Paleobiology

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Paleobiology 33(3):351-381. 2007
doi: 10.1666/04040.1

The Paleoproterozoic megascopic Stirling biota

Stefan Bengtsona, Birger Rasmussenb, Bryan Krapežb

aStefan Bengtson.Department of Palaeozoology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden.

bBirger Rasmussen and Bryan Krapež.School of Earth and Geographical Sciences, The University of Western Australia, Crawley 6009, Western Australia, Australia. and

Abstract

The 2.0–1.8-billion-year-old Stirling Range Formation in southwestern Australia preserves the deposits of a siliciclastic shoreline formed under the influence of storms, longshore currents, and tidal currents. Sandstones contain a megascopic fossil biota represented by discoidal fossils similar to the Ediacaran Aspidella Billings, 1872, as well as ridge pairs preserved in positive hyporelief on the soles of channel-fill sandstones bounded by mud drapes. The ridges run parallel or nearly parallel for most of their length, meeting in a closed loop at one end and opening with a slight divergence at the opposite end. The ridges are interpreted as casts of sediment-laden mucus strings formed by the movement of multicellular or syncytial organisms along a muddy surface. The taxa Myxomitodes stirlingensis n. igen., n. isp., are introduced for these traces. The Stirling biota was roughly coeval with other presumed multicellular eukaryotes appearing after a long period of profound environmental changes involving a rise in ambient oxygen levels, similar to that which preceded the Cambrian explosion. The failure of multicellular life to diversify during most of the Proterozoic may be due to environmental constraints related to the comparatively low level of oxidation of the world oceans.

