Jamaican Rice Rat

Oryzomys antillarum was a medium-sized rodent, about as large as O. couesi. According to Thomas's description, the upperparts were reddish, slightly brighter on the rump and more grayish on the head. The color of the upperparts graded into that of the underparts, which were yellowish. The hairs of the underparts were grayish at the bases. The small ears were black on the outer and yellow on the inner side and the upper surfaces of the hands and feet were whitish. The tail was nearly naked and was light brownish above and lighter below. Goldman wrote that the specimens in the USNM were rather more reddish, but their color may have been altered because they had been preserved in alcohol. Coues had described these as rusty brown above and washed with the same color below. Andrew Arata compared the USNM specimens with examples of the reddish Florida subspecies of the marsh rice rat, Oryzomys palustris natator, for Ray and found that they were more reddish than even the most strongly colored animals from Florida.

The skull was generally similar to that of O. couesi, as were the teeth. It was robust and bore well-developed supraorbital ridges (located above the eyes) on the braincase. The interparietal bone, part of the roof of the braincase, was small and narrow. The bony palate extended beyond the third molars. …