For a long time, New Zealand’s ancient past felt incomplete, with only fragments of fossils and big gaps. Now, a cave near Waitomo on the North Island has changed that. Inside the cave, scientists found remains of wildlife that lived around one million years ago. This discovery feels like finding a lost chapter in New Zealand's history. The fossils show the land once had very different ecosystems, with dense forests and changing climates. Violent volcanic eruptions also reshaped life here long before humans arrived. The cave itself is special. Researchers believe it is the oldest cave found on New Zealand’s North Island. Even more exciting, the fossils were trapped between two layers of volcanic ash—one from an eruption 1.55 million years ago and another about 1 million years ago. This ash "sandwich" gave scientists rare, precise dating. Inside, they found remains of at least 12 bird species and four frog species. These fossils reveal that New Zealand’s wildlife went through big cycles of extinction and renewal. A new study published in Alcheringa says that up to half the ancient species had disappeared before humans arrived. Associate Professor Trevor Worthy from Flinders University says the ancient birds were very different from today’s. They were not just old versions of current birds but an entirely different group that did not survive to the present. The study shows extinction was common in the past, driven by rapid climate changes and huge volcanic eruptions covering large areas with thick ash. Dr Paul Scofield from Canterbury Museum calls it a "reset" for the forests and wildlife. Habitats vanished quickly, forcing animals to adapt or die out. One exciting find is a new parrot species called Strigops insulaborealis, an ancient relative of today’s Kākāpō. This ancestor had a lighter body and weaker legs, possibly able to fly better than the famous flightless Kākāpō of today. This discovery changes how we see the Kākāpō’s history. The cave also had fossils of an extinct ancestor of the Takahē and a pigeon related to Australian bronzewing pigeons, showing past connections between ecosystems. This discovery opens a new window into New Zealand’s ancient world and the forces that shaped its unique life.