Carpolestes simpsoni is an extinct species of Plesiadapiformes, which is one of the earliest primate-like mammals appearing in the fossil record during the late Paleocene. C. simpsoni had grasping digits but no forward-facing eyes. Weighing about 100 grams, C. simpsoni appeared adapted for an arboreal habitat. One large, nail-tipped toe opposed other toes, allowing a firm grip on branches. Like other species of Carpolestes, the dental morphology of C. simpsoni is specially adapted to eating fruit, seeds, and invertebrates.