Panda Updates – Friday, July 8
One of the giant pandas’ most interesting features is the pseudothumb. This extension of the wrist bone acts almost like a sixth digit and allows them to hold bamboo in a groove between the pseudothumb and their other digits. Scientists have been talking about the pandas’ pseudothumbs for a long time, too!
In 1939, the British naturalist Frederic Wood Jones remarked that the pseudothumb “usurps the place of the true thumb and simulates all its movements.”
D. Dwight Davis, curator of zoology at the Chicago Natural History Museum, wrote an entire book about panda morphology! The pseudothumb stuck out (forgive the pun) to him, too. In his 1964 book, The Giant Panda: a Morphological Study of Evolutionary Mechanisms, he wrote, “The radial sesamoid is the most extraordinary bone in the fore foot.” That’s high praise – his chapter about the fore foot is 84 pages long!
Popular science author Stephen Jay Gould reflected in his essay, “The Panda’s Thumb” (published in his 1980 book of the same title) that, “The panda’s true thumb is committed to another role, too specialized for a different function to become an opposable manipulating digit. So the panda must use parts on hand and settle for an enlarged wrist bone and a somewhat clumsy, but quite workable, solution.”
Giant pandas are amazing animals that have evolved incredible adaptations to their diet of bamboo, inspiring scientists for decades! I hope they inspire your sense of wonder for the natural world as well!
POCOCK, R. The Prehensile Paw of the Giant Panda. Nature 143, 206 (1939). https://doi.org/10.1038/143206b0
Chicago, U.S.A. : Chicago Natural History Museum. (1964, January 1). The giant panda : A morphological study of evolutionary mechanisms : Davis, D. Dwight (Delbert Dwight), 1908-1965 : Free download, Borrow, and streaming. Internet Archive. Retrieved June 26, 2022, from https://archive.org/details/giantpandamorpho03davi/page/6/mode/2up
Gould, S. J. (1980). From Stephen Jay Gould, the panda’s thumb – UW faculty web server. Retrieved June 26, 2022, from https://faculty.washington.edu/lynnhank/Gould.pdf
Keeper III, Mammals