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Ediacaran distributions in space and time: testing assemblage concepts of earliest macroscopic body fossils

Published online by Cambridge University Press:  25 May 2016

Thomas H. Boag ,
Simon A. F. Darroch  and
Marc Laflamme
Thomas H. Boag
Affiliation:
Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, Ontario, L5L 1C6, Canada. E-mail: [email protected], [email protected].
Simon A. F. Darroch
Affiliation:
Department of Earth and Environmental Sciences, Vanderbilt University, 5726 Stevenson Center, 7th Floor, Nashville, Tennessee, 37240, U.S.A. E-mail: [email protected]
Marc Laflamme
Affiliation:
Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, Ontario, L5L 1C6, Canada. E-mail: [email protected], [email protected].
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Abstract

The mid-late Ediacaran Period (~579–541 Ma) is characterized by globally distributed marine soft-bodied organisms of unclear phylogenetic affinities colloquially called the “Ediacara biota.” Despite an absence of systematic agreement, previous workers have tested for underlying factors that may control the occurrence of Ediacaran macrofossils in space and time. Three taxonomically distinct “assemblages,” termed the Avalon, White Sea, and Nama, were identified and informally incorporated into Ediacaran biostratigraphy. After ~15 years of new fossil discoveries and taxonomic revision, we retest the validity of these assemblages using a comprehensive database of Ediacaran macrofossil occurrences. Using multivariate analysis, we also test the degree to which taphonomy, time, and paleoenvironment explain the taxonomic composition of these assemblages. We find that: (1) the three assemblages remain distinct taxonomic groupings; (2) there is little support for a large-scale litho-taphonomic bias present in the Ediacaran; and (3) there is significant chronostratigraphic overlap between the taxonomically and geographically distinct Avalonian and White Sea assemblages ca. 560–557 Ma. Furthermore, both assemblages show narrow bathymetric ranges, reinforcing that they were paleoenvironmental–ecological biotopes and spatially restricted in marine settings. Meanwhile, the Nama assemblage appears to be a unique faunal stage, defined by a global loss of diversity, coincident with a noted expansion of bathymetrically unrestricted, long-ranging Ediacara taxa. These data reinforce that Ediacaran biodiversity and stratigraphic ranges of its representative taxa must first statistically account for varying likelihood of preservation at a local scale to ultimately aggregate the Ediacaran macrofossil record into a global biostratigraphic context.

Type
Articles
Information
Paleobiology , Volume 42 , Issue 4 , November 2016 , pp. 574 - 594
Copyright
Copyright © 2016 The Paleontological Society. All rights reserved 

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References

Literature Cited

Amthor, J. E., Grotzinger, J. P., Schröder, S., Bowring, S. A., Ramezani, J., Martin, M. W., and Matter, A.. 2003. Extinction of Cloudina and Namacalathus at the Precambrian–Cambrian boundary in Oman. Geology 31(5):431–434.Google Scholar
Babcock, L. E., Grunow, A. M., Sadowski, G. R., and Leslie, S. A.. 2005. Corumbella, an Ediacaran-grade organism from the Late Neoproterozoic of Brazil. Palaeogeography, Palaeoclimatology, Palaeoecology 220:7–18.CrossRefGoogle Scholar
Baselga, A. 2010. Partitioning the turnover and nestedness components of beta diversity. Global Ecology and Biogeography 19:134–143.CrossRefGoogle Scholar
Baselga, A., and Orme, D. L.. 2012. Betapart: an R package for the study of beta diversity. Methods in Ecology and Evolution 3:808–812.Google Scholar
Bengston, S. M., and Zhao, Y.. 1992. Predatorial borings in late Precambrian mineralized exoskeletons. Science 257:367–369.Google Scholar
