Multiple phyla, one time resolution? Similar time averaging in benthic foraminifera, mollusk, echinoid, crustacean, and otolith fossil assemblages

Abstract Time averaging of fossil assemblages determines temporal precision paleoecological and geochronological inferences. Taxonomic differences in intrinsic skeletal durability are expected to produce mismatch between co-occurring species, but the importance this effect is difficult assess due lack direct estimates time for many higher taxa. Moreover, burial below taphonomic active zone early diagenetic processes may alleviate taxonomic disintegration rates subsurface sediments. We compared across five phyla major carbonate producers a sediment core from northern Adriatic Sea shelf. dated individual bivalve shells, foraminiferal tests, tests isolated plates irregular regular echinoids, crab claws, fish otoliths. In spite different architecture, mineralogy, life habit, all taxa showed very similar varying ~1800 ~3600 yr (interquartile age ranges). Thus, remains echinoids crustaceans—two groups with multi-elemental skeletons assumed have low preservation potential—can still undergo extensive mixing comparable that mollusk shells. The median ages differed by as much ~3700 yr, reflecting species-specific timing seafloor colonization during Holocene transgression. Our results congruent sequestration models invoking minimize among These together variability production can overrule effects determining resolution multi-taxic assemblages.