The centenarian tuatara, named Henry, was thought well past the mating game until he was caught canoodling with a female named Mildred last March
-- a consummation that resulted in 11 babies being hatched on Monday.
Tuatara are indigenous New Zealand creatures that resemble lizards but descend from a distinct lineage of reptile that walked the earth with the dinosaurs 225 million years ago, zoologists say.
An endangered species, the hatchlings born at the Southland Museum and Art Gallery will provide a badly needed boost to the tuatara's genetic diversity, said the gallery's tuatara curator, Lindsay Hazley.
Henry was at least 70 years old when he arrived at the museum, "a grumpy old man" who attacked other reptiles, including females, until a cancerous tumor was removed from his genitals in 2002, said Hazley.
"I went off the idea he was good for breeding," Hazley told The Associated Press, but once the tumor was removed, "he was no longer aggressive."
The museum now has 72 of the reptiles after 42 hatchings in the past two years.
Hazley hopes to use Henry regularly in the breeding program that is helping expand tuatara numbers after they had been savaged by predators.
Tuatara are estimated to number about 50,000, most of them living in predator-free sanctuaries, including offshore islands.
A male Tuatara takes 70 years to fully mature but reaches sexual maturity about age 20.
While there's no scientific data on the life span of the ancient reptiles, "they go beyond 100 well and truly," Hazley said. "They can be around for 150 to 250 years."