About Sciurus yucatanensis J.A.Allen, 1877
Dimensions and description: The Yucatan squirrel (Sciurus yucatanensis) measures 450–500 millimetres (18–20 in) in total length, and is larger than the eastern gray squirrel (S. carolinensis). It shares similar fur colours and patterns with Collie's squirrel (S. colliaei) and the variegated squirrel (S. variegatoides), but differs from these species in size. Adult individuals have a relatively long tail that reaches 240 mm (9.4 in) in length. Both sexes are the same size, with a body mass ranging from 341–475 grams (12.0–16.8 oz). Its pelage is coarse and harsh. The upper parts of the body are coloured black and grey, with additional yellow to ochraceous buff colourings. The lower body is coloured off-white, yellow-grey and black. The tail has a central white area with black on either side and well-defined black lines along it. Tail hairs are shorter than the hairs on the head and body. The face has a buff-coloured patch above the nose, and the sides of the head are mainly black. The narrow, pointed, tufted ears are grey, brown and white, and turn an off-white colour from November to February in northern populations and from February to April in southern populations. The skull of S. yucatanensis is short and broad, with an approximate total length of 57 mm (2.2 in), and the facial portion of the skull is particularly short.
