The role of microbes in decay and preservation: a Cambrian Explosion of animals and Lagerstätten.
(English)Manuscript (preprint) (Other academic)
The abrupt appearance of animals in the early Cambrian has been interpreted either as an explosive biological diversification or, alternatively, as an artefact resulting from a sudden increase in the probability of animal remains becoming fossilised. We attempt to reconcile these competing interpretations in exceptionally-preserved biota, which provide a vital part of our knowledge of the disparity and diversity of the Cambrian fauna. We assess the factors influencing the potential for exceptional fossil preservation using the brine shrimp Artemia salina as our experimental model. Following gut wall rupture, but prior to cuticle failure, internal, gut-derived microbes spread into the body cavity and formed pseudomorphs of tissues. Gut-derived microbes were shown to be the main factor mediating both decay and biofilm replacement and tissue stabilisation. This pattern of preservation is consistent with results from other experimental studies and with the nature of Burgess Shale type fossil remains. Thus, the evolution of a through-gut may have not only underpinned the ecological revolution that bilaterian diversification represents, but also catalysed the exceptional preservation of early bilaterian fossils.
Cambrian Explosion, palaeobiology, taphonomy, bilateria, metazoa
Other Earth and Related Environmental Sciences Evolutionary Biology Geology
Research subject Earth Science with specialization in Historical Geology and Palaeontology
IdentifiersURN: urn:nbn:se:uu:diva-216151OAI: oai:DiVA.org:uu-216151DiVA: diva2:689563