Accepted: May 4, 2007



Literature Cited

Aharon, P. 2005. Redox stratification and anoxia of the early Precambrian oceans: implications for carbon isotope excursions and oxidation events. Precambrian Research 137:207–222.
Anbar, A. D. and A. H. Knoll. 2002. Proterozoic ocean chemistry and evolution: a bioinorganic bridge? Science 297:1137–1142. CrossRef, PubMed, CSA
Aris-Brosou, S. and Z. Yang. 2002. Effects of models of rate evolution on estimation of divergence dates with special reference to the metazoan 18S ribosomal RNA phylogeny. Systematic Biology 51:703–714. CrossRef, PubMed, CSA
Arnold, G. L., A. D. Anbar, J. Barling, and T. W. Lyons. 2004. Molybdenum isotope evidence for widespread anoxia in mid-Proterozoic oceans. Science 304:87–90. CrossRef, PubMed
Ayala, F. J. 1999. Molecular clock mirages. BioEssays 21:71–75. CrossRef, PubMed, CSA
Ayala, F. J., A. Rzhetsky, and F. J. Ayala. 1998. Origin of the metazoan phyla: molecular clocks confirm paleontological estimates. Proceedings of the National Academy of Sciences USA 95:606–611. CrossRef, PubMed, CSA
Baldauf, S. L., A. J. Roger, I. Wenk-Siefert, and W. F. Doolittle. 2000. A kingdom-level phylogeny of eukaryotes based on combined protein data. Science 290:972–977. CrossRef, PubMed, CSA
Beeson, J. 1991. A field and experimental study of structures in the Albany Mobile Belt, Western Australia. Ph.D. thesis. University of Western Australia, Perth.
Bengtson, S. 2002. Origins and early evolution of predation. In M. Kowalewski and P. H. Kelley, eds. The fossil record of predation. Paleontological Society Special Papers 8:289–317.
Beninger, P. G., J. W. Lynn, T. H. Dietz, and H. Silverman. 1997. Mucociliary transport in living tissue: the two-layer model confirmed in the mussel Mytilus edulis L. Biological Bulletin 193:4–7. CrossRef, CSA
Bjerrum, C. J. and D. E. Canfield. 2002. Ocean productivity before about 1.9 Gyr ago limited by phosphorous adsorption onto iron oxides. Nature 417:159–162. CrossRef, PubMed, CSA
Blair, J. E. and S. B. Hedges. 2005. Molecular clocks do not support the Cambrian explosion. Molecular Biology and Evolution 22:387–390. CrossRef, PubMed
Bölücek, C. and B. Ilhan. 2006. A survey of pyritised animal, plant, and trace fossils and concretionary pyrites, Germav Formation, southeastern Turkey. Comptes Rendus Geoscience 338:161–171. CrossRef
Bonner, J. T. 2000. First signals: the evolution of development. Princeton University Press, Princeton, N.J.
Boulter, C. A. 1979. On the production of two inclined cleavages during a single folding event; Stirling Range, S.W. Australia. Journal of Structural Geology 1:207–219. CrossRef
Bourlat, S. J., C. Nielsen, A. E. Lockyer, D. T J. Littlewood, and M. J. Telford. 2003. Xenoturbella is a deuterostome that eats molluscs. Nature 424:925–928. CrossRef, PubMed, CSA
Breen, E. J., P. H. Vardy, and K. L. Williams. 1987. Movement of the multicellular slug stage of Dictyostelium discoideum: an analytical approach. Development 101:313–3322. CSA
Breyer, J. A., A. B. Busbey, R. E. Hanson, and E. C I. Roy. 1995. Possible new evidence for the origin of metazoans prior to 1 Ga: sediment-filled tubes from the Mesoproterozoic Allamoore Formation, Trans-Pecos Texas. Geology 23:269–272. CrossRef, CSA
Brocks, J. J., G. A. Logan, R. Buick, and R. E. Summons. 1999. Archean molecular fossils and the early rise of eukaryotes. Science 285:1033–1036. CrossRef, PubMed, CSA
Bromley, R. 1996. Trace fossils, 2d ed. Chapman and Hall, London.
Buatois, L. A., M. G. Mángano, C. G. Maples, and W. P. Lanier. 1998. Taxonomic reassessment of the ichnogenus Beaconichnus and additional examples from the Carboniferous of Kansas, U.S.A. Ichnos 5:287–302. CrossRef
