"Editor's Note: This story will be published in the December 2008 issue of Scientific American.
Survey the sky at twilight on a summer’s eve, and you just might glimpse one of evolution’s most spectacular success stories: bats. With representatives on every continent except Antarctica, they are extraordinarily diverse, accounting for one in every five species of mammal alive today. The key to bats’ rise to prominence is, of course, their ability to fly, which permits them to exploit resources that other mammals cannot reach. But their ascension was hardly a foregone conclusion: no other mammal has conquered the air. Indeed, exactly how these rulers of the night sky arose from terrestrial ancestors is a question that has captivated biologists for decades.
Answers have been slow in coming. This past February, however, my colleagues and I unveiled two fossils of a previously unknown species of bat that provides vital insights into this mysterious transformation. Hailing from Wyoming, the species—dubbed Onychonycteris finneyi—is the most primitive bat ever discovered. These fossils and others, together with the results of recent genetic analyses, have now led to a new understanding of the origin and evolution of bats. (...)"
Full article & Photo: Sciam.com