Prairie dog and Clark in 1804. Lewis described it in more detail in 1806, calling it the "barking squirrel". On average, these stout-bodied rodents will grow to be between long, including the short tail, and weigh between . Sexual dimorphism in body mass in the prairie dog varies 105 to 136% between the sexes. Among the species, black-tailed prairie dogs tend to be the least sexually dimorphic, and white-tailed prairie dogs tend to be the most sexually dimorphic. Sexual dimorphism peaks during weaning, when the females lose weight and the males start eating more, and is at its lowest when the females
Prairie dog a few eastern locales. Despite the name, they are not actually canines. Prairie dogs are named for their habitat and warning call, which sounds similar to a dog's bark. The name was in use at least as early as 1774. The 1804 journals of the Lewis and Clark Expedition note that in September 1804, they "discovered a Village of an animal the French Call the Prairie Dog". Its genus, "Cynomys", derives from the Greek for "dog mouse" (κυων "kuōn", κυνος "kunos" – dog; μυς "mus", μυός "muos" – mouse). The black-tailed prairie dog ("Cynomys ludovicianus") was first described by Lewis