Scientists Enter a Mysterious Remote New Zealand Cave, What They Found Dates Back 1 Million Years

A team of paleontologists has uncovered a vast and previously unknown ecosystem deep inside a cave in New Zealand, revealing fossils dating back one million years. Found on the North Island near the famous Waitomo Caves, the Moa Eggshell Cave has yielded what researchers describe as a “missing volume” of New Zealand’s natural history. Buried within layers of volcanic ash, the site provides the first Early Pleistocene vertebrate fauna ever recorded in a New Zealand cave.

Discovered in the 1960s, the cave had long been overshadowed by better-known geological sites in the region. Only recently did scientists return to investigate its deeper layers, leading to the recovery of remarkably preserved fossils.

A Prehistoric Parrot Takes Center Stage

One of the most significant finds is a newly identified species of parrot, Strigops insulaborealis, which appears to be an ancient relative of the modern Kākāpō. While today’s Kākāpō is a large, flightless and nocturnal bird, its prehistoric ancestor may have been capable of flight.

The clue lies in its legs, which were described as “much weaker” than those of its contemporary counterpart, suggesting a different mode of life. According to Dr. Paul Scofield of Canterbury Museum, who co-authored the study, these fossils point to a period of rich evolutionary diversity now largely lost.

“The shifting forest and shrubland habitats forced a reset of the bird populations,” he explained. “We believe this was a major driver for the evolutionary diversification of birds and other fauna in the North Island.”

Beyond the parrot, scientists also uncovered the remains of an extinct ancestor of the Takahē, a large, flightless bird, and a species of pigeon that is closely related to Australian bronzewing pigeons.

Fossils Anchored in Volcanic Ash

Dating the fossils relied on two clear layers of volcanic ash discovered within the cave’s sediment. The animals found there are believed to have lived between 1.55 million and 1 million years ago, a period confirmed through ash deposited by eruptions that effectively locked the ecosystem in time. As reported in research published in Alcheringa: An Australasian Journal of Palaeontology, the diversity preserved in the cave is unmatched for that time frame in New Zealand.

Before this study, no Early Pleistocene vertebrate fauna had been recorded from a cave context in the region. The discovery allows researchers to bridge a large gap in the island’s biological record, where few vertebrate remains had been documented from such an early era.

Extinctions Before Human Contact

The findings challenge a long-standing narrative that widespread extinction in New Zealand began only after human arrival approximately 750 years ago. Instead, the new fossil evidence shows that dramatic loss of species was already underway. Between 33 to 50 percent of the species found in the cave are now extinct.

Lead researcher Associate Professor Trevor Worthy of Flinders University states that powerful natural forces such as super-volcanoes and climate shifts were reshaping the islands well before human impact. As Worthy explains in the Canterbury Museum’s statement:

“This study proves that natural forces like super-volcanoes and dramatic climate shifts were already sculpting the unique identity of our wildlife over a million years ago.”

By comparing the Moa Eggshell Cave’s fossil record to that of other sites, the team has concluded that cataclysmic volcanic activity and increasingly intense glacial-interglacial cycles played a major role in shaping the region’s unique and fragile biodiversity.