This order contains diurnal arboreal and small terrestrial placental mammals called Tupayes. These omnivorous animals live in the rainforests of Southeast Asia. Tupayes have long intrigued zoologists, who have sometimes classified them close to insectivores (a group that is now obsolete) and sometimes close to primates. The development of their brain, the anatomy of their skull, the presence of an auditory bulla, their muscles and their almost opposable first digit are all criteria that place them close to primates, while their dentition and tarsus make them morphologically close to insectivores. Indeed, their incisors are caniniform, i.e. prominent and pointed, sometimes very developed, while the canines are small and premolariform.
The phylogenetic classification of these animals has been reshuffled several times as molecular tools have become increasingly sophisticated. At present, analysis of whole genomes still cannot determine with certainty the position of Scandentia within a clade called Euarchontoglires, which contains primates, Dermoptera, rodents and lagomorphs. The latest data supports the following classification, where Scandentia are the sister group to Primatomorpha (Dermoptera + primates).