Reiszorhinus olsoni (Sumida et al. 2010) Artinskian, Early Permian, ~280 mya, ~25 mm skull length, was derived from a sister to Thuringothyrisand phylogenetically preceded Romeria texana.
Distinct from Thuringothyris, the skull of Reiszorhinus had a slightly concave roof. The orbit diameter was shorter than the rostrum. There was no supratemporal edge or rim. The postorbital was truncated posteriorly. The squamosal did not descend to the ventral skull. No teeth were enlarged to fangs. The anterior mandible ascended and the ventral rim was convex.