Ancient blood-sucker

A bat fly, preserved in amber.
(George Poinar, Jr., courtesy of
Oregon State University)

Bat flies are highly coevolved obligate ectoparasites of bats.  They live in the fur or on the wing membranes, where they feed on blood.  Today, there are some 500 species in two families.  We know now that they've been around a long - some 20 million years, infact.  Researchers at Oregon State University have discovered a fossil bat fly preserved in amber in what is now the Dominican Republic.  

Bats themselves go back some 50 million years, and it appears that they've been associated with this coevolved parasite for at least half that time.  The flies are known to carry a number of blood-born parasites, including Ebola.  This particular one harbored malaria, another reminder of just how far back these relationships go.