Canis dirus was a large Pleistocene (2.6mya - 11.7 kya) canid. The latin name translates literally as the "fearsome dog", but is more commonly known as the dire wolf. Fossil remains are fairly common and have been found at over 100 sites in North America and several sites in South America. Without question, the most productive site of C. dirus fossils is the Rancho La Brea Tar Pits in Southern California, where over 200,000 specimens have been recovered (Merriam, 1912; Nowak, 1979; Kurtén & Anderson, 1980; Kurtén, 1984; Stock & Harris, 1992; Dundas, 1999; Anyonge & Roman, 2006; Anyonge & Baker, 2006).
The dire wolf thrived throughout a wide range of habitats. The South American range was dominated by arid savannahs, while North American habitats were grasslands, plains and mountainous forests. Its northern range extended into Southern Canada, but fluctuated significantly with glacial activity. The dire wolf became extinct throughout its range at the end of the Pleistocene, in both North and South America (Dundas, 1999).