Fossils of Riojasuchas are found in the Los Colorados Formation, a Late Triassic unit in Argentina, and date to approximately 217 to 215 million years ago. At that age, it is the youngest ornithosuchid known. It lived alongside the protosuchid Hemiprotosuchus; the sphenosuchid Pseudohesperosuchus; the stagonolepidid Neoaetosauroides; the melanorosaurid Strenusaurus; and the riojasaurid Riojasaurus.