Juliomys ossitenuis is a species of rodent in the family Cricetidae native to South America.
They can survive in habitats that accumulate heavy amounts of rain.
Three types of hair are present in the dorsal region of this species' fur: aristiform, setiform and villiform. The ventral coat is maize yellow, paws in dorsal view are light orange (apricot yellow and dark orange), tail is smooth and intensely bi-colored dorsoventrally, presence and absence of tufts of hair at the tip of the tail, and ventral coat banding pattern, with a gray base corresponding to approximately half and one third of the coat length.
