Desmatosuchinae is one of the two
subfamilies of
aetosaurs, the other being
Aetosaurinae. It is a
stem-based taxon defined as all aetosaurs more closely related to
Desmatosuchus than the last common ancestor of
Desmatosuchus and
Stagonolepis. All
synapomorphies that diagnose the clade can be found in the
osteoderms. These include tongue-and-groove articulations for lateral plates present in dorsal presacral paramedian plates and large spikes on the lateral cervical, dorsal, and caudal plates.