Quantitative morphology of the panda brain in comparison with the brains of the raccoon and the bear.

The quantitative development of brain and brain components with respect to body-size is discussed comparatively for the Chinese Giant Panda, the Canadian Raccoon and the American Black Bear. The panda ranks highest in encephalization as well as in relative volumes of neocortex, cerebellum and six other parts. The raccoon exhibits the strongest development of olfactory elements. The bear stays below the other species, showing but a single index that is superior to the corresponding index in one of them only. These results must be considered within the context of recent debates on the systematic position of the panda. This animal appears to have followed a partly independent evolutionary pathway, although it seems to stand somewhat closer to the raccoon than to the bear, contrary to other views. New comparative eco-ethological studies of the three species, as a complement to our neuromorphological approach, would certainly clarify the status reached by the panda at the end of its long and lonely evolution.