Skip to main content Accessibility help

Unusually variable paleocommunity composition in the oldest metazoan fossil assemblages

  • Seth Finnegan (a1), James G. Gehling (a2) and Mary L. Droser (a3)


Recent excavations of Ediacaran assemblages have revealed striking bed-to-bed variation in diversity–abundance structure, offering potential insight into the ecology and taphonomy of these poorly understood early Metazoan ecosystems. Here we compare faunal variability in Ediacaran assemblages to that of younger benthic assemblages, both fossil and modern. We decompose the diversity of local assemblages into within-collection (α) and among-collection (β) components and show that β diversity in Ediacaran assemblages is unusually high relative to younger assemblages. Average between-bed ecological dissimilarities in the Phanerozoic fossil record are comparable to within-habitat dissimilarities typically observed over meter to kilometer scales in modern benthic marine habitats, but dissimilarities in Ediacaran assemblages are comparable to those typically observed over 10–100 km scales in modern habitats. We suggest that the unusually variable diversity–abundance structure of Ediacaran assemblages is due both to their preservation as near snapshots of benthic communities and to original ecological differences, in particular the paucity of motile taxa and the near lack of predation and infaunalization.

  • View HTML
    • Send article to Kindle

      To send this article to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the or variations. ‘’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Unusually variable paleocommunity composition in the oldest metazoan fossil assemblages
      Available formats

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Unusually variable paleocommunity composition in the oldest metazoan fossil assemblages
      Available formats

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Unusually variable paleocommunity composition in the oldest metazoan fossil assemblages
      Available formats


This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (, which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.


Hide All

Data and code available from the Harvard Dataverse Repository:



