Wellington - Henry, a tuatara reptile relic of the dinosaur age said to be 111-years-old, is to become a father for the first time, a newspaper reported on Wednesday.

Tuatara (Sphenodon punctatus) usually become sexually mature at the age of about 20, but Henry, who lives at the Southland Museum in Invercargill, was a slow developer and did not discover sex until March when he had a romp with Mildred, who is in her 70s.

As a result, Mildred laid 12 eggs last month and although one has perished, the rest are doing well in a museum incubator and should hatch in about six months, curator Lindsay Hazley told the Southland Times.

"The fact they have come this far is a good positive sign," he said. "As each week goes by I get more confident the eggs will last."

Hazley said Henry probably discovered the joys of mating after having a cancerous growth removed from his bottom.

He said Henry would probably mate again in next year's breeding season and he now had three females in his enclosure to entice him. "With these guys foreplay might take years," he said. "One has to be patient."

Tuatara, which are native to New Zealand, are the last surviving members of the beak-headed reptile species known as the Order Sphenodontia, which was prevalent during the age of the dinosaurs, 200 million years ago.

All species apart from the tuatara became extinct about 60 million years ago.

The Department of Conservation estimates there are about 100,000 tuatara and has launched breeding programmes on predator-free offshore islands and other sanctuaries. (dpa)