CNN  — 

An ancient grove of pine trees whose ancestors are thought to have stood tall among dinosaurs some 200 million years ago has been saved from Australian bushfires in a covert firefighting mission.

Firefighters in New South Wales (NSW) were enlisted by the local government to save the prehistoric Wollemi Pine grove, which exists in a secret location within the 5,000-square-kilometer (1,930-square-mile) Wollemi National Park northwest of Sydney.

There are fewer than 200 Wollemi Pines left in the wild.

The oldest fossil of the rare pine species dates back 90 million years and the pines are thought to have existed during the Jurassic period.

Large air tankers of fire retardant were dropped inside the remote grove as part of the mission, while specialist firefighters attached to helicopters were winched down to set up an irrigation system to protect the trees from catching alight.

Specialist firefighters were winched down to set up an irrigation system.

Swathes of the Wollemi National Park have been affected by the devastating bushfires and some of the precious pine trees have been charred.

“Wollemi National Park is the only place in the world where these trees are found in the wild and, with less than 200 left, we knew we needed to do everything we could to save them,” Matt Kean, the NSW environment minister, said in a statement.

Some of the rare pines have been charred by the bushfire.

“The pines, which prior to 1994 were thought to be extinct and whose location is kept secret to prevent contamination, benefited from an unprecedented environmental protection mission,” he added.

The NSW government had carried out a detailed scientific assessment and, while some trees have been damaged, the species has survived, he said.