Hide All
Bambach, R. K. 1977. Species richness in marine benthic habitats through the Phanerozoic. Paleobiology 3:152167.
Bambach, R. K., Droser, M. L., and Sepkoski, J. J. Jr. 1991. Secular changes in Phanerozoic event bedding and the biological overprint. Pp. 299312 in Einsele, G., Ricken, W., and Seilacher, A., eds. Cycles and events in stratigraphy. Springer-Verlag, Berlin.
Baselga, A. 2010. Multiplicative partition of true diversity yields independent alpha and beta components; additive partition does not. Ecology 91:19741981.
Beck, J., Holloway, J. D., and Schwanghart, W.. 2013. Undersampling and the measurement of beta diversity. Methods in Ecology and Evolution 4:370382.
Bobrovskiy, I., Hope, J. M., Ivantsov, A., Nettersheim, B. J., Hallmann, C., and Brocks, J. J.. 2018. Ancient steroids establish the Ediacaran fossil Dickinsonia as one of the earliest animals. Science 361:12461249.
Bowyer, F., Wood, R. A., and Poulton, S. W.. 2017. Controls on the evolution of Ediacaran metazoan ecosystems: a redox perspective. Geobiology 15:516551.
Bush, A. M., and Bambach, R. K.. 2004. Did alpha diversity increase during the Phanerozoic? Lifting the veils of taphonomic, latitudinal, and environmental biases. Journal of Geology 112:625642.
Callow, R. H. T., Brasier, M. D., and McIroy, D.. 2013. Discussion: “Were the Ediacaran siliciclastics of South Australia coastal or deep marine?” by Retallack et al. , Sedimentology, 59, 12081236. Sedimentology 60:624–627.
Caron, J.-B., and Jackson, D. A.. 2008. Paleoecology of the greater phyllopod bed community, Burgess Shale. Palaeogeography, Palaeoclimatology, Palaeoecology 258:222256.
Chen, Z., Chen, X., Zhou, C., Yuan, X., and Xiao, S.. 2018. Late Ediacaran trackways produced by bilaterian animals with paired appendages. Science Advances 4:eaao6691.
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 29:527544.
Coutts, F. J., Gehling, J. G., and García-Bellido, D. C.. 2016. How diverse were early animal communities? An example from Ediacara Conservation Park, Flinders Ranges, South Australia. Alcheringa: An Australasian Journal of Palaeontology 40:407421.
Darroch, S. A. F., Laflamme, M., and Clapham, M. E.. 2013. Population structure of the oldest known macroscopic communities from Mistaken Point, Newfoundland. Paleobiology 39:591608.
Darroch, S. A. F., Laflamme, M., and Wagner, P. J.. 2018. High ecological complexity in benthic Ediacaran communities. Nature Ecology and Evolution 2:15411547.
Droser, M. L., and Gehling, J. G.. 2008. Synchronous aggregate growth in an abundant new Ediacaran tubular organism. Science 319:16601662.
Droser, M. L., and Gehling, J. G.. 2015. The advent of animals: the view from the Ediacaran. Proceedings of the National Academy of Sciences USA 112:48654870.
Droser, M. L., Gehling, J. G., Tarhan, L. G., Evans, S. D., Hall, C. M. S., Hughes, I. V., Hughes, E. B., Dzaugis, M. E., Dzaugis, M. P., Dzaugis, P. W., and Rice, D.. 2017. Piecing together the puzzle of the Ediacara Biota: excavation and reconstruction at the Ediacara National Heritage site Nilpena (South Australia). Palaeogeography, Palaeoclimatology, Palaeoecology 513:132145.
Erwin, D. H., and Tweedt, S.. 2012. Ecological drivers of the Ediacaran–Cambrian diversification of Metazoa. Evolutionary Ecology 26:417433.
Finnegan, S., and Droser, M. L.. 2008. Reworking diversity: effects of storm deposition on evenness and sampled richness, Ordovician of the Basin And Range, Utah and Nevada, USA. Palaios 23:8796.
Gehling, J. G., Narbonne, G. M., and Anderson, M. M.. 2000. The first named Ediacaran body fossil, Aspidella terranovica. Palaeontology 43:427456.
Hautmann, M. 2014. Diversification and diversity partitioning. Paleobiology 40:162176.
Ichaso, A., Dalrymple, R., and Narbonne, G. M.. 2007. Paleoenvironmental and basin analysis of the late Neoproterozoic (Ediacaran) upper Conception and St. John's groups, west Conception Bay, Newfoundland. Canadian Journal of Earth Sciences 44:2541.
Jablonski, D. 2000. Micro- and macroevolution: scale and hierarchy in evolutionary biology and paleobiology. Paleobiology 26:1552.
Jost, L. 2007. Partitioning diversity into Independent alpha and beta components. Ecology 88:24272439.
Kidwell, S. M. B., and Daniel, W. J.. 1991. Taphonomy and time-averaging of marine shelly faunas. Pp.115209 in Allison, P. A. and Briggs, D. E. G., eds. Taphonomy: releasing the data locked in the fossil record. Plenum, New York.
