Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-23T17:57:53.479Z Has data issue: false hasContentIssue false
  • English
  • Français

Were the Ediacaran fossils lichens?

Published online by Cambridge University Press:  08 February 2016

Gregory J. Retallack
Gregory J. Retallack*
Affiliation:
Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403
Get access Rights & Permissions [Opens in a new window]

Abstract

Ediacaran fossils are taphonomically similar to impressions of fossil plants common in quartz sandstones, and the relief of the fossils suggests that they were as resistant to compaction during burial as some kinds of Pennsylvanian tree trunks. Fossils of jellyfish are known from siderite nodules and fine-grained limestone, and even in these compaction-resistant media were more compressed during burial than were the Vendobionta. Vendobionta were constructed of materials that responded to burial compaction in a way intermediate between conifer and lycopsid logs. This comparative taphonomic study thus falsifies the concept of Vendobionta as thin soft-bodied creatures such as worms and jellyfish.

Lichens, with their structural chitin, present a viable model for the observed preservational style of Vendobionta, as well as for a variety of other features that now can be reassessed from this new perspective. The diversity of Ediacaran body plans can be compared with the variety of form in fungi, algae, and lichens. The large size (ca. 1 m) of some Ediacaran fossils is reasonable for sessile photosynthetic symbioses, and much bigger than associated burrows of metazoans not preserved. Microscopic tubular structures and darkly pigmented cells in permineralized late Precambrian fossils from Namibia and China are also compatible with interpretation as lichens. The presumed marine habitat of Ediacaran fossils is not crucial to interpretation as lichens, because fungi and lichens live in the sea as well as on land.

Type
Research Article
Information
Paleobiology , Volume 20 , Issue 4 , Fall 1994 , pp. 523 - 544
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Anderson, J. M. 1977. The biostratigraphy of the Permian and Triassic. Part 3. A review of Gondwana Permian palynology with particular reference to the northern Karoo Basin, South Africa. Memoirs of the Botanical Survey of South Africa 41.Google Scholar
Anderson, J. M., and Anderson, H. M. 1985. Palaeoflora of southern Africa: Prodromus of South Africa megafloras, Devonian to Lower Cretaceous. Balkema, Rotterdam.Google Scholar
Anderson, M. J., and Conway Morris, S. 1982. A review, with descriptions of four unusual forms, of the soft-bodied fauna of the Conception and St. John's Groups (Late Precambrian), Avalon Peninsula, Newfoundland. Proceedings of the Third North American Paleontological Convention, Montreal 1:1–8.Google Scholar
Barghoorn, E. S. 1981. Aspects of Precambrian paleobiology: the early Precambrian. Pp. 1–16in Niklas, K. J., ed. Paleobotany, paleoecology and evolution, Vol. 1. Praeger, New York.Google Scholar
Beaumont, C., Quinlan, G., and Hamilton, J. 1987. The Alleghanian Orogeny and its relationship to the evolution of the eastern Interior, North America. Pp. 425–445in Beaumont, C. and Tankard, A. J., eds. Sedimentary basins and basin-forming mechanisms. Memoir of the Canadian Society for Petroleum Geology 12.Google Scholar
