Family Lucanidae

The Lucanids or Stag beetles are the so called royalty of the beetle world with males of many species developing long antler like mandibles. These are normally associated with strong elongated heads capable of supporting their strong pincer movement. In the case of Cyclomnatus imperator found in Papua New Guinea, these elongated mandibles can represent up to 60% of the combined body length which can reach nearly 9cm (nearly 4 inches). In the case of Neolamprima adolphinae these mandibles grow upwards and outwards creating a somewhat bizarre appearance in the males. Females in nearly all Lucanid species are comparatively tiny and much less impressive to look at. Although not a regular occurrence, the large 'antered' males do sometimes use their mandibles for fighting, presumably for dominance, and serious injuries can be inflicted.

A good reference book is "Stag Beetles from all over the World" by Ikeda