chinchilla, (genus Chinchilla), either of two South American species of medium-sized rodents long valued for their extremely soft and thick fur. Once very common, chinchillas were hunted almost to extinction. They remain scarce in the wild but are raised commercially and also sold as housepets. All chinchillas in captivity are descended from 13 animals taken into the United States in 1927. Chinchillas weigh up to 800 grams (1.8 pounds) with a compact body up to...