Benus, A. P. 1988. Sedimentological context of a deep-water Ediacaran fauna (Mistaken Point, Avalon Zone, eastern Newfoundland). In E. Landing, G. M. Narbonne, and P. M. Myrow eds. Trace fossils, small shelly fossils and the Precambrian–Cambrian boundary. New York State Museum and Geophysical Survey Bulletin 463:8–9.Google Scholar
Billings, E. 1872. Fossils in Huronian rocks. Canadian Naturalist and Quarterly Journal of Science 6:478.Google Scholar
Bosak, T., Lahr, D. J. G., Pruss, S. B., Macdonald, F. A., Gooday, A. J., Dalton, L., and Matys, E. D.. 2012. Possible early Foraminiferans in post-Sturtian (716–635 Ma) cap carbonates. Geology 40(1):67–70.Google Scholar
Bouougri, E. H., and Porada, H.. 2007. Siliciclastic biolaminites indicative of widespread microbial mats in the Neoproterozoic Nama Group of Namibia. Journal of African Earth Sciences 48:38–48.CrossRefGoogle Scholar
Bouougri, E. H., Porada, H., Weber, K., and Reitner, J.. 2011. Sedimentology and palaeoecology of Ernietta-bearing Ediacaran deposits in southern Namibia: implications for infaunal vendobiont communities. Advances in Stromatolite Geobiology: Lecture Notes in Earth Sciences 313:473–506.CrossRefGoogle Scholar
Bowring, S. A., Grotzinger, J. P., Isachsen, C. E., Knoll, A. H., Pelechaty, S., and Kolosov, P.. 1993. Calibrating rates of early Cambrian evolution. Science 261:1293–1298.Google Scholar
Boynton, H. E., and Ford, T. D.. 1979. Pseudovendia charnwoodensis—a new Precambrian arthropod from Charnwood Forest, Leicestershire. Mercian Geologist 7:175–177.Google Scholar
Boynton, H. E., and Ford, T. D.. 1995. Ediacaran fossils from the Precambrian (Charnian Supergroup) of Charnwood Forest, Leicestershire, England. Mercian Geologist 13:165–182.Google Scholar
Boynton, H. E., and Ford, T. D.. 1996. Ediacaran fossils from the Precambrian (Charnian Supergroup) of Charnwood Forest, Leicestershire, England—revision of nomenclature. Mercian Geologist 14:3.Google Scholar
Brasier, M. D., Shields, G., Kuleshov, V. N., and Zhegallo, E. A.. 1996. Integrated chemo- and biostratigraphic calibration of early animal evolution: Neoproterozoic–early Cambrian of southwest Mongolia. Geological Magazine 133(4):445–485.Google Scholar
Brasier, M. D., Antcliffe, J. B., and Callow, R. H. T.. 2010. Evolutionary trends in remarkable fossil preservation across the Ediacaran–Cambrian transition and the impact of metazoan mixing. In P. A. Allison and D. J. Bottjer, eds. Taphonomy: process and bias through time. Aims and Scope Topics in Geobiology 32:519–567.CrossRefGoogle Scholar
Brasier, M. D., Antcliffe, J. B., and Liu, A. G.. 2012. The architecture of Ediacaran fronds. Palaeontology 55:1105–1124.Google Scholar
Briggs, D. E. G. 2003. The role of decay and mineralization in the preservation of soft bodied fossils. Annual Review of Earth and Planetary Sciences 31:275–301.Google Scholar
Budd, G. E., and Jensen, S.. 2015. The origin of the animals and a “Savannah” hypothesis for early bilaterian evolution. Biological Reviews. doi: 10.1111/brv.12239.Google Scholar
Burzynski, G., and Narbonne, G. M.. 2015. The discs of Avalon: relating discoid fossils to frondose organisms in the Ediacaran of Newfoundland, Canada. Palaeogeography, Palaeoclimatology, Palaeoecology 434:34–45.Google Scholar
Cai, Y., Schiffbauer, J. D., Hua, H., and Xiao, S.. 2012. Preservational modes in the Ediacaran Gaojiashan Lagerstätte: pyritization, aluminosilicification, and carboniferous compression. Palaeogeography, Palaeoclimatology, Palaeocology 326–328:109–117.Google Scholar
Callow, R. H. T., and Brasier, M. D.. 2009. Remarkable preservation of microbial mats in Neoproterozoic siliciclastic settings: implications for Ediacaran taphonomic models. Earth-Science Reviews 96:207–219.Google Scholar
Carbone, C., and Narbonne, G. M.. 2014. When life got smart: the evolution of behavioral complexity through the Ediacaran and early Cambrian of NW Canada. Journal of Paleontology 88(2):309–330.CrossRefGoogle Scholar
