Competing hypotheses suggested to explain the observed environmental shifts range from global abiotic changes that occurred over kilometre scales to biotic factors acting over local scales (metre to kilometre), and include organism interactions such as burrowing and/or predation. ![]() The extent to which animals themselves drove these global changes is a matter of considerable debate. The diversification of early animals coincides with dramatic perturbations in the global environment, including changes to carbon cycling and a progressive but dynamic oxygenation of the oceans. 580–520 million years ago) is one of the most remarkable intervals in the history of life on Earth, witnessing the rise of macroscopic, complex animals in the global oceans. The Ediacaran–Cambrian transition (approx. Our results provide quantitative support for the ‘Savannah’ hypothesis for early animal diversification-whereby Ediacaran diversification was driven by patchiness in the local benthic environment. Higher species richness in shallow-water Ediacaran assemblages compared to deep-water counterparts across the studied time-interval could have been driven by this environmental patchiness, because habitat heterogeneities increase species richness in modern marine environments. ![]() The local patchiness within shallow-water communities may have been further accentuated by the presence of grazers and detritivores, whose behaviours potentially initiated a propagation of increasing habitat heterogeneity of benthic communities from shallow to deep-marine depositional environments. Shallow-marine (nearshore) palaeocommunities were heavily influenced by local habitat heterogeneities, in contrast to their deeper-water counterparts. ![]() The studied palaeocommunities exhibit marked differences in the response of their component taxa to sub-metre-scale habitat heterogeneities on the seafloor. To investigate how broad-scale environment influenced the community ecology of early animal ecosystems, we employed spatial point process analyses (SPPA) to examine the community structure of seven late Ediacaran (558–550 Ma) bedding-plane assemblages drawn from a range of environmental settings and global localities. The broad-scale environment plays a substantial role in shaping modern marine ecosystems, but the degree to which palaeocommunities were influenced by their environment is unclear.
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