Reiszorhinus is an extinct genus of Early Permian captorhinid known from the United States. The type species is Reiszorhinus olsoni. Fossils have been found from the Waggoner Ranch Formation in north-central Texas. It is distinguishable by its recurved teeth and extremely large Meckelian foramen on the inner surface of the lower jaw. It has been considered a primitive member of its family because it has a single tooth along the margins of the jaws. While most single-tooth-rowed captorhinids are small, Reiszorhinus is relatively large. However, Reiszorhinus differs from other large captorhinids in that the cheek region is not wide and expanded.
