What Is A Finger Monkey?

There isn't really any actual species named 'finger monkey'. I have yet to get an actual answer when I ask what species they are referring to when they say that but they may only know the term 'finger monkey'. :-)
I think most people may be referring to something like a pygmy marmoset (or some a common marm or something) when they use that term but it some could mean one thing to one and another to some others since it isn't a technical term or species so would depend on what an individual person was referring to.
There is more than one species (or sub) that might be referred to as 'finger' sized. Like when people use the made up terms like 'teacup' in dogs when it doesn't actually exist in any breed as a classification so the meaning is variable (and a red flag).
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