Northern Alaska was on the biological dispersal path between Asia and North America because the tectonic blocks that make up this ancient Beringia region were in place by about 100 million years ago. Unfortunately, however, the exact faunal dynamics and impact of this strategic location are not well understood because of inadequate data and poorly defined geochronology in the terrestrial biota in Alaska.
A recent discovery of Sinoceratops in China asked a question for the faunal exchanges of the Ceratopsidae. This discovery indicates that real faunal exchanges were much more complicated than we thought. This situation explains why we need to explore ancient Beringia to find new materials. I have been worked with Dr. Anthony Fiorillo from Perot Museum of Nature and Science, Dallas, Texas, who is one of the best polar dinosaur researchers. Any new findings will give us a better understanding of the Cretaceous ecosystem and faunal changes in the polar region.
Fieldwork in Alaska is a different story from that in Mongolia. We have been working in Denali National Park, but outcrop is usually exposed to the peak of mountain ranges. So, we use a tiny helicopter to approach to the camp. Because this kind of chopper is too small and under unpredictable weather, riding a chopper is like a roller coaster. Fieldwork is mainly climbing. The Cantwell Formation (Maastrichtian) which is thousands of meters thick is exposed to central Alaska Range.
Here, we found several different dinosaur footprints, one of them is the first discovery of therizinosaurid footprint in Alaska. Therizinosaurid dinosaurs are a strange group because they have four pedal digits. Usually, theropod dinosaurs have three pedal digits. Because fossils are in National Park and located on the top of the mountain, we cannot take samples. Instead, we make a mold with a silicone compound.
The fieldwork in Alaska is even more challenging because of the wild bears. Bears are more dangerous when they have cubs. We encounter bears at least three times in the field. For surviving from the bears, the only defensive weapon we have is a bear spray and a bear bell to make a noise. Anything that makes smell such as food, must be put inside bear barrels so it will not decoy bears to our camp.