A hidden benthic ecosystem in the Late Ordovician Soom Shale Lagerstätte (Cedarberg Formation, Cape Supergroup)
Résumé
Exceptionally well-preserved fossils in the Soom Shale Lagerstätte offer extraordinary insights into marine organisms that lived in southern Gondwana following Earth's second-largest mass extinction. This Late Ordovician assemblage is predominantly comprised of pelagic taxa, with an almost complete absence of benthic fauna, previously attributed to periodically anoxic-euxinic conditions that precluded seafloor occupation. We present the discovery of a meiofaunal benthic trace fossil assemblage which demonstrates a thriving and persistent small food web that lay hidden in the mudstones of the Cedarberg Formation. The sedimentology of these deposits suggests that the trace makers tolerated fluctuating