Budd, G. E. and S. Jensen. 2000. A critical reappraisal of the fossil record of the bilaterian phyla. Biological Reviews 75:253–295. CrossRef, PubMed, CSA
Budd, G. E. and S. Jensen. 2003. The limitations of the fossil record and the dating of the origin of the Bilateria. Pp. 166–189 in P. C. J. Donoghue, ed. Telling the evolutionary time: molecular clocks and the fossil record. Taylor and Francis, London.
Butterfield, N. J. 2000. Bangiomorpha pubescens n. gen., n. sp.: implications for the evolution of sex, multicellularity, and the Mesoproterozoic/Neoproterozoic radiation of eukaryotes. Paleobiology 26:386–404. Abstract, CSA
Butterfield, N. J. 2004. A vaucheriacean alga from the middle Neoproterozoic of Spitsbergen: implications for the evolution of Proterozoic eukaryotes and the Cambrian explosion. Paleobiology 30:231–252. Abstract
Canfield, D. E. and R. Raiswell. 1991. Pyrite formation and fossil preservation. Pp. 337–387 in P. A. Allison, and D. E. G. Briggs, eds. Taphonomy: releasing the data locked in the fossil record. Plenum, New York.
Canfield, D. E. and A. Teske. 1996. Late Proterozoic rise in atmospheric oxygen concentration inferred from phylogenetic and sulphur-isotope studies. Nature 382:127–132. CrossRef, PubMed, CSA
Cavalier-Smith, T. 1987. The origin of eukaryote and archaebacterial cells. Annals of the New York Academy of Sciences 503:17–54. CrossRef, PubMed
Cavender, J. S. 1990. Phylum Dictyostelida. Pp. 88–101 in Margulis et al. 1990.
Clemmey, H. 1976. World's oldest animal traces. Nature 261:576–578. CrossRef
Cloud, P. 1973. Pseudofossils: a plea for caution. Geology 1:123–127. CrossRef
Collins, A. G., J. H. Lipps, and J. W. Valentine. 2000. Modern mucociliary creeping trails and the bodyplans of Neoproterozoic trace-makers. Paleobiology 26:47–55. Abstract, CSA
Conway Morris, S. 2002. Ancient animals or something else entirely? Science 298:57–58. CrossRef
Conway Morris, S. 2006. Darwin's dilemma: the realities of the Cambrian ‘explosion.’. Philosophical Transactions of the Royal Society of London B 361:1069–1083. CrossRef, PubMed
Corliss, J. O. 1990. Phylum Zoomastigina. Class Opalinata. Pp. 239–245 in Margulis et al. 1990.
Cruse, T. 1991. The sedimentology, depositional environment and Ediacaran fauna of the Stirling Range Formation, Western Australia. B.Sc. Honours thesis. University of Western Australia, Perth.
Cruse, T. and L. B. Harris. 1994. Ediacaran fossils from the Stirling Range Formation, Western Australia. Precambrian Research 67:(1–2). 1–10. CrossRef, CSA
Cruse, T., L. B. Harris, and B. Rasmussen. 1993. The discovery of Ediacaran trace and body fossils in the Stirling Range Formation, Western Australia: implications for sedimentation and deformation during the Pan-African orogenic cycle. Australian Journal of Earth Sciences 40:293–296. CrossRef, CSA
Curds, C. R., M. A. Gates, and D. M. Roberts. 1983. British and other freshwater ciliated Protozoa, Part 2. Ciliophora: Oligohymenophora and Polyhymenophora keys and notes for the identification of the free-living genera. Cambridge University Press, Cambridge.
Davies, M. S. and E. J. Cliffe. 2000. Adsorption of metals in seawater to limpet (Patella vulgata) pedal mucus. Bulletin of Environmental Contamination and Toxicology 64:228–264. CrossRef, PubMed, CSA
Davies, M. S. and S. J. Hawkins. 1998. Mucus from marine molluscs. Advances in Marine Biology 34:1–71. CrossRef
Douzery, E. J P., E. A. Snell, E. Bapteste, F. Delsuc, and H. Philippe. 2004. The timing of eukaryotic evolution: does a relaxed molecular clock reconcile proteins and fossils? Proceedings of the National Academy of Sciences USA 101:15386–15391. CrossRef, PubMed
