Goat
A goat has given birth to a rare twin goat-sheep hybrid. A goat is pictured on March 4, 2010 in Paris, France. Lionel Bonaventure/AFP/Getty Images)

A nanny goat on a family farm in Ireland gave birth to a pair of goat-sheep hybrids known as "geep," believed to be the world's only living twins of their kind, according to reports.

After a week of mating with a nearby Cheviot ram, a goat named "Daisy" delivered two medical marvels on a farm outside Claremorris, Mayo, the Irish Times reported Tuesday.

Angela Bermingham, of Bury in Manchester, owns the mother goat. She named the twins "This" and "That." The two are believed to be the only surviving twin sheep-goat crossbreeds in the world.

Michael Holmes, a long-time livestock farmer and a member of Mayo County Council, confirmed that the "geeps" were indeed the offspring of the goat and his ram.

"To have one geep survive is rare, but to have two fit and healthy twins running around must be regarded as something of a miracle," Holmes said.

Holmes said that the goat and his ram grew fond of each other.

Holmes is a former chairman of the Irish Farmers' Association's National Sheep Committee, which represents all sheep farmers "on the issues of critical importance to members such as incomes, lamb prices and premium support," according to the association's website.

"Angela’s goat used to jump into the field where my son has the sheep and ram," Holmes said. "This little geeps are very unusual. I have never seen twins before and I have seen a lot of sheep all over Ireland and all over the world."

Bermingham said she assumed Daisy might have been pregnant when the goat seemed a bit more frisky than usual.

"I knew something was going on because she didn’t come out of the field for a week," she said. "When she became obviously pregnant I knew immediately what had happened."

The "geep" owner added that the pair were born with no horns and a full set of sharp teeth, which she said was considered unusual.

Although Bermingham may have successfully bred the twin geeps, experts consider the hybrid to be rare because of a difference in chromosomes. Goats have 60 chromosomes while sheep only have 54. As a result, most pregnancies are stillborn.