Hatching of endangered turtle species is first for North American zoo NEW YORK, Dec. 17 (UPI) -- The birth of endangered Chinese big-headed turtles at a New York zoo is a rare hatching and a first for a North American zoo, wildlife experts said. Five of the Platysternon megacephalum turtles -- a species with a skull of solid bone so large in proportion to its body it cannot be withdrawn into its shell for protection -- hatched at the Wildlife Conservation Society's Prospect Park Zoo in November, the society said in a release Monday. The breeding of the Chinese turtles is part of a global effort to save critically endangered turtle species from extinction by building assurance colonies to maintain a genetically viable population until conservationists can stabilize wild populations, the society said. Chinese big-headed turtles, native to China, Cambodia, Laos, Myanmar, Thailand and Vietnam, are classified as endangered by the International Union for the Conservation of Nature. "With so many of the world's freshwater turtles and tortoises facing extinction, these hatchlings represent significant progress for the conservation of the species," Denise McClean, director of the Prospect Park Zoo, said.