Naturalists know that the Big Bend's harsh conditions mask a tremendous diversity of living things. The Chihuahuan Desert is home to plants and animals found nowhere else on earth.

But did you know it was once home to an assortment of distinctive, endemic primates? Today, excavations are shedding light on this surprising part of West Texas history.

As primates ourselves, we can't help but take a special interest in the history of these mammals. It's a story that stretches back 65 million years.

Scientists say primates emerged in Southeast Asia in the early Paleocene Epoch, just after the disappearance of the dinosaurs.

For ages, they were limited to the Asian jungles. But about 5...