Ailuridae


Ailuridae is a family in the mammal order Carnivora. The family consists of the red panda and its extinct relatives.
Georges Cuvier first described Ailurus as belonging to the raccoon family in 1825; this classification has been controversial ever since. It was classified in the raccoon family because of morphological similarities of the head, colored ringed tail, and other morphological and ecological characteristics. Somewhat later, it was assigned to the bear family.
Molecular phylogenetic studies had shown that, as an ancient species in the order Carnivora, the red panda is relatively close to the American raccoon and may be either a monotypic family or a subfamily within the procyonid family. An in-depth mitochondrial DNA population analysis study stated: "According to the fossil record, the Red Panda diverged from its common ancestor with bears about 40 million years ago." With this divergence, by comparing the sequence difference between the red panda and the raccoon, the observed mutation rate for the red panda was calculated to be on the order of 109, which is apparently an underestimate compared with the average rate in mammals. This underestimation is probably due to multiple recurrent mutations as the divergence between the red panda and the raccoon is extremely deep.
The most recent molecular-systematic DNA research places the red panda into its own independent family, Ailuridae. Ailuridae are, in turn, part of a trichotomy within the broad superfamily Musteloidea that also includes the Procyonidae and a group that further subdivides into the Mephitidae and Mustelidae ; but it is not a bear.
Red pandas have no close living relatives, and their nearest fossil ancestors, Parailurus, lived 3-4 million years ago. There may have been as many as three different species of Parailurus, all larger and more robust in the head and jaw than Ailurus, living in Eurasia and possibly crossing the Bering Strait into the Americas. The red panda may be the sole surviving species – a specialized offshoot surviving the last glacial period in a Chinese mountain refuge.

Classification

In addition to Ailurus, the family Ailuridae includes seven extinct genera, most of which are assigned to three subfamilies: Amphicinae, Simocyoninae, and Ailurinae.