For comparison, the following are descriptions of P. imperator and P. dictator based on my research of the existing literature, as well as personal examination of specimens of both species.
Description of Pandinus imperator: Length 120-220 mm. Base color uniformly brown to reddish black, vesicle of telson usually lighter and often red in adults and lighter in juveniles. Carapace weakly granulated with deep sagittal furrow with forked, Y-shaped furrow on each side in posterior part. Tergites almost smooth, weakly granulated in posterior and lateral areas. Sternites smooth. Pectine teeth number 15-19. Spiniform formula of tarsomere II on legs I-IV = 4/3: 4-5/3: 4-5/2-3: 4-5/2-3. Tarsomere II with 2 spines on inclined anteroventral surface. Pedipalps with dorsal surface of chela granulated, chela with 3 internal trichobothria and 9-14 ventral trichobothria. Length to depth ratio of 4th metasomal segment greater than 2.
Description of Pandinus (Pandinopsis) dictator: Length 100-180 mm. Base color uniformly blackish brown to black, vesicle of telson usually lighter and often red in adults and lighter in juveniles. Carapace strongly granulated with shallow sagittal furrow with forked, Y-shaped furrow on each side in posterior part. Tergites granulated, particularly in the posterior and lateral areas. Sternites smooth, except the last one, which is granulated. Pectine teeth number 12-15. Pedipalps with dorsal surface of chela strongly granulated, chela with 2 internal and 4 ventral trichobothria.
Note: I have yet to examine the spiniform formulas of tarsomere II for this species, and I cannot find this information in the literature I currently have access to. Once one of my specimens molts, I will be able to look at the exoskeleton under a microscope and determine this.