been found in the Santa Maria and Caturrita Formations in Rio Grande do Sul (Paleorrota). Chilean aetosaurs are represented by one fragmentary genus, Chilenosuchus, from the Antofagasta Region. Aetosaurs have also been found in India, which, along with South America, was part of Gondwana during the Late Triassic. Early accounts of Indian aetosaurs were based on material from the Maleri Formation in south-central India, although these remains were too inadequate to assign specimens to any particular genus. Based on published descriptions, the Indian aetosaur fossils most closely resemble Longosuchus and Paratypothorax, which are considerably more specialized than most described Gondwanan aetosaurs. Reports of aetosaurs from Madagascar are based on probable crocodylomorph scutes. Supposed aetosaurian footprints and skeletal material from South Africa are also unsubstantiated. Footprints belonging to the ichnogenus Brachychirotherium are often associated with aetosaurs. Brachychirotherium are known from Rio Grande do Sul in Paleorrota, Brazil as well as Italy, Germany, the eastern United States, and many other aetosaur-bearing locales. They are also common in the southwestern United States, having been found in Canyonlands National Park and Dinosaur National Monument. Many of these tracks have a narrow gauge (meaning the left and right prints are placed closely together) and nearly overstep each other. A 2011 functional analysis of the skeleton of Typothorax coccinarum indicated that it had the range of movement necessary to produce the tracks. Classification Taxonomy Aetosaurs belong to Pseudosuchia, a clade of archosaurs that includes living crocodilians and is characterized by the distinctive structure of the ankle bones. Aetosaurs were traditionally referred to a (now obsolete) group called the thecodonts, which included all "primitive" crocodilian relatives that lived in the Triassic. With the rise of phylogenetics, aetosaurs were later placed in a group called Suchia, which included many Triassic crurotarsans as well as later crurotarsans, including crocodilians. Originally, all aetosaurs were considered members of the family Stagonolepididae. Early phylogenetic analyses split aetosaurs into two subfamilies, Aetosaurinae and Desmatosuchinae. Aetosaurines are characterized by projections called eminences on the dorsal paramedian osteoderms that are close to the midline of the back. Desmatosuchines have a few more distinguishing characteristics, including grooves on the dorsal paramedians that help them lock to the lateral plates in a tight articulation. Many desmatosuchines have long spikes projecting from the lateral plates. These spikes are especially prominent in Desmatosuchus. Aetosaurines, on the other hand, tend to have less spikes. Many aetosaurines, such as Aetosaurus and