Beckett, A., Heath, I. B., and McLauglin, D. J. 1974. An atlas of fungal ultrastructure. Longman, London.Google Scholar
Bengston, S. 1992. Proterozoic and earliest Cambrian skeletal metazoans. Pp. 397–411in Schopf, J. W. and Klein, C., eds. The Proterozoic biosphere. Cambridge University Press, New York.Google Scholar
Benus, A. P. 1988. Sedimentological context of deep-water Ediacaran fauna (Mistaken Point Formation, Avalon zone, eastern Newfoundland). P. 8in Landing, E., Narbonne, G. M., and Myrow, P., eds. Trace fossils, small shelly fossils and the Precambrian-Cambrian boundary. Bulletin of the New York State Museum 463.Google Scholar
Bergström, J. 1990. Precambrian trace fossils and the rise of bilaterian animals. Ichnos 1:3–13.CrossRefGoogle Scholar
Briggs, D. E. G., and Williams, S. H. 1981. The restoration of flattened fossils. Lethaia 14:157–164.CrossRefGoogle Scholar
Bruton, D. L. 1991. Beach and laboratory experiments with the jellyfish Amelia and remarks on some fossil “medusoid” traces. Pp. 125–129in Simonetta, A. B. and Morris, S. C., eds. The early evolution of Metazoa and the significance of problematic taxa. Cambridge University Press, Cambridge.Google Scholar
Burgess, N., and Edwards, D. 1988. A new Palaeozoic plant closely allied to Prototaxites Dawson. Botanical Journal of the Linnaean Society of London 97:189–203.CrossRefGoogle Scholar
Burns, J. 1991. Fossil collecting in the mid-Atlantic states. Johns Hopkins University Press, Baltimore.CrossRefGoogle Scholar
Cain, R. F. 1972. Evolution of the fungi. Mycologia 64:1–14.CrossRefGoogle Scholar
Cardwell, D. H., Erwin, R. B., Woodward, H. P., and Lotz, C. W. 1986. Geologic map of West Virginia. West Virginia Geological Survey, Mont Chateau, West Virginia.Google Scholar
Cloud, P. 1976. The beginnings of biospheric evolution and their biochemical consequences. Paleobiology 2:351–387.CrossRefGoogle Scholar
Conway Morris, S. 1993. The fossil record and the early evolution of the Metazoa. Nature (London) 361:219–225.CrossRefGoogle Scholar
Crimes, T. P., and Anderson, M. M. 1985. Trace fossils from the Early Cambrian strata of southeastern Newfoundland (Canada): temporal and environmental implications. Journal of Paleontology 59:310–343.Google Scholar
Daily, B. 1957. The Cambrian in South Australia. Pp. 91–147in Opik, A. A., ed. The Cambrian geology of Australia. Bulletin of the Bureau of Mineral Resources 49.Google Scholar
Dawson, J. B. 1870. The primitive vegetation of the Earth. Nature (London) 2:85–88.CrossRefGoogle Scholar
Des Marais, D. J., Strauss, H., Summons, R. E., and Hayes, J. M. 1992. Carbon isotopic evidence for the stepwise oxidation of the Proterozoic environment. Nature (London) 359:605–609.CrossRefGoogle ScholarPubMed
Eldredge, N. 1991. Fossils. Abrams, New York.Google Scholar
Fedonkin, M. A. 1981. Byelomorskaya biota Vend (White Sea biota of Vendian). Trudy Geologicheskii Institut Akademia Nauk S.S.S.R., Moscow342.Google Scholar
Fedonkin, M. A. 1992. Vendian faunas and the early evolution of Metazoa. Pp. 187–229in Lipps, J. H. and Signor, P. W., eds. Origin and early evolution of the Metazoa. Plenum, New York.Google Scholar
Fedonkin, M. A., and Runnegar, B. N.Proterozoic metazoan trace fossils. Pp. 389–410in Schopf, J. W. and Klein, C., eds. The Proterozoic biosphere. Cambridge University Press, New York.Google Scholar
