The genus Coprophanaeus contains around 40 species distributed from the extreme southern USA to central Argentina, but most species occur in tropical South America.
There are 3 other similar species of giant carrion scarabs in the subgenus Megaphanaeus found in South America, whose distributions are:
The most similar species to Coprophanaeus lancifer is Coprophanaeus ensifer, which can be distinguished by slight differences in the shape of the horns and the surface of the wing cases.
There is also usually, but not always, a clear colour difference. Coprophanaeus lancifer is blue or purple, whilst Coprophanaeus ensifer is usually green.