It’s known as a mountain monkey after its Spanish name monito del monte, but it is a marsupial. Evolutionists believe that it is a living fossil,
“the only surviving member of an otherwise extinct lineage dating back more than 40 million years [sic]. Only slightly larger than a mouse, this little marsupial is an excellent climber. The base of the prehensile – or grasping – tail is capable of storing fat, which enables the animals to hibernate during the winter when food is scarce.”