Evolution of the family Ailuridae: origins and Old-World fossil record

The red panda family, the Ailuridae, is unusual because its only extant representative is a derived form, far removed from the group's morphotypical condition. Effectively, the extreme adaptations of the red panda skull and dentition for a vegetarian diet imply that the study of the fossil record is essential if we are to gain an understanding of the original biology and ecology of the ailurids. Fossil ailurids have remained frustratingly rare and fragmentary findings for many decades, but recent years have seen a dramatic improvement of their record. This has been especially the case with the recent finds of dramatically complete remains of the simocyonine Simocyon batalleri from Batallones-1 in Madrid, Spain, and of the ailurine Pristinailurus bristoli from Gray Fossil Site in Tennessee, United States. Taking into account the information provided by these and other recent findings, it is now possible to gain a more complete picture than ever before of the true place of ailurids within the Carnivora, and of the evolutionary processes that led to the remarkable convergences between the only living ailurid and the unrelated giant panda. In this chapter, we present the early evolution of the ailurids, its Old-World fossil record, and the implications of the palaeontological evidence for the position of the ailurids among other carnivoran families.