Although it was a lobe-finned fish Strunius' fins were supported by fin rays, which are more associated with ray-finned fish. However, its skull was composed of two articulating halves, a feature characteristic of the lobe-finned rhipidistians. The skull was also divided by a deep articulation, with both halves probably connected by a large muscle, increasing the power of the bite. The same system is seen in coelacanths and the better-known Eusthenopteron.
Compared to other lobe-finned fishes, Strunius had a rather short, stubby body, and was just 10 centimetres (4 in) long. It was covered in large, round, bony scales, and probably fed on other fishes.