Fleming, P. J. G., and Rigby, J. F. 1972. Possible land plants from the Middle Cambrian, Queensland. Nature (London) 238:266.CrossRefGoogle Scholar
Ford, T. D. 1958. Precambrian fossils from Charnwood Forest. Proceedings of the Yorkshire Geological Society 31:211–217.CrossRefGoogle Scholar
Foster, M. W. 1979. Soft bodied coelenterates in the Pennsylvanian of Illinois. Pp. 191–267in Nitecki, M. H., ed. Mazon Creek fossils. Academic Press, New York.CrossRefGoogle Scholar
Frarey, M. J., and McLaren, D. J. 1963. Possible metazoans from the early Proterozoic of the Canadian Shield. Nature (London) 200:461–462.CrossRefGoogle Scholar
Galun, M., Braun, A., Frensdorff, A., and Galun, E. 1976. Hyphal walls of isolated lichen fungi. Archives of Microbiology 108:9–16.CrossRefGoogle Scholar
Gehling, J. G. 1988. A cnidarian of actinian-grade from the Ediacaran Pound Subgroup, South Australia. Alcheringa 12:299–314.CrossRefGoogle Scholar
Gensel, P. G., Chaloner, W. G., and Forbes, W. H. 1991. Spongiophyton from the Late Lower Devonian of New Brunswick and Quebec, Canada. Palaeontology 34:149–168.Google Scholar
Gibson, G. G., Teeter, S. A., and Fedonkin, M. A. 1984. Ediacaran fossils from the Carolina Slate Belt, Stanly County, North Carolina. Geology 12:387–390.2.0.CO;2>CrossRefGoogle Scholar
Gillespie, W. H., Clendening, J. A., and Pfefferkorn, H. W. 1978. Plant fossils of West Virginia. Educational Series of the West Virginia Geological Survey ED-3A.Google Scholar
Glaessner, M. F. 1984. The dawn of animal life. Cambridge University Press, Cambridge.Google Scholar
Gould, S. J. 1984. The Ediacaran experiment. Natural History 93:14–23.Google ScholarPubMed
Gray, J., Massa, D., and Boucot, A. 1982. Caradocian land plant microfossils from Libya. Geology 10:197–201.2.0.CO;2>CrossRefGoogle Scholar
Hale, M. E. 1983. The biology of lichens. Edward Arnold, London.Google Scholar
Hallbauer, D. K., and van Warmelo, K. T. 1974. Fossilized plants in thucolite from the Precambrian rocks of the Witwatersrand, South Africa. Precambrian Research 1:199–212.CrossRefGoogle Scholar
Hallbauer, D. K., Jahns, M. H., and Beltmann, H. A. 1977. Morphological and anatomical observations on some Precambrian plants from the Witwatersrand, South Africa. Geologische Rundschau 66:477–491.CrossRefGoogle Scholar
Harland, W. B. 1983. The Proterozoic glacial record. Pp. 279–288in Medaris, L. G., Byers, C. W., Mickleson, D. M., and Shanks, W. C., eds. Proterozoic geology: selected papers from an international Proterozoic symposium. Memoirs of the Geological Society of America 161.Google Scholar
Hartmann, W. K., and Miller, R. 1991. The history of Earth. Workman, New York.Google Scholar
Hawker, C. E., and Madelin, M. F. 1976. The dormant spore. Pp. 1–70in Weber, D. J. and Hess, W. M., eds., The fungal spore. Wiley, New York.Google Scholar
Hawksworth, D. L. 1988a. The fungal partner. Pp. 25–38in Galun, M., ed. Handbook of lichenology, Vol. 1. CRC Press, Boca Raton, Fla.Google Scholar
Hawksworth, D. L. 1988b. The variety of fungal-algal symbioses, their evolutionary significance, and the nature of lichens. Botanical Journal of the Linnaean Society of London 96:3–20.CrossRefGoogle Scholar
Herrera, J. R. 1992. Fungal cell wall: structure, synthesis and assembly. CRC Press, Boca Raton, Fla.Google Scholar
