Species of the genus Chalcosoma can be found from Asia to Malaysia and like the stag beetles the female is quite insignificant in appearance to the male, has no horns and is also much smaller. Males of Chalcosoma often measure up to an impressive 120 mm (4.75 inches) in length. In C. atlas, the end of the cephalic horn has a rather broadened, upward curving hook-like section bearing very distinct, raised ridges. This feature is lacking in C. caucasus. Also, unlike the case C. caucasus, there is no dorsal spine on the cephalic horn of C. atlas.