Carbone, C. A., Narbonne, G. M., Macdonald, F. A., and Boag, T. H.. 2015. New Ediacaran fossils from the uppermost Blueflower Formation, northwest Canada: disentangling biostratigraphy and paleoecology. Journal of Paleontology 89:281–291.Google Scholar
Chen, M. E., Chen, X. G., and Lao, Q. Y.. 1975. An introduction to the metazoa fossil from the upper Sinian System in southern Shensi and its stratigraphic significance. Sientia Geologica Sinica 2:181–192.Google Scholar
Chen, Z., Sun, W., and Hua, H.. 2002. Preservation and morphological interpretation of late Sinian Gaojiashania from southern Shaanxi. Acta Palaeontologica Sinica 41:448–454.Google Scholar
Chen, Z., Zhou, C., Xiao, S., Wang, W., Guan, C., Hua, H., and Yuan, X.. 2014. New Ediacaran fossils preserved in marine limestone and their ecological implications. Scientific Reports 4:4180.Google Scholar
Clapham, M. E. 2011. Ordination methods and the evaluation of Ediacaran communities. In M. Laflamme, J. D. Schiffbauer, and S. Q. Dornbos, eds. Quantifying the evolution of early life. Topics in Geobiology 36:3–21.Google Scholar
Clapham, M. E., Narbonne, G. M., and Gehling, J. G.. 2003. Paleoecology of the oldest known animal communities: Ediacaran assemblages at Mistaken Point, Newfoundland. Paleobiology 29:527–544.Google Scholar
Clarke, K. R. 1993. Non-parametric multivariate analyses of changes in community structure. Australian Journal of Ecology. 18:117–143.Google Scholar
Condon, D., Zhu, M., Bowring, S. A., Wang, S., Yang, A., and Jin, Y.. 2005. U-Pb ages from the Neoproterozoic Doushantuo Formation, China. Science 308:95–98.CrossRefGoogle ScholarPubMed
Crimes, T. P., and McIlroy, D.. 1999. A biota of Ediacaran aspect from lower Cambrian strata on the Digermul Peninsula, Arctic Norway. Geological Magazine 136:633–642.CrossRefGoogle Scholar
Darroch, S. A. F., and Wagner, P.. 2015. Response of beta diversity to pulses of Ordovician–Silurian mass extinction. Ecology 96:532–549.CrossRefGoogle ScholarPubMed
Darroch, S. A. F., Laflamme, M., Schiffbauer, J. D., and Briggs, D. E. G.. 2012. Experimental formation of a microbial death mask. Palaios 27:293–303.CrossRefGoogle Scholar
Darroch, S. A. F., Laflamme, M., and Clapham, M. E.. 2013. Population structure of the oldest known macroscopic communities from Mistaken Point, Newfoundland. Paleobiology 39:591–608.Google Scholar
Darroch, S. A. F., Sperling, E. A., Boag, T. H., Racicot, R. A., Mason, S. J., Morgan, A. S., Tweedt, S., Myrow, P., Johnston, D. T., Erwin, D. H., and Laflamme, M.. 2015. Biotic replacement and mass extinction of the Ediacara biota. Proceedings of the Royal Society of London B 282:20151003.Google ScholarPubMed
Davies, N. S., Liu, A. G., Gibling, M. R., and Miller, R. F.. 2016. Resolving MISS conceptions and misconceptions: a geological approach to sedimentary surface textures generated by microbial and abiotic processes. Earth-Science Reviews 154:210–246.Google Scholar
Erwin, D. H., Laflamme, M., Tweedt, S. M., Sperling, E. A., Pisani, D., and Peterson, K. J.. 2011. The Cambrian conundrum: early divergence and later ecological success in the early history of animals. Science 334:1091–1097.CrossRefGoogle ScholarPubMed
Fedonkin, M. A., Gehling, J. G., Grey, K., Narbonne, G. M., and Vickers-Rich, P.. 2007a. The rise of animals: evolution and diversification of the Kingdom Animalia. John Hopkins University Press, Baltimore, Md.Google Scholar
Fedonkin, M. A., Simonetta, A., and Ivantsov, A. Y.. 2007b. New data on Kimberella, the Vendian mollusc-like organism (White Sea region, Russia): palaeocecological and evolutionary implications. Geological Society of London Special Publication 286:157–179.CrossRefGoogle Scholar
Ford, T. D. 1958. Precambrian fossils from Charnwood Forest. Yorkshire Geological Society Proceedings 31:211–217.Google Scholar
Gehling, J. G. 1988. A cnidarian of actinian-grade from the Ediacaran Pound Subgroup, South Australia. Alcheringa 12:299–314.Google Scholar
