A one-of-a-kind fossil shows that so-called bat flies — tiny vampire insects that survive on the blood of bats — have been parasitizing the winged mammals and spreading bat malaria for at least 20 million years, scientists report in a pair of studies Friday.
"Bat flies are a remarkable case of specific evolution, animals that have co-evolved with bats and are found nowhere else," George Poinar, a zoologist at Oregon State University who led the studies, said in statement.

The highly specialized parasites, some of which only dine on specific bat species, spend most of their lives crawling through the animal's fur or on its wing membranes. They often have flattened, flealike bodies with long legs, and can be winged or wingless, depending on the species.
Bat flies fall into one of two families: streblidae and nycteribiidae, which are mostly found in the Eastern and Western Hemispheres, respectively. Currently, scientists have only identified nycteribiid flies as vectors, or transmitters, for bat malaria, but researchers have now learned that streblids may also be spreading the disease.
In the La Búcara mine, located in the Cordillera Septentrional mountain range of the Dominican Republic, Poinar and his colleagues uncovered an ancient malaria-carrying streblid fly entombed in amber.