On this day, 44 years ago, on December 1, 1981 (November 6, 1981 in the lunar calendar), extremely large dinosaur fossils were discovered in Japan. In early December 1981, Japan discovered an animal fossil in Iwaizumu-cho, Shimonoseki Prefecture. After investigation and identification by domestic and foreign paleontological research experts, it was confirmed to be the forelimb of the largest terrestrial dinosaur about 100 million years ago-the brontosaurus. Part of this provides very precious data for textual research and research on the historical and geographical changes of the island country of Japan. From this, experts concluded that 100 million years ago, the Japanese archipelago and the mainland were connected, bringing to an end the long-standing academic debate over Japan's history and geographical changes. The fossils were found in the middle generation strata known as the Gonggu Formation and are about 50 centimeters long and 20 centimeters wide. So far, it has been discovered one after another in North America, Europe, Africa and the mainland of China, and this is the first time that such a giant dinosaur fossil has been discovered in Japan.