Minmi was a small ankylosaur. As a basal member of the family it was not diagnostic in appearance when compared to Ankylosaurus or other members of other families (such as Stegosaurus or Tyrannosaurus). The turtle-like beak of Minmi was actually less acuminate than the beaks of later members of its family; that made the beak more tortoise-like in appearance than snapping turtle-like. The eyes, like other ankylosaurs, were rather small meaning that there are two behavioral situations that are more plausible as living scenarios: 1) Minmi may have been an extraspecies member of other herds (such as hadrosaur herds) to survive or 2) Minmi may have been a loner (like other ankylosaurs) that used a heightened sense of smell to overcome poor eyesight.
Ossified scutes and an array of spikes were preserved with the two nearly complete specimens as well as in the varied remains that have been discovered as bits and pieces. Regardless, the evidence for the placement of the ossified scutes exists and the assembly of the completed skeleton can be created with a fairly good amount of accuracy. As with other ankylosaurs the rib cage and gastralia are compressed into a small anteriorly placed thoracic basket. The belly of the beast, so to speak, was not as small as the skeletal drawing implies; the belly most likely ballooned out laterally like a modern interpretation of Ankylosaurus (check out episode 6 of Walking with Dinosaurs).