Trophic levels and the observational completeness of the fossil record.

Abstract

Population density of benthic marine shelly species, as determined by their food requirements, seems to have an influence on the observational completeness of the fossil record of these potentially preservable faunas. Both comparisons made between life and death assemblages of bivalves and gastropods, and between Recent biocoenoses and Pleistocene molluscan faunas show that primary consumer species (filterers, browsers and detritivores) have a better chance of being incorporated into (and, subsequently, being sampled from) the fossil record than secondary consumer species (predators, scavengers and parasites). According to these results, it is suggested that the observational completeness of the fossil record of durably skeletonized species of invertebrates may be biased in favor of lower trophic level forms.