World's Smallest Species of Monkey Gives Birth To Two Tiny Babies

The babies weighed just 15 grams and were smaller than a human thumb when they were born.

Two members of the world's smallest species of monkey have welcomed two tiny infants.

Iti, a pygmy marmoset, gave birth to the babies on February 26 and has since been co-parenting with her partner, Gomez, according to the Symbio Wildlife Park in Sydney, Australia, where the tiny family lives.

Read: Zoo Shares Adorable Footage Of 6-Week-Old Baby Gorilla's Checkup

The babies weighed just 15 grams and were smaller than a human thumb when they were born, according to the park. While this might sound small, they were relatively big compared to the size of their mom.

"Being born at this size is equivalent to a human giving birth to a ten year old child," staff at Symbio said in a release.

Gomez, a long-time bachelor at the wildlife park, was introduced to Iti last year when she arrived from New Zealand - and it was love at first sight.

Read: Baby Monkey Journeys On a Dog's Back

The zoo suspected the couple was expecting when they noticed Iti's mini baby bump. 

Video shows the babies refusing to let go of their mom as she carries them around the enclosure. 

Pygmy marmosets, which only grow to 100 grams, are classified as endangered. The Symbio Wildlife Park says the birth of the babies is important to the survival of the species.

Watch: First Baby Snow Monkey Born at Lincoln Park Zoo