Jack Tseng and Camille Grohé, postdoctoral fellows in the Division of Paleontology at the American Museum of Natural History, are blogging from the field during an expedition to Inner Mongolia. The post below is from Camille. Read the first post from this expedition here.
From 1921 to 1930, the Central Asiatic Expedition led by Museum paleontologist Roy Chapman Andrews made good on its promise to provide exciting new discoveries on the geological history of Northern China and Mongolia. Among the most famous fossils excavated are the first Mongolian dinosaur nests, and from Inner Mongolia, gigantic fossil mammals such as Andrewsarchus mongoliensis, the largest meat-eating land mammal that ever lived.
On this trip, we’re lucky to have the chance to explore some of the same areas as the Andrews team, in particular, the Tunggur tableland, a formation in central Inner Mongolia that is one of the richest sites for mammalian fossils from the middle Miocene (about 16 to 11.5 million years ago).
The Central Asiatic Expedition provided the first insight into the amazing paleontological potential of Inner Mongolia, with a total of 28 species of mammals discovered. Among them were Platybelodon, a peculiar shovel-tusked mastodon; fossil deer; giraffes; antelopes; pigs; rhinos; bears; hyenas; big cats; rodents; rabbits; and the large herbivorous ungulate Chalicotherium, which is closely related to modern horses, rhinos, and tapirs.
But because of wars and political instability, only one brief expedition went back to the area over a span of about 60 years following the Central Asiatic Expedition discoveries. It wasn’t until the end of the 1980s that researchers regularly returned to the area through the Chinese Academy of Sciences’ Institute of Vertebrate Paleontology and Paleoanthropology (IVPP). One of the successive teams, led by Qiu Zhuding and Li Qiang, and joined by Xiaoming Wang—now a curator at the Natural History Museum of Los Angeles County and a co-leader, with Jack, of our current expedition—has done an amazing job of finding the historical localities of the Central Asiatic Expedition from photos and original descriptions. During that earlier expedition, sediment from the Tunggur was also screen washed for the first time. This technique, which is used to search for tiny fossils such as teeth and bone fragments, has permitted the description of many small fossil mammals such as hedgehogs, jerboas, picas, beavers, and bats.
Jack was part of four previous IVPP expeditions in Inner Mongolia, including one focusing on excavations at Baogeda Ula, a Late Miocene locality (about 11.5 to 5 million years old) located on the northeastern border of the Tunggur tableland. This is my first time in China—but we both are very excited about this new expedition. In addition to Xiaoming, Jack, and myself, our expedition team includes Wenqing Feng from the IVPP and Hongjiang Wang from the local cultural institution of Xilinhot (in Inner Mongolia). After a first stop at Xilinhot, about a 10-hour drive north from Beijing, we are going back to the Tunggur tableland, to the northeast at Baogeda Ula, and to the south at Dahongshan.
We expect to find new specimens that will help us understand the evolution of animals in Asia about 20 to 5 million years ago. For example, we are interested in mammal migration events between China and North America during this period as well as the evolution of the past environments in northern China while the planet underwent a global climate drying, or aridification.
We just use one car for our expedition, in contrast to the Central Asiatic Expedition, which used hundreds of camels for the transportation of gas, along with many cars. And even though this region is quite isolated, there have been some environmental changes over the past 80-plus years. One area we will visit was called “Wolf Camp” by the Andrews team because of the overwhelming number of wolves that called it home. But today, after years of hunting, there are no wolves to be seen. Recent drought has also made Tunggur drier, with fewer flowers, and new mining operations and the building of ranch fences are altering the general landscape.
This expedition is funded by the American Museum of Natural History and the National Natural Science Foundation of China. Additional support for this work was provided by the Franco-American Fulbright Scholar program, the AMNH Frick Fund (Paleontology), and the U.S. National Science Foundation.
Read the next post from the series here.