The Parson Russell has a relatively square outline, with a body about as long as the dog is tall. Compared to the Jack Russell Terrier, the Parson Russell has a longer head and a larger chest along with overall a slightly larger body size. The Parson retains the flat skull but not the elongated shape of the Fox Terrier, and with lower set ears. In addition, the Jack Russell Terrier has a greater variation in size, ranging between in height at the withers.