Gehling, J. G. 1991. The case for Ediacaran fossil roots to the metazoan tree. Geological Society of India Memoir 20:181–224.Google Scholar
Gehling, J. G. 1999. Microbial mats in terminal Proterozoic siliciclastics: Ediacaran death masks. Palaios 14:40–57.Google Scholar
Gehling, J. G., and Droser, M. L.. 2013. How well do fossil assemblages of the Ediacara biota tell time? Geology 41:447–450.Google Scholar
Gehling, J. G., Narbonne, G. M., and Anderson, M. M.. 2000. The first named Ediacaran body fossil, Aspidella terranovica . Palaeontology 43:427–456.Google Scholar
Gehling, J. G., Droser, M. L., Jensen, S. R., and Runnegar, B. N.. 2005. Ediacaran organisms: relating form and function. Pp. 43–67 in D. E. G. Briggs, ed. Evolving form and function: fossils and development. Proceedings of a symposium honoring Adolf Seilacher for his contributions to paleontology, in celebration of his 80th birthday. Peabody Museum of Natural History, Yale University, New Haven, Conn.Google Scholar
Germs, G. J. 1968. Discovery of a new fossil in the Nama system, South West Africa. Nature 219:53–54.Google Scholar
Germs, G. J. 1973. A reinterpretation of Rangea schneiderhoehni and the discovery of a related new fossil from the Nama Group, South West Africa. Lethaia 6:1–9.Google Scholar
Glaessner, M. F. 1958. New fossils from the base of the Cambrian in south Australia. Transactions of the Royal Society of South Australia 81:185–188.Google Scholar
Glaessner, M. F. 1984. The dawn of animal life: a biohistorical study. Cambridge University Press, Cambridge.Google Scholar
Grant, S. W. F. 1990. Shell structure and distribution of Cloudina, a potential index fossil for the terminal Proterozoic. American Journal of Science 290–A:261–294.Google Scholar
Grazhdankin, D. V. 2004. Patterns of distribution in the Ediacaran biotas: facies versus biogeography and evolution. Paleobiology 30:203–221.Google Scholar
Grazhdankin, D. V. 2014. Patterns of evolution of the Ediacaran soft-bodied biota. Journal of Paleontology 88:269–283.CrossRefGoogle Scholar
Grazhdankin, D. V., Balthasar, U., Nagovitsin, K. E., and Kochnev, B. B.. 2008. Carbonate-hosted Avalon-type fossils in arctic Siberia. Geology 36:803–806.CrossRefGoogle Scholar
Grotzinger, J. P., Watters, W. A., and Knoll, A. H.. 2000. Calcified metazoans in thrombolite–stromatolite reefs of the terminal Proterozoic Nama Group, Namibia. Paleobiology 26:334–359.Google Scholar
Gürich, G. 1930. Die bislang ältesten Spuren von Organismen in Südafrika. International Geological Congress. South Africa, 1929 (XV), Pretoria, Union of South Africa. Die altesten Fossilien Sud-Afrikas 2:670–680.Google Scholar
Gürich, G. 1933. Die Kuibis-Fossilien der Nama-Formation von Sudwest-afrika. Palaeontologische Zeitschrift 15:137–154.Google Scholar
Hagadorn, J. W., and Waggoner, B. M.. 2000. Ediacaran fossils from the Southwestern Great Basin, United States. Journal of Paleontology 74:349–359.2.0.CO;2>CrossRefGoogle Scholar
Hagadorn, J. W., Fedo, C. M., and Waggoner, B. M.. 2000. Early Cambrian Ediacaran-type fossils from California. Journal of Paleontology 74:731–740.Google Scholar
Hahn, G., Hahn, R., Leonardos, O. H., Pflug, H. D., and Walde, D. H. G.. 1982. Korperlich erhaltene Scyphozoen-Reste aus dem Jungprakambrium Brasiliens. Geologica et Palaeontologica 74:349–359.Google Scholar
Hall, C. M. S, Droser, M. L., Gehling, J. G., and Dzaugis, M. E.. 2015. Paleoecology of the enigmatic Tribrachidium: new data from the Ediacaran of South Australia. Precambrian Research 269:183–194.Google Scholar
Hammer, O., and Harper, D.. 2006. Paleontological data analysis. Blackwell, Oxford.Google Scholar
Hofmann, H. J., and Mountjoy, E. W.. 2001. Namacalathus–Cloudina assemblage in Neoproterozoic Miette Group (Byng Formation), British Columbia: Canada’s oldest shelly fossils. Geology 29:1091–1094.Google Scholar
Hofmann, H. J., Mountjoy, E. W., and Teitz, M. W.. 1991. Ediacaran fossils and dubiofossils, Miette Group of Mount Fitzwilliam area, British Columbia. Canadian Journal of Earth Sciences 28:1541–1552.Google Scholar
