The application of guild and tier structure and energy flow in paleoecologic analysis: An example using parautochthonous death assemblages from a variable salinity bay

We examine the use of paleoproduction (the net production of somatic tissue over an individual's lifetime) and paleoingestion (the energy required to sustain the animal over its life span) in habitat tier and feeding guild analysis of paleocommunities, using modern death assemblages from a variable salinity bay. Community attributes evaluated by the abundance of the constituent species differed markedly from the same attributes described by paleoproduction or paleoingestion. Examination of the guild and tier structure from the perspective of paleoproduction and paleoingestion identified significant temporal changes in environmental optimality, probably related to changes in food supply, and in the division of resources amongst small and large species. Significant downcore changes in habitat optimality occurred only for the large species in the assemblage; those potentially most affected by changes in food supply. Tier structure was less variable than guild structure because species replacement always occu...