Tullita the pretty tree kangaroo!
“Tree-kangaroos feature some distinct body characteristics which enable them to live in trees, unlike their ground-dwelling kangaroo cousins. These include: their exceptionally long, pendulous tail facilitating balance; stronger forelimbs, shorter and broader hind feet, longer, curved claws on feet/paws and spongy soles/‘palms’- all features that help with balancing and gripping and therefore climbing
Tree-kangaroos supposedly evolved from kangaroos that led a terrestrial (living on the ground) lifestyle. As to why they "re”-turned to arboreality (life in the trees) no-one knows. Recent DNA research suggests a closer relationship of tree-kangaroos with rock-wallabies (genus Petrogale) than with any other macropods and therefore they are conceived as sister groups within the macropods. This and the rock-wallabies’ capability to master rocky terrain and even small leaning trees might present a hint towards a relatively early split of a tree-kangaroo/rock-wallaby ancestor from the main kangaroo lineage.“
More here - http://www.tree-kangaroo.net/tkInfo.html