Hickman, C.J. 1965. Fungal structure and organization. Pp. 21–45in Ainsworth, G. C. and Sussman, A. S., eds. The fungi, Vol. 1. The fungal cell. Academic Press, New York.Google Scholar
Hofmann, H. J. 1967. Precambrian fossils (?) near Elliot Lake, Ontario. Science 156:500–504.CrossRefGoogle ScholarPubMed
Hofmann, H. J. 1971. Precambrian fossils, pseudofossils and problematica in Canada. Bulletin of the Geological Survey of Canada 189:1–146.Google Scholar
Hofmann, H. J. 1992. Megascopic dubiofossils. Pp. 413–419in Schopf, J. W. and Klein, C., eds. The Proterozoic biosphere. Cambridge University Press, New York.Google Scholar
Holland, H. D. 1992. Distribution and paleoenvironmental interpretation of Proterozoic paleosols. Pp. 153–155in Schopf, J. W. and Klein, C., eds. The Proterozoic biosphere. Cambridge University Press, New York.Google Scholar
Horodyski, R. J. 1991. Late Proterozoic megafossils from southern Nevada. Abstracts of the Annual Meeting of the Geological Society of America 23:A163.Google Scholar
Jenkins, R. J. F. 1985. The enigmatic Ediacaran (late Precambrian) genus Rangea and related forms. Paleobiology 11:336–355.CrossRefGoogle Scholar
Jenkins, R. J. F. 1992. Functional and ecological aspects of Ediacaran assemblages. Pp. 131–176in Lipps, J. H. and Signor, P. W., eds. Origin and early evolution of the Metazoa. Plenum, New York.CrossRefGoogle Scholar
Jenkins, R. J. F., Ford, C. H., and Gehling, J. G. 1983. The Ediacara Member of the Rawnsley Quartzite: the context of the Ediacara assemblage (late Precambrian, Flinders Ranges). Journal of the Geological Society of Australia 30:101–119.CrossRefGoogle Scholar
Jennings, J. R. 1974. Lower Pennsylvanian flora of Illinois. 1. A flora from the Pounds Sandstone Member of the Caseyville Formation. Journal of Paleontology 49:459–472.Google Scholar
Jonker, F. P. 1979. Prototaxites in the Lower Devonian. Palaeontographica B171:551–562.Google Scholar
Kasting, J. F. 1987. Theoretical constraints on oxygen and carbon dioxide concentrations in Earth's early atmosphere. Precambrian Research 20:121–148.CrossRefGoogle Scholar
Katsaros, P. 1990. Familiar mushrooms. Knopf, New York.Google Scholar
Kent, L. E., ed. 1980. Stratigraphy of South Africa. Handbook of the Geological Survey of South Africa 8.Google Scholar
Knoll, A. H. 1985. Exceptional preservation of photosynthetic organisms in silicified carbonates and silicified peats. Philosophical Transactions of the Royal Society of London B31:111–122.Google Scholar
Knoll, A. H. 1992. The early evolution of eukaryotes: a geological perspective. Science 256:622–627.CrossRefGoogle ScholarPubMed
Kohlmeyer, J., and Kohlmeyer, E. 1979. Marine mycology. Academic Press, New York.Google Scholar
Lange, R. T. 1978. Carpological evidence for fossil Eucalyptus and other Leptospermae (sub-family Leptospermoideae of Myrtaceae) from a Tertiary deposit in the South Australian arid zone. Australian Journal of Botany 26:221–233.CrossRefGoogle Scholar
Lewin, R. 1984. Alien beings here on earth. Science 223:39.CrossRefGoogle ScholarPubMed
Mackay, R. M. 1964. Lepidophloios and Cyrtospirifer from the Lambie Group at Mount Lambie, N.S.W. Journal of the Royal Society of New South Wales 97:83–89.CrossRefGoogle Scholar
Margulis, L., and Schwartz, K. V. 1982. Five kingdoms. W.H. Freeman, San Francisco.Google Scholar
McMenamin, M. A. S. 1986. The garden of Ediacara. Palaios 1:178–182.CrossRefGoogle Scholar
