This is a collage of three "detail crops", showing what appear to be (small) serrations on the outer edge of the mesotibia. A serrate outer edge of the middle tibia is mentioned as a distinguishing character for the species Ripiphorus rex, on pg. 208 of Evans & Hogue(1)...as pointed out by Edward Ruden on this forum.

The serrations are most apparent in the middle sub-image of the three, as small downward pointing "nubs" near the bottom-right edge of the tibia. In the right-most sub-image of the triptych, the "nubs" are seen face-on, and appear as a thin medial stripe of irregularly darkened spots. In the left-most sub-image, the small nubs are mostly beyond the right edge of the tibia...and their presence is only vaguely intimated as a roughness along that edge.

For more complete info on this post, see 1st image in the series.