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Trophic analysis of communities consists of three methods: (1) measuring energy flow, (2) reconstructing food chains. and (3) describing feeding habit - substrate niche patterns. The latter two methods are useful in interpreting evolutionary patterns and depositional environments of paleocommunities. Because the preserved trophic structure may differ significantly from the actual structure. each study must test the hypothesis that preserved trophic structure is related to the environment. Analysis of several modem marine communities shows that their ‘preserved’ structure would not differ greatly from the actual structure. A comparison of some Holocene communities with Tertiary and Cretaceous communities shows that some communities from comparable environments have distinct feeding habit-substrate niche patterns. Differences can be explained by the evolutionary stage of the biosphere. Trophic structure seems to be partly related to over-all environmental stability, to food resources, and to substrate type.