What is "typothoracisinae"

Typothoracisinae is a clade of aetosaurs within the subfamily Aetosaurinae. It is a stem-based taxon defined as all aetosaurs closer to Typothorax than to Stagonolepis or Desmatosuchus. As with many aetosaur taxa, most of the synapomorphies that diagnose the clade are found in the osteoderms. These include a strongly acute angle of flexion between the dorsal and lateral flanges of the dorsal and lateral plates and triangular-shaped pelvic and anterior caudal dorsal lateral plates possessing semicircular borders and hook-like eminences.