Heterodon platirhinos (Latreille, 1801)
Key Characters: Enlarged upturned plate at tip of nose; underside of tail light; back scales keeled; anal plate divided; prefrontal scales contact each other.
Similar Species: Western Hog-nosed Snake. See the Key to Illinois Snakes for help with identification.
Subspecies: None are recognized.
Description: Medium-sized (up to 90 cm TL), stout-bodied snake highly variable in coloration and pattern. Usually gray, tan, or brown back with 20-30 dark blotches. Some individuals are olive, brown, or black with no blotches. Belly light or dark, but underside of tail always lighter than belly. Tail short, less than 22% of body length.
Habitat: Forest-edge habitats and dry, open woods on clay or sandy loam; sand areas of northern counties.
Natural History: This is the “puff adder” or “hissing viper” of folklore. Defensive behavior resembles that of western hognose snake. When first encountered, it commonly flattens the head and neck, hisses, feigns strikes (striking to the side rather than biting), releases feces and foul-smelling musk, then rolls onto its back with mouth open and appears to have died. If righted, it rolls over again. Mates in spring and lays 8-20 eggs in June, July, or August, the number depending on size of the female. Hatchlings range from 17 to 25 cm TL. Food consists mainly of frogs and toads. Main predators are raptors and other snakes.
Status: Common in regions of major sand deposits. Rare in Grand Prairie.
Etymology: Heterodon – heteros (Greek) meaning other, different; odon (Greek) meaning tooth; platirhinos – platys (Greek) meaning broad, wide, flat; rhinos (Greek) meaning nose, snout.
Original Description: Latreille, P.A. 1801. in Sonnini, C.S. & P.A. Latreille. Histoire Naturelle des Reptiles, avec Figures dissinees d’apres Nature. Chez Deterville, Paris. p. 32.
Type Specimen: Not designated.
Type Locality: “dans les environs de Philadelphie”.
Original Name: Heterodon platyrhinos Latreille, 1801
Nomenclatural History: Aside from a few minor spelling changes (platyrhinos, platyrhinus), the nomenclature of this species has been stable.