 The pattern of grooves and foramina on the head indicates that the circulation of the arteries in the head of "T. ucucha" follows the primitive pattern.The tegmen tympani, the roof of the tympanic cavity, overlaps the suspensory process of the squamosal bone.At the back of the mandible (lower jaw), there is a capsular process to receive the root of the lower incisor, which is absent in "T. hylophilus".