A birthday party for six giant pandas was held at the Chongqing Zoo, located in the southwestern part of Chongqing, China.
It was a group birthday party for the twin pandas Xingxing and Chen Chen, who were born on June 10 last year, and the four giant pandas who were born on June 23, 2019: Xiongxiang, Jongchung, Shishi, and Qingqing.
For pandas born in June, the breeders made a great gift for a delicate birthday cake decorated with bamboo shoots and hearty fruits and vegetables.
By far the most popular was the bamboo cake.
Pandas have such a picky taste that bamboo accounts for 99% of their food.
[대나무 밝히는 식성 600만년 전부터 이어졌다?]
But new evidence has emerged that this unique diet dates back at least 6 million years.
This is because the unique sixth finger, a fake thumb used to hold bamboo, has also been found in ancient fossils.
According to the Los Angeles County Museum of Natural History, a research team led by Dr. Wang Xiaoming, a curator of vertebrate paleontology at the museum, identified and analyzed fake thumbs in the ancestor fossils of giant pandas and published the results in the scientific journal Scientific Reports.
The fossil, discovered in the Shuitangba area of Jiaotong City, Yunnan Province, in southern China, is analyzed to have come from ‘Airurarctos’, a genus of ancient pandas that lived in the late Miocene about 7 to 6 million years ago.
The thumb-like bone protruding from the wrist is the oldest evidence of a sixth finger possessed by a giant panda.
The existence of fake thumbs of pandas was first known about 100 years ago, but there are not many fossils, so records were only secured between 100,000 and 150,000 years ago.
Dr. Wang said, “The giant panda has moved to eating bamboo, which was abundant in subtropical forests, although low in nutrition, instead of meat and raspberries deep in the bamboo forest. It must have been the most important adaptation to eating sheep’s bamboo.”
[짧은 갈고리형 가짜 엄지는 대나무 먹고, 걷는데도 도움]
Through this fossil, the research team also identified the reason why the fake thumbs of modern giant pandas appear underdeveloped externally.
Airurarchtos showed a difference in that the fake thumb was longer and more straight than that of the giant panda, whereas the giant panda had a short hook-like shape.
The research team analyzed that the long bones evolved into short hooks in the process of using the fake thumb not only to grab and eat bamboo, but also to support the weight when walking in search of the next prey.
“5 to 6 million years is enough time for pandas to have longer fake thumbs, but evolutionary pressure to support their weight as they move makes them walk on fake thumbs,” said Dennis Su, associate professor at Arizona State University’s Institute of Human Origins at Arizona State University and co-author of the paper. It appears to have been made short and strong to be useful when grabbing bamboo without getting in the way.”
“The panda that evolved from a carnivorous ancestor to a bamboo-eating species would have had to overcome many obstacles,” said Dr. Wang. “He said.
