''Chalcosoma engganensis'' is a large (35–60 mm) and heavy beetle. The body is shiny black. The male has a sharp horn (directed obliquely upward and forward) on the head. On each side of pronotum there are curved, forward directed horns. Across the head there is a short but powerful spike. This species differs from the normally developed specimens of the other ''Chalcosoma'' species in that horns are shorter, male can look a lot like small copies of ''

Chalcosoma moellenkampi The Moellenkampi beetle (''Chalcosoma moellenkampi''), is one of four large species of rhinoceros beetles from Southeast Asia belonging to the genus ''Chalcosoma''. The Moellenkampi beetles belong to the beetle family Scarabaeidae along with oth ...

''. The female lacks these horns and spikes, and is smaller.

References

Beetles of Asia Dynastinae {{Dynastinae-stub