Fossilization potential of marine assemblages and environments

AbstractThe fossil record provides the only direct record of the history of life, but it is an incomplete one. Discriminating between what is absent and what is simply not preserved is critical to macroevolutionary and macroecological inferences. A comparison of diversity data in over 20,000 modern marine assemblages from the Ocean Biogeographic Information System database (OBIS) with fossil occurrence data from the Paleobiology Database (PBDB) yielded a global assessment of assemblage-level fossilization potential. We used two different metrics, taxon fossilization potential and within-environment fossilization potential, to assess the proportion of taxa in a modern community with PBDB occurrences or with PBDB occurrences in the same environment, respectively. Taxon fossilization potential of marine genera varies between environments, from 34% in shallow and deep water to 44% in coral reefs, 51% on seamounts, and 15% in pelagic assemblages. Within-environment fossilization potential, in contrast, does not exceed 32% (in shallow water), a lower value than that obtained in other studies, and it may be zero (on seamounts and pelagic environments). These differences are mainly a product of representation in the rock record and sampling biases rather than taxon duration.