Novas (1992) defined Dinosauriformes as a node-based clade containing the most recent common ancestor of Lagosuchus and Dinosauria, and all its descendants. Nesbitt (2011) provided a roughly equivalent definition, using Marasuchus and Passer domesticus (the house sparrow, a representative of dinosaurs). In his analysis, Dinosauriformes included dinosaurs, silesaurids, and Marasuchus, but not lagerpetids, which were considered to be an earlier-branching family of dinosauromorphs.
Novas (1992) defined Dinosauriformes as a clade based on the most recent common ancestor of Lagosuchus and Dinosauria, along with all its descendants. Nesbitt (2011) offered an approximately equivalent definition using Marasuchus and Passer domesticus (the house sparrow, representative of dinosaurs). In his analysis, Dinosauriformes included dinosaurs, silesaurids, and Marasuchus but not lagerpetids, which were considered a more ancient family of dinosauromorphs.