The birth of the first litter of black and white ruffed lemurs at Mogo Zoo is a crucial step in helping secure the future of the critically endangered species.
Such births are kept under wraps until zookeepers are confident about the health of the new babies.
But, this week, Mogo Zoo introduced the new twins to the public for the first time under the watchful eye of their mother, Tame.
The two young lemurs are completely dependent on their mother and will not leave Tame's sight for four months.
Mogo's animal operations manager Paul Whitehorn said Tame and the father of the twins, Itasi, were both being very watchful as the yet-to-be-named siblings became more playful.
Mr Whitehorn said there were very few black and white ruffed lemurs left in the wild in Madagascar, for reasons including habitat loss due to agricultural, mining and logging activities.
"They are also hunted by poachers for their meat," he said.
The small lemurs are unusual in the primate world because they build a nest for their young.
This week's introduction of the newborns to the public comes days after Mogo Zoo won a bronze award in the Tourist Attraction category of the NSW Tourism Awards.