Multiple choice general knowledge Which one of these is the smallest breed of monkeys? Gremlin Philippine Tarsier Tarsiers Pygmy Marmoset Reveal answer Fill a bubble to check yourself D Correct answer Explanation The Pygmy Marmoset (Cebuella pygmaea) is the world's smallest monkey species, native to South American rainforests. Adults weigh only about 100 grams and measure 12-15 cm.