Oryzomys antillarum, the Jamaican rice rat, is an extinct rodent known from subfossils and specimens collected live in the 19th century. It probably became extinct late in that century, perhaps due to the introduction of the small Indian mongoose, competition with introduced rodents such as the brown rat, and habitat destruction in Jamaica. O. antillarum was a medium-sized rat, with a length of 120 to 132 mm (4.7 to 5.2 in), not including the tail; the skull was about 30 mm (1.2 in) long. The upperparts were reddish and graded into the yellowish underparts. The tail was about as long as the head and body, sparsely haired, and darker above than below. The species was similar in most respects to the rice rat Oryzomys couesi of mainland Central America, but had longer nasal bones, shorter perforations of the palate near the incisors, and more robust cheekbones. (This article is part of a featured topic: Oryzomys.)