(CNN)Giant pandas are famous as noisy eaters. They just munching on bamboo and eat up to 99 pounds (45 kilograms) over 15 hours each day.
But their ancestors, like most bears, ate a much wider diet, including meat and the exclusive of modern pandas. The diet was thought to have evolved relatively recently. However, according to a new study , the panda's special passion for bamboo may have started at least 6 million years ago. This is probably because the plants are available all year round.
To survive only with undernourished bamboo, the modern panda (Ailuropoda melanoleuca) is a unique sixth finger that is a kind of thumb that can easily grab the bamboo stem and peel off the leaves. Was developed.
"Holding the bamboo stalks firmly to grind them into bite-sized pieces is probably the most important adaptation for consuming large amounts of bamboo," said the Museum of Natural History's Paleontology of Spine. Said Xiaoming Wang, a research author who is a curator of. Los Angeles County, in a statement.
Wang and his team have much earlier evidence that pandas have extra fingers in the form of fossil fingers dating back 6 to 7 million years, that is, all. Identified a bamboo meal. The fossils excavated in Yunnan Province in southwestern China were of the panda's ancestor known as Ailurarctos.
A new study published in the journal Scientific Reports on Thursday.
The sixth digit of the giant panda is not as elegant or dexterous as the human thumb, but the fact that this "unique form" has persisted for millions of years is that the giant panda survives. It suggests that it plays an essential function in.
Evolutionary compromise
But what was particularly confusing to the scientists involved in this study was the shorter modern giant panda with this fossilized structure. It was longer than the structure of. , I hooked my sixth finger.
Wang and his colleagues say that the sixth digit of modern pandas is short between the need to manipulate bamboo and the need to walk heavy bodies. We consider it an evolutionary compromise.
"5-6 million years should be enough for a panda to develop a longer fake thumb, but due to evolutionary pressure to move and bear its weight," The "thumb" seems to have been kept short. Dennis Sue, a co-author of the study, an associate professor of human evolution and social change at the Institute for Human Origins, Arizona State University, and a research scientist, said in a statement.