Engagement of gear-like structures on mandibles of D. hercules during opening and closing; engaged regions of mandibles were exposed using a file. A Lateral view of the head from the left side; dotted lines indicate the position of the transverse section B interior view of the head from the ventral side C diagram of the engagement region; gear-like structures are emphasized by stipple. Abbreviations: R = right compound eye; L = left compound eye. Scale bar: 7 mm.

  Part of: Ichiishi W, Shimada S, Motobayashi T, Abe H (2019) Completely engaged three-dimensional mandibular gear-like structures in the adult horned beetles: reconsideration of bark-carving behaviors (Coleoptera, Scarabaeidae, Dynastinae). ZooKeys 813: 89-110. https://doi.org/10.3897/zookeys.813.29236