Tarsiers and marmosets have non-opposable thumbs. The sub-order Strepsirrhini have pseudo-opposable thumbs and include lemurs, lorises, and galagos. The family Cebidae , also having pseudo-opposable thumbs, is a family of monkeys found in Central and South America, including capuchin and squirrel monkeys.
A thumb that can be placed opposite the fingers of the same hand. Opposable thumbs allow the digits to grasp and handle objects, and are characteristic of primates.
opposable, The thumb is the first digit of the hand. ... Old World monkeys and all great apes ** Opposable with comparatively long thumbs: gibbons ...
However, not all primates have fully opposable thumbs. We can divide the primates into four groups based on their thumbs. Tarsiers and marmosets have non-opposable thumbs. The sub-order Strepsirrhini have pseudo-opposable thumbs and include lemurs, lorises, and galagos. The family Cebidae , also having pseudo-opposable thumbs, is a family of monkeys found in Central and South America, including capuchin and squirrel monkeys.