A 100 million-year-old fossil forest, including large trees and rare insects, has been discovered on the Chatham Islands of New Zealand.

The forest dates back to the Cretaceous period, between 145-65 million years ago. During this period, extreme greenhouse conditions prevailed. Flowering plants began to emerge and spread across landscapes. The end of the period resulted in the mass extinction of dinosaurs and other prehistoric life forms.

A research team led by professor Jeffrey Stilwell and palaeobotanist Dr. Chris Mays from Monash University in Australia made the discovery while they were studying a bone bed and plant remains on the nearby Pitt Island.

The discovery is the first fossil evidence of a prehistoric forest close to the South Pole. The preserved fossil forest was found at a distance of around 745 miles from the South Pole. During the Cretaceous period, many continents including New Zealand and the Chatham Islands (Zealandia), South America, Australia and Antarctica were all part of the southern landmass called Gondwana.

"One hundred million years ago, the Earth was in the grip of a greenhouse effect - a planet of extreme heat with minimal ice (except in the high altitudes) and sea levels of up to 200 meters higher than today," Stilwell said in a statement.

"Rainforests inhabited by dinosaurs existed in sub-polar latitudes and polar ecosystems were adapted to long months of winter darkness and summer daylight."

Experts hope the study will help in understanding how plants and animal species adapted to the extreme greenhouse conditions in the past. With increase in global temperatures, this new study might give clues as to how the flora and fauna will adapt to climate change in the future.