The Tibetan Plateau and the formidable Himalayan mountains to the south are known as the “Roof of the World,” with towering peaks and expansive high-altitude plains. Explorations over the past century, either for scientific or for personal, spiritual, or nationalistic purposes, are immortalized in books, documentaries, and urban myths. My team’s expeditions to Tibet began without much fanfare. Our goal was simple: to systematically document the fossils present in the remote western reaches explored previously by geologists but not vertebrate paleontologists.
Since 2006 we have focused our efforts in a stretch of badlands in the Zanda Basin. Zanda’s badlands cover an area larger than Yellowstone National Park and are transected by a river called the Langqen Zangbo, which flows westward into India. A group of us makes the pilgrimage yearly from Los Angeles to Beijing, where we set off in field vehicles on the seven-day cross-country trip to western Tibet. The final descent from the plateau into the basin is a sight to behold no matter how many times I return here for field work: With the permanently snowy peaks of the Himalayas as the backdrop, our vehicles snake through barren cliffs that take us backward through time as we pass deeper and deeper rock layers. Reminders of the perils of the expedition can be seen at the bottom of the cliffs, where fallen and crushed cars remain year after year. We finally reach the level of the Langqen Zangbo, where the small town of Zanda sits on a terrace overlooking the majestic river valley.
August 2010 started as a typical field season, except that it was the first time since our wedding that my wife, Juan, and I were on an expedition together. (We met while doing fieldwork in the northern Tibetan Plateau in 2005.) I was a graduate student at the University of Southern California and she at the University of Alberta. Our drivers skillfully navigated the intricate valleys on dirt trails to bring us close to rock exposures that looked promising from our satellite maps. We parked the vehicles just off the trail and split into small groups to search for fossil remains of extinct mammals and other animals.
Feeling caged in between the cliffs, I proposed to hike directly to the top with Gary Takeuchi, a good friend and experienced field paleontologist from the Page Museum of Rancho La Brea in Los Angeles. Juan decided to take another route, going up a different hill while prospecting. Gary and I bee-lined to the top of the cliffs, where the view was much better. Much to our dismay, we found no traces of fossils, not even a fragment. We received a call over the two-way radio from Juan; she had found some fossil bone fragments on a gentle slope about halfway down the adjacent hill. After getting the sense that the fragments were significantly weathered, Gary and I pressed on over the ridge into the unknown. Not a few minutes passed before we received another radio call, this time from Qiang Li of the Chinese Academy of Sciences; he took a look at what Juan has found and urged us to join them for further examination.
Without having found even a single piece of bone, Gary and I called off our hike and met Juan and Qiang. As we approached we could see numerous fist-sized fossil bone fragments scattered throughout the flat area they were standing in. Picking through them like an old lady picking through a basket of fruit, I looked for diagnostic bits and pieces to identify at least some of the fossils to a specific group of animals. (Almost all were mammals.) Toe bones of horses and rhinos, and limb bones of extinct antelopes were immediately apparent. Most of those species were already known from previous collections in the basin, so I was not greatly impressed with Juan’s find.
Then I saw a broken lower jaw that belonged to a carnivore.