Droser, M. L., S. Jensen, and J. G. Gehling. 2002. Trace fossils and substrates of the terminal Proterozoic-Cambrian transition: implications for the record of early bilaterians and sediment mixing. Proceedings of the National Academy of Sciences USA 99:12572–12576. CrossRef, PubMed, CSA
Du, R. and L. Tian. 1985. Discovery and preliminary study of mega-alga Longfengshania from the Qingbaikou System of the Yanshan Mountain area. Acta Geologica Sinica 1985:183–190.
Dupraz, C., P. T. Visscher, L. K. Baumgartner, and R. P. Reid. 2004. Microbe-mineral interactions: early carbonate precipitation in a hypersaline lake (Eleuthera Island, Bahamas). Sedimentology 51:745–765. CrossRef
Ehlers, U. and B. Sopott-Ehlers. 1997. Ultrastructure of the subepidermal musculature of Xenoturbella bocki, the adelphotaxon of the Bilateria. Zoomorphology 117:71–79. CrossRef
Gehling, J. G., G. M. Narbonne, and M. M. Anderson. 2000. The first named Ediacaran body fossil; Aspidella terranovica. Palaeontology 43:427–456. CrossRef
Gerdes, G., T. Klenke, and N. Noffke. 2000. Microbial signatures in peritidal siliciclastic sediments: a catalogue. Sedimentology 47:279–308. CrossRef
Glaessner, M. F. 1969. Trace fossils from the Precambrian and basal Cambrian. Lethaia 2:369–393. CrossRef
Gräf, W. and J. Schmitt. 1979. Wassermyxobakterien (Sporocytophaga cauliformis) und die Ordnung “Myxobacterales.”. Zentralblatt für Bakteriologie, Abteilung 1 169:240–252. PubMed
Graur, D. and W. Martin. 2004. Reading the entrails of chickens: molecular timescales of evolution and the illusion of precision. Trends in Genetics 20:80–86. CrossRef, PubMed
Han, T-M. and B. Runnegar. 1992. Megascopic eukaryotic algae from the 2.1 billion-year-old Negaunee Iron-Formation, Michigan. Science 257:232–235. CrossRef, PubMed, CSA
Harris, L. B. 1994. Neoproterozoic sinistral displacement along the Darling Mobile Belt, Western Australia, during Gondwanaland assembly. Journal of the Geological Society, London 151:901–904. CrossRef
Harris, L. B. and J. Beeson. 1993. Gondwanaland significance of Lower Palaeozoic deformation in central India and SW Western Australia. Journal of the Geological Society, London 150:811–814. CrossRef
Harris, L. B. and Z-X. Li. 1995. Palaeomagnetic dating and tectonic significance of dolerite intrusions in the Albany Mobile Belt, Western Australia. Earth and Planetary Science Letters 131:143–164. CrossRef
Hedges, S. B., H. Chen, S. Kumar, D. Y-C. Wang, A. S. Thompson, and H. Watanabe. 2001. A genomic timescale for the origin of eukaryotes. BMC Evolutionary Biology 1(4). [Published online 12 September 2001.].
Hoffman, P. F., A. J. Kaufman, G. P. Halverson, and D. P. Schrag. 1998. A Neoproterozoic Snowball Earth. Science 281:1342–1346. CrossRef, PubMed, CSA
Hofmann, H. J. 1985. Precambrian carbonaceous megafossils. Pp. 20–33 in D. F. Toomey and M. H. Nitecki, eds. Paleoalgology: contemporary research and applications. Springer, Berlin.
Hofmann, H. J. 1994. Proterozoic carbonaceous compression (“metaphytes” and “worms”). Pp. 342–357 in S. Bengtson, ed. Early life on Earth. Columbia University Press, New York.
Hofmann, H. J. and J. Chen. 1981. Carbonaceous megafossils from the Precambrian (1800 Ma) near Jixian, northern China. Canadian Journal of Earth Sciences 18:443–447.
Hofmann, H. J., E. W. Mountjoy, and M. W. Teitz. 1991. Ediacaran fossils and dubiofossils, Miette Group of Mount Fitzwilliam area, British Columbia. Canadian Journal of Earth Sciences 28:1541–1552. CSA
