontologica Sinica, 16:313–323.Google Scholar
Xiao, S., and Knoll, A. H.
1999b. Fossil preservation in the Neoproterozoic Doushantuo phosphorite Lagerstatte, South China. Lethaia, 32:219–240.CrossRefGoogle Scholar
Xiao, S., Knoll, A. H., and Yuan, X.
1998. Morphological reconstruction of Miaohephyton bifurcatum, a possible brown alga from the Doushantuo Formation (Neoproterozoic), South China, and its implications for stramenopile evolution. Journal of Paleontology, 72:1072–1086.CrossRefGoogle Scholar
Xiao, S., Zhang, Y., and Knoll, A. H.
1998. Three-dimensional preservation of algae and animal embryos in a Neoproterozoic phosphorite. Nature, 391:553–558.CrossRefGoogle Scholar
Xiao, S., Knoll, A. H., Zhang, L., and Hua, H.
1999. The discovery of Wengania globosa in Doushantuo phosphorites in Chadian, Shaanxi Province. Acta Micropalaeontologica Sinica, 16:259–266.Google Scholar
Xing, Y., Ding, Q., Luo, H., He, T., and Wang, Y.
1984. The Sinian-Cambrian Boundary of China. Bulletin of the Institute of Geology, Chinese Academy of Geological Sciences, 7:1–262 p.Google Scholar
Xue, Y., Zhou, C., and Tang, T.
1999. “Animal embryos”, a misinterpretation of Neoproterozoic microfossils. Acta Micropalaeontologica Sinica, 16:1–4.Google Scholar
Xue, Y., Tang, T., Yu, C., and Zhou, C.
1995. Large Spheroidal Chlorophyta fossils from the Doushantuo Formation phosphoric sequence (late Sinian), central Guizhou, South China. Acta Palaeontologica Sinica, 34(6):688–706Google Scholar
Ye, L., Chen, Q., Zhao, D., Chen, Z., and Liu, K.
1989. The Phosphorites of China. Science Press, Beijing. 339 p.Google Scholar
Yin, C.
1990. Spinose acritarchs from the Toushantuo Formation and its geological significance. Acta Micropalaeontologica Sinica, 7:265–270.Google Scholar
Yin, C., and Gao, L.
1995. The early evolution of the acanthomorphic acritarchs in China and their biostratigraphic implication. Acta Geologica Sinica, 469:360–373.Google Scholar
Yin, L.
1985. Microfossils of the Doushantuo Formation in the Yangtze Gorge district, western Hubei. Palaeontologia Cathayana, 2:229–249.Google Scholar
Yin, L.
1987. Microbiotas of latest Precambrian sequences in China, p. 415–494. In
Nanjing Institute of Geology and Palaeontology A. S. (ed.), Stratigraphy and Palaeontology of Systemic Boundaries in China: Precambrian-Cambrian Boundary (1). Nanjing University Press, Nanjing.Google Scholar
Yin, L., and Li, Z.
1978. Precambrian microfloras of southwest China with reference to their stratigraphic significance. Memoir Nanjing Institute of Geology and Palaeontology, Academia Sinica, 10:41–108.Google Scholar
Yin, L., and Xue, Y.
1993. An extraordinary microfossil assemblage from terminal Proterozoic phosphate deposits in south China. Chinese Journal of Botany, 5(2):168–175Google Scholar
Yuan, X., and Hofmann, H. H.
1998. New microfossils from the Neoproterozoic (Sinian) Doushantuo Formation, Weng'an, Guizhou Province, southwestern China. Alcheringa, 22:189–222.Google Scholar
Yuan, X., Li, J., and Chen, M.
1995. Development and their fossil records of metaphytes from late Precambrian. Acta Palaeontologica Sinica, 34(1):90–102Google Scholar
Yuan, X., Li, J., and Cao, R.
1999. A diverse metaphyte assemblage from the Neoproterozoic black shales of South China. Lethaia, 32:143–155.Google Scholar
Yue, Z.
1986. Microstructure and systematic position of Olivooides (Porifera). Bulletin of the Institute of Geology, Chinese Academy of Geological Sciences, no. 14:147–152.Google Scholar
Yue, Z., and Bengtson, S.
1999. Embryonic and post-embryonic development of the Early Cambrian cnidarian Olivooides
. Lethaia, 32:181–195.Google Scholar
Zang, W., and Walter, M. R.
1992. Late Proterozoic and Cambrian microfossils and biostratigraphy, Amadeus Basin, central Australia. Association of Australasian Palaeontologists Memoir, 12:1–132.Google Scholar
Zhang, X., and Pratt, B. R.
1994. Middle Cambrian Arthropod embryos with blastomeres. Science, 266:637–639.CrossRefGoogle ScholarPubMed
Zhang, Y.
1989. Multicellular thallophytes with differentiated tissues from late Proterozoic phosphate rocks of South China. Lethaia, 22:113–132.Google Scholar
Zhang, Y., Yin, L., Xiao, S., and Knoll, A. H.
1998. Permineralized fossils from the Terminal Proterozoic Doushantuo Formation, South China. The Paleontological Society, Memoir
50, 52p.Google Scholar
Zhang, Y., and Yuan, X.
1992. New data on multicellular thallophytes and fragments of cellular tissues from Late Proterozoic phosphate rocks, South China. Lethaia, 25:1–18.Google Scholar
Zhang, Y., Yuan, X., and Yin, L.
1998. Interpreting Late Precambrian Microfossils. Science, 282:1783.CrossRefGoogle Scholar
Zhang, Z.
1984. Microflora of the late Sinian Doushantuo Formation, Hubei Province, China, p. 129–140. In
Xie, L. and Zhang, J. (ed.), Scientific Papers on Geology for International Exchange—Prepared for the 27th International Geological Congress, 1984, Moscow, vol. 1. Geological Publishing House, Beijing.Google Scholar
Zhao, Z., Xing, Y., Ma, G., and Chen, Y.
1985. Biostratigraphy of the Yangtze Gorge Area, (1) Sinian. Geological Publishing House, Beijing, 143 p.Google Scholar
Zhao, Z., Xing, Y., Ma, G., Yu, W., and Wang, Z.
1980. The Sinian System of eastern Yangtze Gorges, Hubei, p. 31–55. In
Resources, T. I. o. G. a. M. (ed.), Research in Precambrian Geology, Sinian Suberathem in China. Tianjin Science and Technology Press, Tianjin.Google Scholar
Zhao, Z., Xing, Y., Ding, Q., Liu, G., Zhao, Y., Zhang, S., Meng, X., Yin, C., Ning, B., and Han, P.
1988. The Sinian System of Hubei. China University of Geosciences Press, Wuhan. 205 p.Google Scholar
Zhou, C.
1997. Upper Sinian carbon isotope profile in Weng'an, Guizhou. Journal of Stratigraphy, 21:125–129.Google Scholar
Zhou, C., Xue, Y., and Zhang, J.
1998. Stratigraphy and sedimentary environment of the Upper Sinian Doushantuo Formation in Weng'an phosphorite deposit, Guizhou Province. Journal of Stratigraphy, 22:308–314.Google Scholar
Zhu, W., and Chen, M.
1984. On the discovery of macrofossil algae from the late Sinian in the eastern Yangtze Gorges, south China. Acta Botanica Sinica, 26(5):558–560Google Scholar
Zhuravlev, A. Y., and Wood, R. A.
1996. Anoxia as the cause of the mid-Early Cambrian (Botomian) extinction event. Geology, 24:311–314.2.3.CO;2>CrossRefGoogle Scholar