Lemurs share resemblance with other primates, but evolved independently from monkeys and apes. Thumb sucking is a behavior found in humans, chimpanzees, captive ring-tailed lemurs, and other primates. The Cheirogaleidae are the family of strepsirrhine primates containing the various dwarf and mouse lemurs. Featured species included guanaco, Formosan sika deer, pied ruffed lemurs, and blue-eyed black lemurs. It is observed consistently in hyenas, lemurs and the bonobo. Whines are highly variable between individual ruffed lemurs. As in the case of lemurs, the origin of New World monkeys is unclear. Generally, the fossa preys upon larger lemurs and rodents in preference to smaller ones. Another principal threat to the survival of ruffed lemurs is hunting. They are carnivorous, feeding mostly on small lemurs and tenrecs. Subfossil sites in Madagascar have yielded the remains of more than just extinct lemurs. It is omnivorous and the most terrestrial of extant lemurs. The estimated weights for the subfossil lemurs have varied. It is however not well developed in diurnal forms like many lemurs. Humans lie well above the line indicating that humans are more encephalized than lemurs.