McMenamin, M. A. S. 1992. Subaerial plants in the Proterozoic. Abstracts of the Annual Meeting of the Northeastern Section of the Geological Society of America 24:62.Google Scholar
Mendelson, C. V., and Schopf, J. W. 1992. Proterozoic and selected early Cambrian microfossils and microfossil-like objects. Pp. 865–951in Schopf, J. W. and Klein, C., eds. The Proterozoic biosphere. Cambridge University Press, New York.CrossRefGoogle Scholar
Milnes, A. A., and Thiry, M. 1992. Silcretes. Pp. 342–377in Martini, I. P. and Chesworth, W., eds. Weathering, soils and paleosols. Elsevier, Amsterdam.Google Scholar
Müller, K. J., and Hinz, I. 1992. Cambrogeorginidae fam. nov., soft-integumented Problematica from the Middle Cambrian of Australia. Alcheringa 16:333–353.CrossRefGoogle Scholar
Narbonne, G. M., and Aitken, J. D. 1990. Ediacaran fossils from the Sekwi Brook area, Mackenzie Mountains, northwestern Canada. Palaeontology 33:945–980.Google Scholar
Niklas, K. J. 1976a. Chemotaxonomy of Prototaxites and evidence for possible terrestrial adaptation. Review of Palaeobotany and Palynology 22:1–17.CrossRefGoogle Scholar
Niklas, K. J. 1976b. Organic chemistry of Protosalvinia (=Foerstia) from the Chattanooga and New Albany Shales. Review of Palaeobotany and Palynology 22:265–279.CrossRefGoogle Scholar
Niklas, K. J., and Phillips, T. L. 1976. Morphology of Protosalvinia from the upper Devonian of Ohio and Kentucky. American Journal of Botany 63:9–29.CrossRefGoogle Scholar
Niklas, K. J., and Smocovitis, V. 1983. Evidence for a conducting strand in Early Silurian (Llandoverian) plants: implications for the evolution of land plants. Paleobiology 9:126–137.CrossRefGoogle Scholar
Norris, R. D. 1989. Cnidarian taphonomy and affinities of the Ediacara biota. Lethaia 22:381–393.CrossRefGoogle Scholar
Percival, C. J. 1986. Paleosols containing an albic horizon: examples from the upper Carboniferous of northern England. Pp. 87–111in Wright, V. P., ed. Paleosols: their recognition and interpretation. Blackwell, Oxford.Google Scholar
Peters, M. D., and Christophel, D. C. 1978. Austrosequoia wintonensis, a new taxodiaceous cone from Queensland, Australia. Canadian Journal of Botany 56:3119–3128.CrossRefGoogle Scholar
Pflug, H. D. 1973. Zur fauna der Nama-Schichten in Südwest-Afrika. IV. Mikroscopische anatomie der petalo-organisme. Palaeontographica B144:166–202.Google Scholar
Phillips, R. 1980. Grasses, ferns, mosses and lichens of Great Britain and Ireland. Pan Books, London.Google Scholar
Ramkaer, K. 1977. The influence of salinity on the establishing phase of rocky shore lichens. Botanisk Tiddsskrift 72:119–123.Google Scholar
Rauh, W. 1985. The Peruvian-Chilean deserts. Pp. 239–267in Evenari, M., Noy-Meir, I., and Goodall, D. W., eds. Hot deserts and arid shrublands. Elsevier, Amsterdam.Google Scholar
Retallack, G. J. 1984. Completeness of the rock and fossil record: estimates using fossil soils. Paleobiology 10:59–78.CrossRefGoogle Scholar
Retallack, G. J. 1988. Field recognition of paleosols. Pp. 1–20in Reinhardt, J. and Sigleo, W. R., eds. Paleosols and weathering through geologic time: principles and applications. Special Paper of the Geological Society of America 216.Google Scholar
Retallack, G. J. 1990. Soils of the past. Unwin-Hyman, London.CrossRefGoogle Scholar
