Horned Beetle

The differences between the Promeces and the Closteromerus
Promeces
Antennae 12 segmented, slender, and longer (atleast 1.5 times) than the body in males, females 11 segmented, slender, only slightly longer than body, last 4 segments approximately the same length.
Pronotum bright shiny with fine punctures (punctures not touching)
Closteromerus
Antennae 11 segmented (M+F), slender but becoming broader from the seventh segment (8 - 11 flattened and wider) segment 10 shorter than segment 11.
Pronotum has a glitter appearance caused by fine semi horizontal worm-like ridges.