dynastes

from The Century Dictionary.

• noun A genus of lamellicorn beetles, of the family Scarabœidœ or typical of a family Dynastidœ. It is restricted to forms having the external maxillar lobe with 3 or 4 small median teeth, no lateral prothoracic projections, and the last tarsal joint arcuate and clubbed. The type is D. hercules, the Hercules-beetle, the largest known true insect, having a length of about 6 inches, of which the curved prothoracic horn is nearly one half.