Retallack, G. J. 1992a. Paleozoic paleosols. Pp. 543–564in Martini, P., ed. Weathering, soil and paleosols. Elsevier, Amsterdam.CrossRefGoogle Scholar
Retallack, G. J. 1992b. What to call early plant formations on land. Palaios 7:508–520.CrossRefGoogle Scholar
Retallack, G. J. 1992c. Were the Ediacaran fossils lichenlike organisms? Abstracts of the Geological Society of America 24:A226–A227.Google Scholar
Rex, G. M., and Chaloner, W. G. 1983. The experimental deformation of plant compression fossils. Palaeontology 26:231–252.Google Scholar
Ritchie, A. 1973. Wuttagoonaspis gen. nov., an unusual arthrodire from the Devonian of western New South Wales, Australia. Palaeontographica A143:58–72.Google Scholar
Robison, R. A., and Hintze, L. F. 1972. An early Cambrian trilobite faunule from Utah. Brigham Young University Geology Studies 19:3–15.Google Scholar
Rowe, N. P. 1988. Two species of the lycophyte genus Eskdalia Kidston from the Drybook Sandstone (Visean) of Great Britain. Palaeontographica B208:81–103.Google Scholar
Runnegar, B. N. 1982. Oxygen requirements, a biology and phylogenetic significance of the late Precambrian worm Dickinsonia and the evolution of the burrowing habit. Alcheringa 6:223–239.CrossRefGoogle Scholar
Runnegar, B. N. 1992. Evolution of the earliest animals. Pp. 65–93in Schopf, J. W., ed. Major events in the history of life. Jones and Bartlett, Boston.Google Scholar
Runnegar, B. N., and Fedonkin, M. A. 1992. Proterozoic metazoan body fossils. Pp. 369–388in Schopf, J. W. and Klein, C., eds. The Proterozoic biosphere. Cambridge University Press, New York.Google Scholar
Scagel, F. F., Bandoni, R. J., Rouse, G. E., Schofield, W. B., Stein, J. R., and Taylor, T. M. C. 1965. An evolutionary survey of the plant kingdom. Wadsworth, Belmont, Calif.Google Scholar
Schmid, R. 1976. Septal pores in Prototaxites, an enigmatic Devonian plant. Science 191:287–288.CrossRefGoogle ScholarPubMed
Schopf, J. M. 1975. Modes of fossil preservation. Review of Palaeobotany and Palynology 20:27–53.CrossRefGoogle Scholar
Schopf, J. M. 1979. Evidence of soft-sediment cementation enclosing Mazon plant fossils. Pp. 105–128in Nitecki, M. H., ed. Mazon Creek Fossils. Academic Press, New York.CrossRefGoogle Scholar
Schopf, J. M. 1992. Atlas of representative Proterozoic microfossils. Pp. 1057–1117in Schopf, J. W. and Klein, C., eds. The Proterozoic biosphere. Cambridge University Press, New York.CrossRefGoogle Scholar
Schopf, J. W., and Barghoorn, E. S. 1969. Microorganisms from the Late Precambrian of South Australia. Journal of Paleontology 43:111–118.Google Scholar
Schweitzer, H. J. 1983. Der Unterdevonflora des Rheinlandes. I. Teil. Palaeontographica B189:1–138.Google Scholar
Seilacher, A. 1984. Late Precambrian and Early Cambrian Metazoa: preservational or real extinctions? Pp. 159–168in Holland, H. D. and Trendall, A. F., eds. Patterns of change in earth evolution. Springer, Berlin.CrossRefGoogle Scholar
Seilacher, A. 1985. Discussion of Precambrian metazoans. Philosophical Transactions of the Royal Society of London B311:47–48.Google Scholar
Seilacher, A. 1989. Vendozoa: organismic construction in the Proterozoic biosphere. Lethaia 22:229–239.CrossRefGoogle Scholar
Seilacher, A. 1992. Vendobionta and Psammocorallia: lost constructions of Precambrian evolution. Journal of the Geological Society of London 149:607–613.CrossRefGoogle Scholar
