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Photo credit:

Dick Bartlett

Common name

Southern Ridge-nosed Rattlesnake

Scientific name

Crotalus willardi meridionalis

Conservation Status

Data Deficient

Federal and State Protections

Range Map


Countries of Occurrence


Adult size

States or Providence 

Arizona (US), New Mexico (US), Sonora (MX), Chihuahua (MX), Durango (MX)


Species Description

This small rattlesnake can be found in the Mexican states of Durango and Zacatecas in wooded, high elevation areas. Its diet consists of birds, lizards, small mammals, and invertebrates, such as centipedes.

Similar to almost all other rattlesnakes, the venom of the southern ridge-nosed rattlesnake is hemotoxic.
Little else is known about the biology and ecology of this subspecies of ridge-nosed rattlesnake likely due to its isolated localities in unpopulated areas.

Fun fact: The subspecific epithet, "meridionalis," comes from the Latin meaning of south, "merīdiēs." The southern ridge-nosed rattlesnake is the southernmost subspecies of all ridge-nosed rattlesnakes of the US and Mexico.

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