International Commission on Zoological Nomenclature. 1999. Code of zoological nomenclature, 4th ed. International Trust for Zoological Nomenclature, London.
Israelsson, O. 1997. [Xenoturbella's molluscan relatives] … and molluscan embryogenesis. Nature 390:32. CrossRef, CSA
Israelsson, O. 1999. New light on the enigmatic Xenoturbella (phylum uncertain): ontogeny and phylogeny. Proceedings of the Royal Society of London B 266:835–841. CrossRef
Jensen, S. 1997. Trace fossils from the Lower Cambrian Mickwitzia sandstone, south-central Sweden. Fossils and Strata 42:1–111.
Jensen, S. 2003. The Proterozoic and earliest Cambrian trace fossil record; patterns, problems and perspectives. Integrative and Comparative Biology 43:219–228. CrossRef
Jensen, S., M. L. Droser, and J. G. Gehling. 2005. Trace fossil preservation and the early evolution of animals. Palaeogeography, Palaeoclimatology, Palaeoecology 220:19–29. CrossRef
Kauffman, E. G. and J. R. Steidtmann. 1981. Are these the oldest metazoan trace fossils? Journal of Paleontology 55:923–947.
Kirschvink, J. L. 1992. Late Proterozoic low-latitude global glaciation: the Snowball Earth. Pp. 51–52 in J. W. Schopf and C. Klein, eds. The Proterozoic biosphere: a multidisciplinary study. Cambridge University Press, Cambridge.
Kirschvink, J. L., E. J. Gaidos, L. E. Bertani, N. J. Beukes, J. Gutzmer, L. N. Maepa, and R. E. Steinberger. 2000. Paleoproterozoic snowball Earth: extreme climatic and geochemical global change and its biological consequences. Proceedings of the National Academy of Sciences USA 97:1400–1405. CrossRef, PubMed, CSA
Kitazato, H. 1988. Locomotion of some benthic foraminifera in and on sediments. Journal of Foraminiferal Research 18:344–349.
Knoll, A. H. 1994. Proterozoic and Early Cambrian protists: evidence for accelerating evolutionary tempo. Proceedings of the National Academy of Sciences USA 91:6743–6750. CrossRef, PubMed, CSA
Książkiewicz, M. 1974. Trace fossils in the flysch of the Polish Carpathians. Palaeontologia Polonica 36:1–208.
Levin, L. 1994. Paleoecology and ecology of xenophyophores. Palaios 9:32–41. CrossRef
Lom, J. 1990. Phylum Myxozoa. Pp. 36–52 in Margulis et al. 1990.
Lucus, A. and L. C. Douglas. 1934. Principles underlying ciliary activity in the respiratory tract. Archives of Otolaryngology 20:518–541.
Lundin, K. 2000. Xenoturbella: a creature of contradiction. Fauna och Flora 95:44–48.
Marée, A. F M. and P. Hogeweg. 2001. How amoeboids self-organize into a fruiting body: multicellular coordination in Dictyostelium discoideum. Proceedings of the National Academy of Sciences USA 98:3879–3883. CrossRef, PubMed, CSA
Margulis, L., J. O. Corliss, M. Melkonian, and D. J. Chapman. eds. 1990. Handbook of Protoctista. Jones and Bartlett, Boston.
Martin, G. G. 1978. Ciliary gliding in lower invertebrates. Zoomorphologie 91:249–261. CrossRef
Muhling, P. C. and A. T. Brakel. 1985. Mount Barker–Albany 1:250000 geological series—Explanatory notes. Geological Society of Western Australia, Perth.
Norén, M. and U. Jondelius. 1997. Xenoturbella's molluscan relatives. Nature 390:31–32. CrossRef, CSA
Otsuka, J. and N. Sugaya. 2003. Advanced formulation of base pair changes in the stem regions of ribosomal RNAs; its application to mitochondrial rRNAs for resolving the phylogeny of animals. Journal of Theoretical Biology 222:447–460. PubMed, CSA
Palsson, E. and H. G. Othmer. 2000. A model for individual and collective cell movement in Dictyostelium discoideum. Proceedings of the National Academy of Sciences USA 97:10448–10453. CrossRef, PubMed, CSA
