The Sumichrasts vesper rat (Nyctomys sumichrasti), seen from below

Sumichrast's vesper rat is a rodent of the family Cricetidae found from southern Mexico to Panama. It is named for François Sumichrast, the collector of the first specimen, and its closest relative is probably Hatt's vesper rat, a similar, but slightly smaller, species from the Yucatán Peninsula.