Giant panda years ago) from the main ursine stock; since it is the most basal member of the group, it is equidistant from all other extant ursids. The giant panda has been referred to as a living fossil. Despite the shared name, habitat type, and diet, as well as a unique enlarged bone called the "pseudo thumb" (which helps them grip the bamboo shoots they eat) the giant panda and red panda are only distantly related. The word "panda" was borrowed into English from French, but no conclusive explanation of the origin of the French word "panda" has been found. The closest
Giant panda plant material through the short, straight digestive tract. It is also noted, however, that such rapid passage of digesta limits the potential of microbial digestion in the gastrointestinal tract, limiting alternative forms of digestion. Given this voluminous diet, the giant panda defecates up to 40 times a day. The limited energy input imposed on it by its diet has affected the panda's behavior. The giant panda tends to limit its social interactions and avoids steeply sloping terrain to limit its energy expenditures. Two of the panda's most distinctive features, its large size and round face, are adaptations to its bamboo