Pawlowski, J., M. Holzmann, C. Berney, J. Fahrni, A. J. Gooday, T. Cedhagen, A. Habura, and S. S. Bowser. 2003. The evolution of early Foraminifera. Proceedings of the National Academy of Sciences USA 100:11494–11498. CrossRef, PubMed, CSA
Pedersen, K. J. and L. R. Pedersen. 1986. Fine structural observations on the extracellular matrix (ECM) of Xenoturbella bocki Westblad, 1949. Acta Zoologica 72:181–201.
Peterson, K. J., J. B. Lyons, K. S. Nowak, C. M. Takacs, M. J. Wargo, and M. A. McPeek. 2004. Estimating metazoan divergence times with a molecular clock. Proceedings of the National Academy of Sciences USA 101:6536–6541. CrossRef, PubMed
Porter, S. and A. H. Knoll. 2000. Testate amoebae in the Neoproterozoic Era: evidence from vase-shaped microfossils in the Chuar Group, Grand Canyon. Paleobiology 26:360–385. Abstract, CSA
Raikova, O. I., M. Reuter, U. Jondelius, and M. K S. Gustafsson. 2000. An immunocytochemical and ultrastructural study of the nervous and muscular systems of Xenoturbella westbladi (Bilateria inc. sed). Zoomorphology 120:107–118. CrossRef, CSA
Rasmussen, B. and I. R. Fletcher. 2004. Zirconolite: a new U-Pb chronometer for mafic igneous rocks. Geology 32:785–788. CrossRef
Rasmussen, B., S. Bengtson, I. R. Fletcher, and N. McNaughton. 2002a. Discoidal impressions and trace-like fossils more than 1200 million years old. Science 296:1112–1115. CrossRef, PubMed, CSA
Rasmussen, B., S. Bengtson, I. R. Fletcher, and N. McNaughton. 2002b. Ancient animals or something else entirely? Response. Science 298:58–59.
Rasmussen, B., P. K. Bose, S. Sarkar, S. Banerjee, I. R. Fletcher, and N. J. McNaughton. 2002c. 1.6 Ga U-Pb zircon age for the Chorhat Sandstone, lower Vindhyan, India: Possible implications for early evolution of animals. Geology 30:103–106. CrossRef
Rasmussen, B., I. R. Fletcher, S. Bengtson, and N. McNaughton. 2004. SHRIMP U-Pb dating of diagenetic xenotime in the Stirling Range Formation, Western Australia: 1.8 billion year minimum age for the Stirling biota. Precambrian Research 133:329–337. CrossRef
Rauprich, O., M. Matsushita, C. J. Weijer, F. Siegert, S. E. Esipov, and J. A. Shapiro. 1996. Periodic phenomena in Proteus mirabilis swarm colony development. Journal of Bacteriology 178:6525–6538. PubMed, CSA
Ray, J. S., M. W. Martin, J. Veizer, and S. A. Bowring. 2002. U-Pb zircon dating and Sr isotope systematics of the Vindhyan Supergroup, India. Geology 30:131–134. CrossRef
Reisinger, E. 1960. Was ist Xenoturbella? Zeitschrift für wissenschaftliche Zoologie 164:188–198.
Riemann, F. and E. Helmke. 2002. Symbiotic relations of sediment-agglutinating nematodes and bacteria in detrital habitats: the enzyme-sharing concept. Marine Ecology 23:93–113. CrossRef, CSA
Rokas, A., D. Krüger, and S. B. Carroll. 2005. Animal evolution and the molecular signature of radiations compressed in time. Science 310:1933–1938. CrossRef, PubMed
Schieber, J. 1998. Possible indicators of microbial mat deposits in shales and sandstones: examples from the Mid-Proterozoic Belt Supergroup, Montana, U.S.A. Sedimentary Geology 120:105–124. CrossRef, CSA
Schieber, J. 2002. The role of an organic slime matrix in the formation of pyritized burrow trails and pyrite concretions. Palaios 17:104–109. CrossRef
Schneider, D. A., M. E. Bickford, W. F. Cannon, K. J. Schulz, and M. A. Hamilton. 2002. Age of volcanic rocks and syndepositional iron formations, Marquette Range Supergroup: implications for the tectonic setting of Paleoproterozoic iron formations of the Lake Superior region. Canadian Journal of Earth Sciences 39:999–1012. CrossRef
Schweitzer, C. E., R. M. Feldmann, S. Marenssi, and D. A. Waugh. 2005. Remarkably preserved annelid worms from the La Meseta Formation (Eocene), Seymour Island, Antarctica. Palaeontology 48:1–13. CrossRef
