About Sonora palarostris (Klauber, 1937)
Sonora palarostris has black, yellow or whitish, and red cross-bands, which makes it look very similar to the Sonoran coral snake (Micruroides euryxanthus). The common color-based venom identification mnemonic 'red on yellow kill a fellow, red on black, friend of Jack' does not work for this species. Unlike venomous Sonoran coral snakes, which have black snouts, Sonora palarostris has a yellow snout and is not venomous. Another key difference is that Sonoran coral snake bands wrap completely around the body, while Sonora palarostris has a solid yellow belly. At midbody, its smooth dorsal scales are arranged in 15 rows. It has between 141 and 181 ventral scales, and between 34 and 64 divided subcaudal scales. The maximum total adult length, including the tail, is 43 cm, or 17 inches. Sonora palarostris is native to the southwestern United States and northwestern Mexico. In the United States, it is only found in Organ Pipe Cactus National Monument, located in western Pima County, Arizona. The subspecies found at this location is called the Organ Pipe shovelnose snake, Sonora palarostris organica. In Mexico, the species is only found in the state of Sonora.
