Thorius boreas, commonly known as the boreal thorius, is a species of salamander in the family Plethodontidae. It is endemic to Oaxaca, Mexico, and only known from the Sierra Juárez. Its natural habitats are pine-oak and fir forests, often at forest edges. It is threatened by habitat loss (logging), although it does explain the dramatic decline that this species has seen. References Thorius Endemic amphibians of Mexico Fauna of the Sierra Madre de Oaxaca Amphibians described in 1994 Taxonomy articles created by Polbot