Seilacher, A., P. K. Bose, and F. Pflüger. 1998. Triploblastic animals more than 1 billion years ago: trace fossil evidence from India. Science 282:80–83. CrossRef, PubMed, CSA
Seilacher, A., D. Grazhdankin, and A. Legouta. 2003. Ediacaran biota: the dawn of animal life in the shadow of giant protists. Paleontological Research 7:43–54. CrossRef
Shapiro, J. A. and M. Dworkin. eds. 1997. Bacteria as multicellular organisms. Oxford University Press, Oxford.
Shen, Y., A. H. Knoll, and M. R. Walter. 2003. Evidence for low sulphate and anoxia in a mid-Proterozoic marine basin. Nature 423:632–635. CrossRef, PubMed, CSA
Shimkets, L. J. 1990. Social and developmental biology of myxobacteria. Microbiological Reviews 54:473–501. PubMed
Song, Y., R. G. Black, and J. H. Lipps. 1994. Morphological optimization in the largest living foraminifera: implications from finite element analysis. Paleobiology 20:14–26. CSA
Sun, W. 1986. Precambrian medusoids: the Cyclomedusa plexus and Cyclomedusa-like pseudofossils. Precambrian Research 31:325–360. CrossRef
Sun, W., G. Wang, and B. Zhou. 1986. Macroscopic worm-like body fossils from the Upper Precambrian (900–700 Ma), Huainan District, Anhui, China and their stratigraphic and evolutionary significance. Precambrian Research 31:377–403. CrossRef
Tendal, O. S. 1972. A monograph of the Xenophyophoria. Galathea Report 12:1–103.
Thomsen, E. and T. O. Vorren. 1984. Pyritization of tubes and burrows from Late Pleistocene continental shelf sediments off north Norway. Sedimentology 31:481–492. CrossRef, CSA
Turek, A. and N. C N. Stephenson. 1966. The radiometric age of the Albany granite and the Stirling Range Beds, southwest Australia. Journal of the Geological Society of Australia 13:449–456.
Walter, M. R. 1994. Stromatolites: the main geological source of information on the evolution of the early benthos. Pp. 270–286 in S. Bengtson, ed. Early life on Earth. Columbia University Press, New York.
Wang, D. Y C., S. Kumar, and S. B. Hedges. 1999. Divergence time estimates for the early history of animal phyla and the origin of plants, animals and fungi. Proceedings of the Royal Society of London B 266:163–171. CrossRef, PubMed, CSA
Wang, G. X. 1982. Late Precambrian Annelida and Pogonophora from the Huainan of Anhui Province. Tianjin Institute of Geology and Mineral Resources Bulletin 1982:69–22.
Westblad, E. 1950. Xenoturbella bocki n.g., n.sp., a peculiar, primitive Turbellarian type. Arkiv för Zoologi 1:311–29.
Wilkins, M. R. and K. L. Williams. 1995. The extracellular matrix of the Dictyostelium discoideum slug. Experientia Basel 51:1189–1196. CrossRef, PubMed
Woolnough, W. G. 1920. A geological reconnaissance of the Stirling Ranges of Western Australia. Journal and Proceedings of the Royal Society of New South Wales 54:79–112.
Wray, G. A., J. S. Levinton, and L. H. Shapiro. 1996. Molecular evidence for deep pre-Cambrian divergences among metazoan phyla. Science 274:568–573. CrossRef, CSA
Zhang, Z. 1988. Longfengshania Du emend.: an earliest record of bryophyte-like fossils. Acta Palaeontologica Sinica 27:416–426. [In Chinese with English abstract.].
Zhu, S. and H. Chen. 1995. Megascopic multicellular organisms from the 1700-million-year-old Tuanshanzi Formation in the Jixian area, North China. Science 270:620–622. CrossRef, CSA
Zhu, S., S. Sun, X. Huang, Y. He, G. Zhu, L. Sun, and K. Zhang. 2000. Discovery of carbonaceous compressions and their multicellular tissues from the Changzhougou Formation (1800 Ma) in the Yanshan Range, North China. Chinese Science Bulletin 45:841–847. CrossRef

