study considered the red panda to be more closely related to bears. A 1995 mitochondrial DNA analysis revealed that the red panda has close affinities with procyonids. Further genetic studies in 2005, 2018 and 2021 have placed the red panda within the clade Musteloidea, which also includes Procyonidae, Mustelidae (weasels and relatives) and Mephitidae (skunks and relatives). Fossil record The family Ailuridae appears to have evolved in Europe in either the Late Oligocene or Early Miocene, about . The earliest member Amphictis is known from its skull and may have been around the same size as the modern species. Its dentition consists of sharp premolars and carnassials (P4 and m1) and molars adapted for grinding (M1, M2 and m2), suggesting that it had a generalised carnivorous diet. Its placement within Ailuridae is based on the grooves on the side of its canine teeth. Other early or basal ailurids include Alopecocyon and Simocyon, whose fossils have been found throughout Eurasia and North America dating from the Middle Miocene, the latter of which survived into the Early Pliocene. Both have similar teeth to Amphictis and thus had a similar diet. The puma-sized Simocyon was likely a tree-climber and shared a "false thumb"—an extended wrist bone—with the modern species, suggesting the appendage was an adaptation to arboreal locomotion and not to feed on bamboo. Later and more advanced ailurids are classified in the subfamily Ailurinae and are known as the "true" red pandas. These animals were smaller and more adapted for an omnivorous or herbivorous diet. The earliest known true panda is Magerictis from the Middle Miocene of Spain and known only from one tooth, a lower second molar. The tooth shows both ancestral and new characteristics having a relatively low and simple crown but also a lengthened crushing surface with developed tooth cusps like later species. Later ailurines include Pristinailurus bristoli which lived in eastern North America from the late Miocene to the Early Pliocene and species of the genus Parailurus which first appear in Early Pliocene Europe, spreading across Eurasia into North America. These animals are classified as a sister taxon to the lineage of the modern red panda. In contrast to the herbivorous modern species, these ancient pandas were likely omnivores, with highly cusped molars and sharp premolars. The earliest fossil record of the modern genus Ailurus dates no earlier than the Pleistocene and appears to have been limited to