G. cristatus differs from "G. rhampastinus" by having no teeth in the tip of the jaw and fewer teeth (~13 in each side of the upper jaw and ~12 in the lower versus 16 upper and 15 lower on each side for "G. rhamphastinus").
G. cristatus is distinguished from G. rhamphastinus by lacking molars at the jaw's anterior end, whereas it possesses fewer teeth (~13 on each upper jaw and ~12 on the lower jaw) compared to G. rhamphastinus (16 upper and 15 lower teeth per side).