Hofmann, H. J., O’Brien, S. J., and King, A. F.. 2008. Ediacaran biota on Bonavista Peninsula, Newfoundland, Canada. Journal of Paleontology 82:1–36.Google Scholar
Holland, S. M. 1995. The stratigraphic distribution of fossils. Paleobiology 21:92–109.Google Scholar
Holland, S. M. 2003. Limits on fossil ranges that account for facies changes. Paleobiology 29:468–479.2.0.CO;2>CrossRefGoogle Scholar
Hua, H., Pratt, B. R., and Zhang, L. Y.. 2003. Borings in Cloudina shells: complex predator–prey dynamics in the terminal Neoproterozoic. Palaios 18:454–459.Google Scholar
Ivantsov, A. Y., and Fedonkin, M. A.. 2002. Conularid-like fossil from the Vendian of Russia: a metazoan clade across the Proterozoic/Palaeozoic boundary. Palaeontology 45:1219–1229.Google Scholar
Ivantsov, A. Y., Narbonne, G. M., Trusler, P. W., Greentree, C., and Vickers-Rich, P.. 2015. Elucidating Ernietta: new insights from exceptional specimens in the Ediacara of Namibia. Lethaia doi: 10.1111/let.12164.Google Scholar
Jensen, S., Gehling, J. G., and Droser, M. L.. 1998. Ediacara-type fossils in Cambrian sediments. Nature 393:567–569.Google Scholar
Kenchington, C. G., and Wilby, P. R.. 2014. Of time and taphonomy: preservation in the Ediacaran. In M. Laflamme, J. D. Schiffbauer, and S. A. F. Darroch, eds. Reading and Writing of the Fossil Record: Preservational Pathways to Exceptional Fossilization. Paleontological Society Papers. Paleontological Society Short Course 20:101–122.Google Scholar
Kidwell, S. M., and Holland, S. M.. 2002. The quality of the fossil record: implications for evolutionary analyses. Annual Review of Ecology, Evolution, and Systematics 33:561–588.Google Scholar
Knoll, A. H., Grotzinger, J. P., Kaufman, A. J., and Kolosov, P.. 1995. Integrated approaches to terminal Proterozoic stratigraphy: an example from the Olenek Uplift, northeastern Siberia. Precambrian Research 73:251–270.Google Scholar
Koleff, P., Gaston, K. J., and Lennon, J. J.. 2003. Measuring beta diversity for presence-absence data. Journal of Animal Ecology 72:367–382.Google Scholar
Laflamme, M., Narbonne, G. M., and Anderson, M. M.. 2004. Morphometric analysis of the Ediacaran frond Charniodiscus from the Mistaken Point Formation, Newfoundland. Journal of Paleontology 78:827–837.2.0.CO;2>CrossRefGoogle Scholar
Laflamme, M., Narbonne, G. M., Greentree, C., and Anderson, M. M.. 2007. Morphology and taphonomy of an Ediacaran frond: charnia from the Avalon Peninsula of Newfoundland. Geological Society of London Special Publication 286:237–257.Google Scholar
Laflamme, M., Schiffbauer, J. D., and Narbonne, G. M.. 2011a. Deep-water Microbially Induced Sedimentary Structures (MISS) in deep time: the Ediacaran fossil Ivesheadia. In N. K. Noffke and H. Chafetz, eds. Microbial mats in siliciclastic depositional systems through time. SEPM Special Publication 101:111–123.Google Scholar
Laflamme, M., Schiffbauer, J. D., Narbonne, G. M., and Briggs, D. E. G.. 2011b. Microbial biofilms and the preservation of the Ediacara biota. Lethaia 44:203–213.Google Scholar
Laflamme, M., Darroch, S. A. F., Tweedt, S. M., Peterson, K. J., and Erwin, D. H.. 2013. The end Ediacara biota: extinction, biotic replacement, or Cheshire Cat? Gondwana Research 23:558–573.CrossRefGoogle Scholar
Liu, A. G, McIlroy, D., and Brasier, M. D.. 2010. First evidence for locomotion in the Ediacara biota from the 565 Ma Mistaken Point Formation, Newfoundland. Geology 38:123–126.Google Scholar
Liu, A. G., McIlroy, D., Antcliffe, J. B., and Brasier, M. D.. 2011. Effaced preservation in the Ediacara biota and its implications for the early macrofossil record. Palaeontology 54:607–630.Google Scholar
Liu, A. G., McIlroy, D., Matthews, J. J., and Brasier, M. D.. 2013. Exploring an Ediacaran “nursery”: growth, ecology and evolution in rangeomorph palaeocommunity. Geology Today 38:123–126.Google Scholar
