From central Panama eastward into the Chocó region, and the Caribbean coastal region, the lower Magdalena Valley, and the north-central portion (César, Norte de Santander, and La Guajira) of Colombia, extending into adjacent coastal regions of Venezuela to the Orinoco Delta.
Not stated in original description; ANSP 6781, according to Malnate, 1971, Proc. Acad. Nat. Sci. Philadelphia 123:345-375[365].
Type-locality: Venezuela; restricted to Maracaibo, Zulia, Venezuela, by Roze, 1955, Acta Biol. Venezuélica 1:453-500[479].
Four subspecies, namely M. d. dissoleucus (Cope, 1860), M. d. dunni Barbour, 1923, M. d. melanogenys (Cope, 1860), and M. d. nigrirostris Schmidt, 1858, were recognized by Roze, 1983 [dated 1982], Mem. Inst. Butantan 46:305-338[320-321]. Roze, 1994, Bull. Maryland Herpetol. Soc. 30:177-185[180] elevated M. b. meridensis to species.
