Palaeoecology and taphonomy of spatangoid-dominated echinoid assemblages: A case study from the Early-Middle Miocene of Sardinia, Italy

A low energy, moderately deep, outer sublittoral environment with high rates of bioturbation and episodes of sediment deposition by storms is inferred. Interspecific competition among deposit-feeding echinoids appears to be limited by their different burrowing depths, feeding strategies and resource partitioning. The gregarious behaviour of spatangoid echinoids, their habitat in quiet, deeper environments and episodes of rapid deposition seem to represent the main factors leading to this spatangoid-bearing deposit. Since both shallow- and deep-burrowing spatangoid echinoids are well represented as complete specimens, mode of life does not appear to play a major role in their preservation potentials.