Liu, A. G., Matthews, J. J., Menon, L. R., McIlroy, D., and Brasier, M. D.. 2014. Haootia quadriformis n. sp., interpreted as a muscular cnidarian impression from the Late Ediacaran Period (approx. 560 Ma). Proceedings of the Royal Society of London B 281:20141202.Google Scholar
Liu, A. G., Kenchington, C. G., and Mitchell, E. G.. 2015. Remarkable insights into the paleoecology of the Avalonian Ediacaran macrobiota. Gondwana Research 27:1355–1380.Google Scholar
Lyons, T. W., Reinhard, C. T., and Planavsky, N. J.. 2014. The rise of oxygen in Earth’s early ocean and atmosphere. Nature 506:307–315.CrossRefGoogle ScholarPubMed
Maloof, A. C., Porter, S. M., Moore, J. L., Dudás, F. O., Bowring, S. A., Higgins, J. A., Fike, D. A., and Eddy, M. P.. 2010. The earliest Cambrian record of animals and ocean geochemical change. Geological Society of America Bulletin 122(11/12):1731–1774.Google Scholar
Mángano, M. G., and Buatois, L. A.. 2014. Decoupling of body-plan diversification and ecological structuring during the Ediacaran-Cambrian transition: evolutionary and geobiological feedbacks. Proceedings of the Royal Society of London B 281:20140038.Google Scholar
Martin, M. W., Grazhdankin, D. V., Bowring, S. A., Evans, D. A. D, Fedonkin, M. A., and Kirschvink, J. L.. 2000. Age of Neoproterozoic bilaterian body and trace fossils, White Sea, Russia: implications for Metazoan evolution. Science 288:841–845.Google Scholar
McIlroy, D., Brasier, M. D., and Moseley, J. B.. 1998. The Proterozoic–Cambrian transition within the “Charnian Supergroup” of central England and the antiquity of the Ediacara fauna. Journal of the Geological Society 155:401–411.Google Scholar
Narbonne, G. M. 2005. The Ediacara biota: Neoproterozoic origin of animals and their ecosystems. Annual Reviews of Earth and Planetary Sciences 33:13.1–13.22.CrossRefGoogle Scholar
Narbonne, G. M., Saylor, B. Z., and Grotzinger, J. P.. 1997. The youngest Ediacaran fossils from Southern Africa. Journal of Paleontology 71:953–967.Google Scholar
Narbonne, G. M., Laflamme, M., Greentree, C., and Trusler, P.. 2009. Reconstructing a lost world: Ediacaran rangeomorphs from Spaniard’s Bay, Newfoundland. Journal of Paleontology 83:503–523.Google Scholar
Narbonne, G. M., Xiao, S., and Shields, G.. 2012. Ediacaran period. Pp. 413–445 in F. Gradstein, J. Ogg, M. D. Schmidt, and G. Ogg, eds., Geologic Timescale 2012. Elsevier, New York. doi:10.1016/B978-0-444-59425-9.00018-4.Google Scholar
Narbonne, G. M., Laflamme, M., Trusler, P. W., Dalrymple, R. W., and Greentree, C.. 2014. Deep-water Ediacaran fossils from Northwestern Canada: taphonomy, ecology, and evolution. Journal of Paleontology 88:207–223.Google Scholar
Noble, S. R., Condon, D. J., Carney, J. N., Wilby, P. R., Pharaoh, T. C., and Ford, T. D.. 2014. U-Pb geochronology and global context of the Charnian Supergroup, UK: constraints on the age of key Ediacaran fossil assemblages. Geological Society of America Bulletin 127(1–2), 250–265.CrossRefGoogle Scholar
O’Brien, S. J., and King, A. F.. 2005. Late Neoproterozoic (Ediacaran) stratigraphy of Avalon zone sedimentary rocks, Bonavista Peninsula, Newfoundland. Newfoundland and Labrador Department of Natural Resources Geological Survey Report 5:101–113.Google Scholar
Oksanen, J. F., Blanchet, G., Kindt, R., Legendre, P., Minchin, P. R., O’Hara, R. B., Simpson, G. L., Solymos, P., Henry, M., Stevens, H., and Wagner, H.. 2015. Vegan: Community Ecology Package. R package version 2.0-10. http://CRAN.R-project.org/package=vegan.Google Scholar
Orr, P. J. 2014. Late Proterozoic–Early Phanerozoic “taphonomic windows”: the environmental and temporal distribution of recurrent modes of exceptional preservation. In M. Laflamme, J. D. Schiffbauer, and S. A. F. Darroch. Reading and Writing of the Fossil Record: Preservational Pathways to Exceptional Fossilization. Paleontological Society Papers. Paleontological Society Short Course 20.Google Scholar
