Fossils have been found from the Santa Maria Supersequence of the late Carnian and early Norian stages, making Polesinesuchus one of the oldest aetosaurs.

It is composed of the parietal bone and the braincase as well as postcranial elements including cervical, dorsal, sacral and caudal vertebrae, both scapulae, a humerus, the ilium, pubis, ischium and tibia, a partial right pes, and anterior and mid-dorsal paramedian osteoderms.

[1] Polesinesuchus is known from a relatively small-sized individual with an estimated length of 76 centimetres (30 in), probably a two-year-old juvenile based on the incomplete fusion of neural arches to their centra in the whole vertebral column.

Polesinesuchus possess a short humerus with a robust shaft, and a dorsoventral and very low iliac blade with a long anterior process, exceeding slightly the pubic peduncle.

[1] Aetosauroides scagliai Aetosaurus ferratus Coahomasuchus kahleorum Neoaetosauroides engaeus Calyptosuchus wellesi Stagonolepis robertsoni Aetobarbakinoides brasiliensis Polesinesuchus aurelioi Typothorax Redondasuchus Tecovasuchus chatterjeei Rioarribasuchus chamaensis Paratypothorax andressorum Sierritasuchus macalpini Longosuchus meadei Lucasuchus hunti Acaenasuchus geoffreyi Desmatosuchus haplocerus Desmatosuchus smalli