It is very unusual for horns to be well-developed in both the males and females of a species of scarab beetle - it is far more common for only the male to be armed.
But it is possible to detect small differences in the shape of the male and female horns, especially in well-developed, large individuals.
Smaller individuals, having less developed horns, look very similar. However, only the females have tarsi on their front legs, which are diagnostic.
The beetles probably enter same sex and mixed sex combats, using their horns to try to gain access to a burrow, as has been observed in a closely related species, Coprophanaeus ensifer (Otronen, 1988).