Palij, V. M. 1976. Remains of soft-bodied animals and trace fossils from Upper Precambrian and Lower Cambrian of Podolia. Pp. 63–77 in V. A. Ryabenko, ed. Palaeontology and stratigraphy of the Upper Precambrian and Lower Paleozoic of the southwestern part of the East European Platform. Naukova Dumka, Kiev.Google Scholar
Peterson, K. J., and Butterfield, N. J.. 2005. Origin of the Eumetazoa: testing ecological predictions of molecular clocks against the Proterozoic fossil record. Proceedings of the National Academy of Sciences USA 102:9547–9552.CrossRefGoogle ScholarPubMed
Peterson, K. J., Lyons, J. B., Nowak, K. S., Takacs, C. M., Wargo, M. J., and McPeek, M. A.. 2004. Estimating metazoan divergence times with a molecular clock. Proceedings of the National Academy of Sciences USA 101:6536–6541.Google Scholar
Peterson, K. J., Cotton, J. A., Gehling, J. G., and Pisani, D.. 2008. The Ediacaran emergence of bilaterians: congruence between genetic and the geological fossil records. Philosophical Transactions of the Royal Society B 363:1435–1443.Google Scholar
Pflug, H. D. 1972. Zur fauna der Nama-Schichten in Sudwest Afrika. I. Pteridinia, Bau und systematische Zugehorikeit. Palaeontographica Abteilung A 143:226–262.Google Scholar
Preiss, W. V. 2000. The Adelaide Geosyncline of South Australia and its significance in Neoproterozoic continental reconstruction. Precambrian Research 100:21–63.Google Scholar
R Core Team 2015. R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org.Google Scholar
Rahman, I. A., Darroch, S. A. F., Racicot, R. A., and Laflamme, M.. 2015. Suspension feeding in the enigmatic Ediacaran organism Tribrachidium demonstrates complexity of Neoproterozoic ecosystems. Science Advances. doi: 10.1126/sciadv.1500800.CrossRefGoogle ScholarPubMed
Riedman, L. A., Porter, S. M., Halverson, G. P., Hurtgen, M. T., and Junium, C. K.. 2014. Organic-walled microfossil assemblages from glacial and interglacial Neoproterozoic units of Australia and Svalbard. Geology 42:1011–1014.Google Scholar
Schiffbauer, J. D., Xiao, S., Cai, Y., Wallace, A. F., Hua, H., Hunter, J. L., Xu, H., Peng, Y., and Kaufman, A. J.. 2014. A unifying model for Neoproterozoic–Paleozoic exceptional fossil preservation through pyritization and carbonaceous compression. Nature Communications 5:5754.Google Scholar
Schmitz, M. D. 2012. Appendix 2: radiometric ages used in GTS2012. Pp. 1045–1082 in F. Gradstein, J. Ogg, M. D. Schmitz, and G. Ogg, eds., The Geologic Time Scale 2012. Elsevier, Boston. doi:10.1016/B978-0-444-59425-9.15002-4.Google Scholar
Seilacher, A. D. 1992. Vendobionta and Psammocorallia—lost constructions of Precambrian evolution. Journal of the Geological Society, London 149:607–613.CrossRefGoogle Scholar
Seilacher, A., Grazhdankin, D. V., and Legouta, A.. 2003. Ediacara biota: The dawn of animal life in the shadow of giant protist. Paleontological Research 7:43–54.Google Scholar
Shanker, R., and Mathur, V. K.. 1992. Precambrian–Cambrian sequence in Krol Belt and Ediacaran fossils. Geophytology 22:25–36.Google Scholar
Shen, B., Dong, L., Xiao, S., and Kowalewski, M.. 2008. The Avalon explosion: evolution of Ediacara morphospace. Science 319:81–84.Google Scholar
Sokolov, B. S., and Fedonkin, M. A.. 1990. The Vendian System. Regional Geology. Springer-Verlag, Berlin. 2:38–75.Google Scholar
Sperling, E. A., Frieder, C. A., Raman, A. V., Girguis, P. R., Levin, L. A., and Knoll, A. H.. 2013. Oxygen, ecology, and the Cambrian explosion of animals. Proceedings of the National Academy of Sciences USA 110:13446–13451.Google Scholar
Sperling, E. A., Carbone, C., Strauss, J. V., Johnston, D. T., Narbonne, G. M., and Macdonald, F. A.. 2015. Oxygen, facies, and secular controls on the appearance of Cryogenian and Ediacaran body and trace fossils in the Mackenzie Mountains of northwestern Canada. Geological Society of America Bulletin. doi: 10.1130/B31329.1.Google Scholar
Stanley, S. M. 1976. Ideas on the timing of Metazoan diversification. Paleobiology 2:209–219.Google Scholar
