Smaller than the Philippine Tarsier, the Pygmy Tarsier (Tarsius Pumilus) was thought to be long gone until one was seen in the forests of Lore Lindu National Park, Sulawesi, Indonesia by a Texas A&M anthropologist.

From the DMC News:

The pygmy tarsiers, furry Furby/gremlin-looking creatures about the size of a small mouse and weighing less than 2 ounces, have not been observed since they were last collected for a museum in 1921. Several scientists believed they were extinct until two Indonesian scientists trapping rats in the highlands of Sulawesi accidentally trapped and killed a pygmy tarsier in 2000.

From Wikipedia:

The two males and single female (a fourth escaped) were captured using nets, and were radio collared to track their movements. As the first live Pygmy Tarsiers seen in 70-plus years, these captures dispelled the theory among some primatologists that the species was extinct.