Texas antelope squirrel

Adults can measure up to 220–235 millimetres (8.7–9.3 in) long, and weigh 99–112 grams (0.218–0.247 lb). They have a white stripe along the side of their torso, highlighted with black markings both above and below the stripe. The rest of the fur is grey with either black or brown markings, with the exception of the underside of the tail which is also white. They are active throughout the year and do not hibernate. They are thought to have evolved to their present state by the Clarendonian period (13,600,000 to 10,300,000 years ago). The breeding cycle begins in February, with one to two litters of between five and fourteen young raised each year. The young remain in the nest until they are about a quarter grown, which coincides with the move to solid food. Their diet includes insects, seeds and berries, including the fruit and seeds of a variety of cactus species. One adult found in 1905 had eaten the fruit of Opuntia engelmannii in sufficient quantities that its flesh was tinted purple.