Steiner, M., and Reitner, J.. 2001. Evidence of organic structures in Ediacara-type fossils and associated microbial mats. Geology 29:1119–1122.Google Scholar
Tarhan, L. G., Droser, M. L., and Gehling, J. G.. 2010. Taphonomic controls on Ediacaran diversity: uncovering the holdfast origin of morphologically variable enigmatic structures. Palaios 25:823–830.Google Scholar
Tarhan, L. G., Droser, M. L., Gehling, J. G., and Dzaugis, M. P.. 2015. Taphonomy and morphology of the Ediacaran form genus Aspidella . Precambrian Research 257:124–136.Google Scholar
Van Kranendonk, M. J., Gehling, J. G., and Shields, G. A.. 2008. Precambrian. Pp. 23–36 in J. G. Ogg, G. Ogg, and F. M. Gradstein, eds., The Concise Geologic Time Scale. Cambridge University Press, Cambridge.Google Scholar
Vickers-Rich, P., Ivantsov, A. Y., Trusler, P. W., Narbonne, G. M., Hall, M., Wilson, S., Greentree, C., Fedonkin, M. A., Elliot, D. A., Hoffmann, K., and Schneider, G. I. C. 2013. Reconstructing Rangea: new discoveries from the Ediacaran of southern Namibia. Journal of Paleontology 87:1–15.Google Scholar
Wade, M. 1972. Hydrozoa and Scyphozoa and other medusoids from the Precambrian Ediacara fauna, south Australia. Palaeontology 15:197–225.Google Scholar
Waggoner, B. M. 1999. Biogeographic analyses of the Ediacara biota: a conflict with paleotectonic reconstructions. Paleobiology 25:440–458.Google Scholar
Waggoner, B. M. 2003. The Ediacaran biotas in space and time. Integrated Comparative Biology 43:104–113.Google Scholar
Warren, L. V., Fairchild, T. R., Gaucher, C., Boggianai, P. C., Poiré, D. G., Anelli, L. E., and Inchausti, J. C. G.. 2011. Corumbella and in situ Cloudina in association with thrombolites in the Ediacaran Itapucumi Group, Paraguay. Terra Nova 23:383–389.Google Scholar
Weaver, P. G., McMenamin, M. A. S., and Tacker, R. C.. 2006. Paleoenvironmental and paleobiogeographic implications of a new Ediacaran body fossil from the Neoproterozoic Carolina Terrane, Stanly County, North Carolina. Precambrian Research 150:123–135.CrossRefGoogle Scholar
Wilby, P. R., Carney, J. N., and Howe, M. P. A.. 2011. A rich Ediacaran assemblage from eastern Avalonia: evidence of early widespread diversity in the deep ocean. Geology 39:655–658.Google Scholar
Williams, H., and King, A. F.. 1979. Trepassey map area, Newfoundland. Geological Survey of Canada Memoir 389:1–24.Google Scholar
Wood, D. A., Dalrymple, R. W., Narbonne, G. M., Gehling, J. G., and Clapham, M. E.. 2003. Paleoenvironmental analysis of the late Neoproterozoic Mistaken Point and Trepassey formations, southeastern Newfoundland. Canadian Journal of Earth Sciences 40:1375–1391.Google Scholar
Wood, R. A., Grotzinger, J. P., and Dickson, J. A. D.. 2002. Proterozoic modular biomineralized metazoan from the Nama Group, Namibia. Science 296:2383–2385.Google Scholar
Xiao, S., and Laflamme, M.. 2009. On the eve of animal radiation: phylogeny, ecology, and evolution of the Ediacara biota. Trends in Ecology and Evolution 24:31–40.Google Scholar
Xiao, S., Yuan, X., Steiner, M., and Knoll, A. H.. 2002. Macroscopic carbonaceous compressions in a terminal Proterozoic shale: a systematic reassessment of the Miaohe biota, South China. Journal of Paleontology 76:347–376.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 10:1–262.Google Scholar
Zakrevskaya, M. 2014. Paleoecological reconstruction of the Ediacaran benthic macroscopic communities of the White Sea (Russia). Palaeogeography, Palaeoclimatology, Palaeoecology 410:27–38.Google Scholar
Zhao, Y., Chen, M., Peng, J., Yu, M., He, M., Wang, Y., Yang, R., Wang, P., and Zhang, Z.. 2004. Discovery of a Miaohe-type biota from the Neoproterozoic Doushantuo Formation in Jiangkou County, Guizhou Province, China. Chinese Science Bulletin 49:2224–2226.Google Scholar
Zhu, M., Gehling, J. G., Xiao, S., Zhao, Y., and Droser, M. L.. 2008. Eight-armed Ediacara fossil preserved in contrasting taphonomic windows from China and Australia. Geology 36:867–870.Google Scholar