Animal locomotion many of these same principles may be applied to climbing without trees, such as on rock piles or mountains. The earliest known tetrapod with specializations that adapted it for climbing trees, was "Suminia", a synapsid of the late Permian, about 260 million years ago. Some invertebrate animals are exclusively arboreal in habitat, for example, the tree snail. "Brachiation" (from "brachium", Latin for "arm"), is a form of arboreal locomotion in which primates swing from tree limb to tree limb using only their arms. During brachiation, the body is alternately supported under each forelimb. This is the primary means of locomotion
Asháninka arboreal chinchilla rat and lips, large claws, and a line of white fur running down its head. It is in length, with a tail of . It weighs . Ashaninka arboreal chinchilla rats live in dwarf forest and are hunted by long-tailed weasels. When described, it was placed in the family Abrocomidae, but was considered different enough from existing species for the creation of the genus "Cuscomys". Since then, the Machu Picchu arboreal chinchilla rat ("Cuscomys oblativus"), a species of chinchilla rats originally placed in the genus "Abrocoma", has been shown to be a member of "Cuscomys". Although it was considered extinct by