Hyperokynodon is known only from two specimens: a holotype snout and a cast of the underside of the skull roof. The holotype was found in Heilbronn, Germany, in the mid-1800s. It likely came from deposits in the Wartberg, a mountain that had several active quarries at the time. The cast, known as SMNS 55910, was found in a sandstone quarry east of the city of Heilbronn. SMNS 55910 is an impression of the underside of the skull table and includes parts of the palate and the edge of the orbit.