Scientists used to think the little gray mouse roaming the island of Cyprus was just a house mouse brought by human settlers nine or ten thousand years ago. As it turns out, they were very wrong. Mus cypriacus , the first new species of mammal described from Europe in 100 years, shows an affinity to fossils dated well before the human colonization. It is, in fact, the only pre-human rodent still living on Cyprus. The term "living fossil" is overused, but, to mammologists, the mouse is a window to the long-ago development of the region's mammalian fauna.
Thanks once again to Kris Winkler, who could put me out of a job if she started her own blog :)