Though its remains were initially referred to Ticinosuchus when discovered during the 1970s, in 2007 it was identified as a distinct genus with unique features of the pubis and maxilla.

[1] The maxilla has a straight lower edge with at least 12 large, knife-like teeth set in deep sockets and covered by interdental plates.

The possible quadratojugal fossil is thick and sharply angled, apparently contacting a long jugal but not the quadrate, unlike its relatives.

The acetabulum (hip socket) expands down the shaft of the pubis and is delineated from the front by a thick ridge which projects out as a tuberosity at its lower extent.

The femur is large and robust, with a prominent knob-like fourth trochanter overlooking a smaller knob which may be an area of diseased bone.

However, "Rauisuchia" is currently considered to be a paraphyletic grade of archosaurs incrementally closer to crocodilians, rather than a clade (a natural grouping defined by shared relations).

[3][2] Although most frequently compared with loricatans, Arganasuchus has yet to be properly incorporated into this newer understanding of crocodilian ancestry, and as a result its classification relative to other "rauisuchians" is poorly understood.

Brusatte et al. (2010) found weak support for a small clade of basal "rauisuchoids" (loricatans) containing Arganasuchus, Fasolasuchus, Stagonosuchus, and Ticinosuchus.

[4] França et al. (2011) found that Arganasuchus was an unstable "wildcard" taxon in their analysis, though a connection to Decuriasuchus, Prestosuchus, and Batrachotomus was one possibility.