Figure 1. Location of the Stirling Range Formation and sample sites (black triangles)

Figure 2. Sedimentary features in the section on the southwestern slope of Barnett Peak

Figure 3. Section with trace fossils (surface marked by white arrows below the 7 m level) on the south slope of Barnett Peak, possibly corresponding to between 47.35 and 60 m in the section on Figure 2

Figure 4. Field photographs from three different angles of surface with trace fossils (cf. Fig. 10), showing the three-dimensional relationship of the mud drape and channel fill to the surrounding strata

Figure 5. Sedimentological interpretation of the sequence shown in Figure 4. See text for details

Figure 6. Paleocurrent measurements from Barnett Peak

Figure 7. Reconstruction of sedimentary paleoenvironment based on analyses of paleocurrents and lithofacies in the Barnett Peak sections

Figure 8. Slab with Myxomitodes stirlingensis n. igen., n. isp., from the south slope of Barnett Peak. Holotype, UWA 114336a (left part, also figured as Fig. 2 A,C,G by Rasmussen et al. 2002a) and UWA 114336c (right part). Lower image shows drawings of ridges traced from photographs and specimens. See also Figures 12, 13A, and 14

Figure 9. Myxomitodes stirlingensis n. igen., n. isp., from the south slope of Barnett Peak. UWA 114336b, detail of specimen shown in Figure 8 (isolated trail between middle and left cluster of trails), sectioned. A, Specimen after sectioning. B, Polished sectioned surface (of lower half of A). Asterisks show corresponding positions in A and B

Figure 10. Field photographs of uncollected Myxomitodes stirlingensis n. igen., n. isp., at the base of a channel-fill sandstone, south slope of Barnett Peak. Lettering in A shows location of detailed photographs B–I. B1–I1 show drawings of ridges traced from photographs and latex casts. Scale in I1 is also for items B–H

Figure 11. Myxomitodes stirlingensis n. igen., n. isp., from the south slope of Barnett Peak. A, UWA 132251. B, UWA 132252

Figure 12. Myxomitodes stirlingensis n. igen., n. isp., from the south slope of Barnett Peak, UWA 114336c, detail of specimen in Figure 8 (middle part). Right-hand images shows drawings of ridges traced from photographs and specimen

Figure 13. Myxomitodes stirlingensis n. igen., n. isp., from the south slope of Barnett Peak. Stereo-pairs of regions discussed by Conway Morris (2002). A, UWA 114336a (cf. Rasmussen et al. 2002a: Fig. 2C and Fig. 8 herein). B, UWA 114336b (cf. Rasmussen et al. 2002a: Fig. 2E). See text for discussion

Figure 14. Myxomitodes stirlingensis n. igen., n. isp., from the south slope of Barnett Peak, showing crossing of paired ridges. A, Positive cast (silicon rubber, made from latex mold of original specimen) of uncollected specimen also figured in Figure 10G, lower right. Stereo-pair. B–D, UWA 114336c, detail of specimen in Figure 8, middle part. B, Stereo-pair. C, Interpretative drawing of ridges traced from photographs and specimen, implying crossing-over of mucus strings. D, Alternative interpretative drawing, implying juxtaposition of several short trails. See text for discussion

Figure 15. Recent gastropod trails. A, Lateral sediment ridges pushed up in thin layer of fine sand on top of hard rock surface in shallow water (tidal shore near Newcastle, New South Wales). B–D, Mucus-bound trails formed subaerially in wind-blown sand dunes (shore south of Hopetoun, Western Australia). Note evidence of displacement of mucus strands after formation, as well as the crossing of lateral ridges due to twisting of strands (particularly in C; cf. Figure 14)

Figure 16. Proposed model of formation of Myxomitodes trails. A, Organism with bulbous body shape begins to stretch out its body and glide along slime tract. B, The moving organism produces lateral ridges of sediment-entrained mucus; the flaring initial part of the trail reflects the thicker body of the organism before it starts to move. C, Organism makes a turn. D, Organism has left the trail

Figure 17. Proposed model of preservation of Myxomitodes trails. A, Organism moving along mucus strand pushes up muddy sediment and mucus into lateral ridges. B, Sediment-mucus strand remains after animal has left. C, Mucus strand hardens through early diagenetic mineralization. D, Rapid deposition of sand compresses mineralized mucus strand into mud substrate. E, Strand substance disintegrates, allowing sand to cast the depressions in the mud

Figure 18. Discoidal fossils on the upper surface of quartzite slabs from level 20.42 m in the Barnett Peak section (Fig. 2). A, B, UWA 114338 (also figured in Cruse and Harris 1994: Figs. 2a, 5, and in Cruse et al. 1993: Fig. 2a), classified as Cyclomedusa davidi by Cruse (1994). C–E, UWA 114341, specimen broken through middle. D shows a broken surface through the specimen perpendicular to bedding, and E a bedding-parallel section 4.5 mm below the specimen; note undisturbed lamination below specimen

Figure 19. Small discoidal fossils on inferred lower surfaces, all collected from float. A, B, Discoidal fossils on the rippled sole of quartzite slab found at Toolbrunup Peak and classified as ichnogenus Bergaueria by Cruse and Harris (1994; also figured in Cruse et al. 1993: Fig. 2b). UWA 114345. C, D, UWA 114347, from Mondurup Peak. E, F, UWA 132250, from Mt. Hassell. Frames indicate positions of blowups

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