Isabela Jurigan
Fresia Ricardi-Branco
Paula Dentzien-Dias

Fossilized feces (coprolites) are remarkable tools for paleobiology and paleoecology assessment. Here they are used to reconstruct the Permian interactions between organisms that once composed a large interior sea at Western Gondwana. Coprolites from the Corumbataí Formation were retrieved from a distal tempestite layer and investigated about their morphology, texture, and food inclusions, applying hand sample description, petrographic analysis, EDS/SEM, and confocal microscopy. Seven morphotypes were recognized, which were probably derived from fishes, like xenacanthid sharks, basal Actinopterygii (Palaeonisciformes), petalodontids/dipnoan, and possible tetrapods, such as temnospondyls and diapsids. Four coprofabrics were also recognized and allowed the establishment of four different feeding/digestive strategies and, consequently, the definition of carnivorous-piscivorous predators as top predators, but also as occupants of intermediate trophic niches. Durophagic/deposit feeders were occupants of inferior trophic niches. This food web developed under stressful conditions, during a moment of aridization of the Paraná Basin, in association with ostracods and sponges’ proliferation, and during this moment palaeoniscoid fishes seem to have been the main exploited resource in the environment.

Palavras-chave: Fossilized fecesMicrofossil bonebedPrimitive fishPaleozoic ecosystem

Fresia Ricardi-Branco