Oldest evidence of osteophagic behavior by insects from the Triassic of Brazil

This study reports the earliest known evidence of osteophagy by invertebrates in a continental setting from the Middle and Upper Triassic Santa Maria Supersequence, Paraná Basin, Brazil. Samples from the Dinodontosaurus Assemblage Zone (Pinheiros-Chiniquá Sequence – Middle Triassic) and the Hyperodapedon Assemblage Zone (Candelária Sequence – Upper Triassic) were analyzed and a number of trace morphologies were found, including tubes, holes and channels. We report the occurrence of Cubiculum inornatus from the Middle Triassic and Osteocallis mandibulus from the Upper Triassic and diagnose a new ichnospecies O. infestans isp. nov. The occurrence of these trace morphologies suggests that insect bone-modification behavior originated in Triassic Gondwanic environments, and dispersed during the Mesozoic, achieving a more cosmopolitan distribution during the Cretaceous.