Sepkoski, J. J. Jr. 1992. Proterozoic-Early Cambrian diversification of metazoans and metaphytes. Pp. 553–561in Schopf, J. W. and Klein, C., eds. The Proterozoic biosphere. Cambridge University Press, New York.Google Scholar
Sherwood-Pike, M. A. 1985. Pelicothallus Dilcher, an overlooked fossil lichen. Lichenologist 17:114–115.CrossRefGoogle Scholar
Sherwood-Pike, M. A., and Gray, J. 1985. Silurian fungal remains: probable records of Ascomycetes. Lethaia 19:1–20.CrossRefGoogle Scholar
Smith, A. L. 1921. Lichens. Cambridge University Press, Cambridge.CrossRefGoogle Scholar
Sokolov, B. S., and Iwanowski, A. B., eds. 1990. The Vendian system, Vol. 1. Paleontology. Springer, Berlin.Google Scholar
Sprigg, R. C. 1947. Early Cambrian (?) jellyfishes from the Flinders Ranges, South Australia. Transactions of the Royal Society of South Australia 71:212–224.Google Scholar
Stein, W. E., Harmon, G. D., and Heuber, F. M. 1993. Lichens in the Lower Devonian of North America. Abstracts of the Annual Meeting of the Geological Society of America 25:A82.Google Scholar
Stewart, W. N. 1983. Paleobotany and the evolution of plants. Cambridge University Press, Cambridge.Google Scholar
Strother, P. K. 1988. New species of Nematothallus from the Silurian Bloomsburg Formation of Pennsylvania. Journal of Paleontology 62:967–982.CrossRefGoogle Scholar
Stubblefield, S. F., and Taylor, T. N. 1988. Recent advances in palaeomycology. New Phytologist 108:3–25.CrossRefGoogle ScholarPubMed
Summerfield, M. A. 1983. Petrography and diagenesis of silcrete from the Kalahari Basin and Cape coastal zone, southern Africa. Journal of Sedimentary Petrology 53:895–909.Google Scholar
Taylor, J. M. 1950. Pore-space reduction in sandstone. Bulletin of the American Association of Petroleum Geologists 34:701–706.Google Scholar
Taylor, W. A., and Taylor, T. N. 1987. Spore wall ultrastructure of Protosalvinia. American Journal of Botany 74:437–443.CrossRefGoogle Scholar
Taylor, T. N., and Taylor, E. L. 1993. The biology and evolution of fossil plants. Prentice Hall, Englewood Cliffs, New Jersey.Google Scholar
Valentine, J. 1992. Dickinsonia as a polypoid organism. Paleobiology 18:378–382.CrossRefGoogle Scholar
Van der Plas, L., and Tobi, A. C. 1965. A chart for judging the reliability of point count results. American Journal of Science 263:87–90.CrossRefGoogle Scholar
Wade, M. 1968. Preservations of soft-bodied animals in Precambrian sandstones at Ediacara, South Australia. Lethaia 1:238–267.CrossRefGoogle Scholar
Walter, H. 1985. The Namib desert. Pp. 245–282in Evenari, M., Noy-Meir, I., and Goodall, D. W., eds. Hot deserts and arid shrublands. Elsevier, Amsterdam.Google Scholar
Walton, J. 1936. On the factors which influence the external form of fossil plants; with description of some specimens of the Paleozoic equisetalean genus Annularia Sternberg. Philosophical Transactions of the Royal Society of London B226:219–237.Google Scholar
White, M. E. 1986. The Greening of Gondwana. Reed, Frenchs Forest, New South Wales, Australia.Google Scholar
Zhang, Y., and Yuan, X.-L. 1992. New data on multicellular thallophytes and fragments of cellular tissues from Late Proterozoic rocks, South China. Lethaia 25:1–18.Google Scholar
Zhuralev, A. Y. 1992. Were Vend-Ediacaran multicellulars Metazoa? Abstracts of the International Geological Congress, Kyoto, Japan 2:339.Google Scholar