Laflamme, M., and Darroch, S. A. F.. 2015. Palaeobiology: ecological revelations in Ediacaran reproduction. Current Biology 25:R1047R1050.
Levin, L. A. 2003. Oxygen minimum zone benthos: adaptation and community response to hypoxia. Oceanography and Marine Biology 41:145.
Lyons, T. W., Reinhard, C. T., and Planavsky, N. J.. 2014. The rise of oxygen in Earth's early ocean and atmosphere. Nature 506:307315.
MacGabhann, B. A. 2014. There is no such thing as the “Ediacara Biota.” Geoscience Frontiers 5:5362.
Marion, Z. H., Fordyce, J. A., and Fitzpatrick, B. M.. 2017. Pairwise beta diversity resolves an underappreciated source of confusion in calculating species turnover. Ecology 98:933939.
Mitchell, E. G., and Kenchington, C. G.. 2018. The utility of height for the Ediacaran organisms of Mistaken Point. Nature Ecology and Evolution 2:12181222.
Mitchell, E. G., Kenchington, C. G., Liu, A. G., Matthews, J. J., and Butterfield, N. J.. 2015. Reconstructing the reproductive mode of an Ediacaran macro-organism. Nature 524:343346.
Narbonne, G. M. 2005. The Ediacara Biota: Neoproterozoic origin of animals and their ecosystems. Annual Review of Earth and Planetary Sciences 33:421442.
Narbonne, G. M., Dalrymple, R. W., Wood, D. A., 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 40:13751391.
Populus, J., Vasquez, M., Albrecht, J., Manca, E., Agnesi, S., Al Hamdani, Z., Andersen, J., Annunziatellis, A., Bekkby, T., Bruschi, A., Doncheva, V., Drakopoulou, V., Duncan, G., Inghilesi, R., Kyriakidou, C., Lalli, F., Lillis, H., Mo, G., Muresan, M., Salomidi, M., Sakellariou, D., Simboura, M., Teaca, A., Tezcan, D., Todorova, V., and Tunesi, L.. 2017. EUSeaMap. A European broad-scale seabed habitat map., accessed 13 March 2018.
Reid, L. M., García-Bellido, D. C., Payne, J. L., Runnegar, B., and Gehling, J. G.. 2017. Possible evidence of primary succession in a juvenile-dominated Ediacara fossil surface from the Flinders Ranges, South Australia. Palaeogeography, Palaeoclimatology, Palaeoecology 476:6876.
Retallack, G. J. 2013. Ediacaran life on land. Nature 493:8992.
Sperling, E. A., Wolock, C. J., Morgan, A. S., Gill, B. C., Kunzmann, M., Halverson, G. P., Macdonald, F. A., Knoll, A. H., and Johnston, D. T.. 2015. Statistical analysis of iron geochemical data suggests limited late Proterozoic oxygenation. Nature 523:451454.
Stanley, S. M. 2008. Predation defeats competition on the seafloor. Paleobiology 34:121.
Tarhan, L. G., Droser, M. L., and Gehling, J. G.. 2015a. Depositional and preservational environments of the Ediacara Member, Rawnsley Quartzite (South Australia): assessment of paleoenvironmental proxies and the timing of “ferruginization.” Palaeogeography, Palaeoclimatology, Palaeoecology 434:413.
Tarhan, L. G., Droser, M. L., Planavsky, N. J., and Johnston, D. T.. 2015b. Protracted development of bioturbation through the early Palaeozoic Era. Nature Geoscience 8:865869.
Tarhan, L. G., Hood, A. v S., Droser, M. L., Gehling, J. G., and Briggs, D. E. G.. 2016. Exceptional preservation of soft-bodied Ediacara Biota promoted by silica-rich oceans. Geology 44:951954.
Tarhan, L. G., Droser, M. L., Gehling, J. G., and Dzaugis, M. P.. 2017. Microbial mat sandwiches and other anactualistic sedimentary features of the Ediacara Member (Rawnsley Quartzite, South Australia): implications for interpretation of the Ediacaran sedimentary record. Palaios 32:181194.
Tomašových, A., and Kidwell, S. M.. 2009. Fidelity of variation in species composition and diversity partitioning by death assemblages: time-averaging transfers diversity from beta to alpha levels. Paleobiology 35:94118.
Veech, J. A., and Crist, T. O.. 2010. Diversity partitioning without statistical independence of alpha and beta. Ecology 91:19641969.
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 24:3140.
Xiao, S., Droser, M., Gehling, J. G., Hughes, I. V., Wan, B., Chen, Z., and Yuan, X.. 2013. Affirming life aquatic for the Ediacara biota in China and Australia. Geology 41:10951098.
Zhao, F., Caron, J.-B., Bottjer, D. J., Hu, S., Yin, Z., and Zhu, M.. 2013. Diversity and species abundance patterns of the Early Cambrian (Series 2, Stage 3) Chengjiang Biota from China. Paleobiology 40:5069.

Unusually variable paleocommunity composition in the oldest metazoan fossil assemblages

  • Seth Finnegan (a1), James G. Gehling (a2) and Mary L. Droser (a3)


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed