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New bioerosion traces produced by insects in bones are reported from the Hyperodapedon Assemblage Zone of the Santa Maria Supersequence (Carnian, Brazil). The bones are assigned to a single rhynchosaur Hyperodapedon mariensis individual and among the traces, the ichnogenera Osteocallis (Osteocallis mandibulus, Osteocallis infestans, and Osteocallis isp.) and Amphifaoichnus (Amphifaoichnus isp.) are recognized, along with two morphotypes of indiscrete traces: clusters of grooves and borings. All the traces are assigned to the action of insects exploring the rhynchosaur carcass. Osteocallis and associated clusters of grooves are interpreted as feeding traces, but whether they represent necrophagic or osteophagic behavior is still uncertain. The lack of direct evidence for the ethological interpretation of Amphifaoichnus precludes its sole correlation with osteophagy, and other possibilities, such as the construction of temporary domiciles related to feeding or sediment moisture, are discussed. The traces analyzed here indicate that the insects explored a buried carcass, challenging the automatic association of Osteocallis and prolonged subaerial exposure of bones, placing insects as relevant taphonomic agents that affect the preservation of vertebrate carcasses. Additionally, the first appearance record of Amphifaoichnus is expanded back more than 140 Ma, indicating that complex behaviors employed by insects in bone exploration were already established in the early Late Triassic, shortly after the oldest records of invertebrate bioerosion in bones on continental settings. [ABSTRACT FROM AUTHOR]

Terrestrial tetrapod coprolites are abundant in the Middle to Late Triassic of southern Brazil, but only few specimens have been described in just a couple of papers. Here we revisit the already‐known specimens and describe new materials, including their size, shape, external modifications, matrix composition and rare inclusions. Regarding size and shape, the measurements of 152 specimens show that the Triassic coprolites of Brazil follow a normal distribution, in which length and width are positively correlated variables, so that they are not useful for taxonomic purposes. Notwithstanding, two ichnotaxa, Santamariacopros elongatus and Rhynchocopros soutoi, were previously described from the Middle/Upper Triassic Santa Maria Formation, based mainly on morphological (length/width ratio) and preservational features, but we discuss here the validity of such taxa. Once the Santa Maria Formation encompasses at least three tetrapod Assemblage Zones (AZ), Dinodontosaurus AZ, Santacruzodon AZ and Hyperodapedon AZ (from the oldest to the youngest, respectively), it is difficult to attribute these coprolites to any specific animal producers. In addition, the rarity of inclusions and the carbonated composition of the coprolites, related to early diagenetic processes, complicate this attribution too. Nevertheless, some rare inclusions as a hair‐like structure and a parasite egg were found in this study. Although the coprotaxonomy fails to represent the Santa Maria Formation coprolites and the recognition of their producers is a problematic task, these fossil dungs are important elements in the knowledge of the Middle to Late Triassic environments of southern Brazil. [ABSTRACT FROM AUTHOR]