They are generally classed as a group of saurischian dinosaurs. "Saturnalia" may be a basal saurischian or a prosauropod. Herrerasauridae is a family of carnivorous basal saurischian dinosaurs. In the redescription, the authors found the material to belong to a "possible indeterminate saurischian". The clavicle was present in saurischian dinosaurs but largely absent in ornithischian dinosaurs. The build of the pelvis shows it was a saurischian dinosaur. It was a small, lightly-built, basal saurischian dinosaur. The femur and the astragalus are clearly dinosaurian however, with the latter possessing saurischian characteristics. Benson and Brussatte (2012) found that "Chindesaurus" was a basal saurischian related to "Herrerasaurus". In this review, "Herrerasaurus" is found to be a basal saurischian, but not a theropod. Regardless, they are almost certainly saurischian. Previously, only carnivorous, saurischian theropods were known to reach such small sizes. The pelvis of "Achillobator" features plesiomorphic saurischian characteristics compared to other dromaeosaurids.