The Sumatran mountain squirrel (''Sundasciurus altitudinis'') is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

in the family Sciuridae. Its skull reaches sizes between , overlapping with that of the Palawan montane squirrel. It was originally described as a

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of ''

Sundasciurus tenuis The slender squirrel (''Sundasciurus tenuis'') is a species of rodent in the family Sciuridae. It is arboreal and found in Indonesia, Singapore, Malaysia, and Thailand Thailand ( ), historically known as Siam () and officially the Ki ...

''.

References

Sundasciurus Fauna of Sumatra Rodents of the Philippines Taxa named by C. Boden Kloss Taxa named by Herbert C. Robinson Mammals described in 1916 {{Squirrel-stub