 A second possible aetosaur nest site is known from northeastern Italy . The nests are preserved as depressions in carbonate rock that are circular or horseshoe @-@ shaped , with high ridges around the sides . They appear to be unusually complex for nests created by Triassic reptiles . <unk> footprints were found nearby that resembled aetosaurs , although they were not present in the same layer . Because the tracks were found so close to the nests , it is likely that aetosaurs built them . 
