The research was led by Xing Lida, an associate professor at China Geo University, Niu Kecheng, executive director of the World Museum of Natural History at the vertebrate paleontology Institute of China Academy of Sciences, and Zou Jingmei, an American researcher at the Institute of Paleoanthropology. This paper was published in Science Report.

This specimen is collected by the World Stone Natural History Museum in Liang Ying, and comes from the Hu Kang River Basin in Kachin State, northern Myanmar. Amber here was produced about 654.38 billion years ago, providing a unique record of forest ecosystem. This specimen did not preserve many bones of feet, but the skin recorded the outline of bird feet. There were a lot of hairs on the skin surface of these ancient bird feet. In addition, the specimen also preserved a very rare feather with a spindle as the main part.

"The claw of this specimen is large, curved and relatively flat, and its cross-sectional shape is similar to that of living arboreal birds, but different from that of terrestrial animals; The distal toe joint of the specimen is longer, which is a feature of arboreal birds, while the proximal toe joint of terrestrial birds is longer. " Xing Lida said.

The most interesting thing is that its toes are very thick, which is different from all the bird fossils found in this area before. Its outer toe, the fourth toe, has a laterally elongated toe pad, which is very thick relative to the two inner toes (the second and third toes). Strong toes are similar to living birds of prey, which may indicate that the specimen is a small aerial insect-eating bird.

This unique foot shape reflects the differences in the way birds catch prey. This type of foot has not been found in the local fossil record, which shows the diversity of birds in the dinosaur era. (Cui Xueqin)